Author Topic: Blue Origin's BE-7 engine  (Read 74601 times)

Offline Nilof

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Blue Origin's BE-7 engine
« on: 05/10/2019 05:27 am »
Blue origin announced a new hydrolox engine, the BE-7, which will power the Blue Moon lander, and should also be versatile enough to be used for other applications.



Here's what we learned from presentation + website:

Dual expander cycle.
Thrust: 40 kN
Specific impulse: 453 s
Propellant: LH2 + LOX

Deep throttle capability for lunar landings. Parts are mostly 3D printed. If you see more technical details pop up, post them here.
« Last Edit: 05/10/2019 05:28 am by Nilof »
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline vaporcobra

Re: Blue Origin's BE-7 engine
« Reply #1 on: 05/10/2019 05:32 am »
First static fire is "later this year".

Offline Nilof

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Re: Blue Origin's BE-7 engine
« Reply #2 on: 05/10/2019 05:41 am »
WANTED INFO: Biggest unknown piece of information for this engine is the O/F (oxidizer to fuel) ratio. Will be added here if found.

Since the main application is for a lunar lander and LOX ISRU is easy on the entire moon, the O/F ratio is important info for any mission payload calculations that assume oxygen depots. The O/F ratio could also be variable like the J-2, in which case we would be interested in the whole range.

If we ever get a situation where you can ask Bezos or a Blue representative random questions about technical details, this would be a great one to ask.
« Last Edit: 05/10/2019 05:44 am by Nilof »
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline FutureSpaceTourist

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Re: Blue Origin's BE-7 engine
« Reply #3 on: 05/10/2019 08:35 am »
Re-posting in this thread for ease of reference:

https://twitter.com/erdayastronaut/status/1126594675048157185

Quote
This is @blueorigin’s BE-7 engine for the #bluemoon lunar lander up close and personal!

Offline tonya

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Re: Blue Origin's BE-7 engine
« Reply #4 on: 05/10/2019 02:14 pm »
Just from the way the pumps and control valves are mounted, it looks like something that was designed with servicing in mind as a design objective. Quite striking how simple it looks and how accessible and obvious the major components are.

Offline Nilof

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Re: Blue Origin's BE-7 engine
« Reply #5 on: 05/10/2019 04:01 pm »
Re-posting in this thread for ease of reference:

https://twitter.com/erdayastronaut/status/1126594675048157185

Quote
This is @blueorigin’s BE-7 engine for the #bluemoon lunar lander up close and personal!

Following up on Tonya's comment, note how the pipes are color coded depending on whether they carry hydrogen or oxygen.

Also, this is a good opportunity to link to this nice educational article about expander cycle engines:
https://blogs.nasa.gov/J2X/2014/03/24/inside-the-leo-doghouse-the-art-of-expander-cycle-engines/

And attached, a diagram of the dual expander cycle:
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline Nilof

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Re: Blue Origin's BE-7 engine
« Reply #6 on: 05/10/2019 04:12 pm »
Link to presentation starting exactly at engine unveil:

https://www.youtube.com/watch?v=GQ98hGUe6FM?t=2369

Also includes a rotating view of the engine so that you can view it from all angles. Looking at the oxidizer turbopump, that definitely looks like a split expander cycle on the oxidizer side, since the pump seems to have two stages.

Also looking at the pipes to propellant tanks, it looks like the engine provides autogenous pressurization? That would definitely be an advantage of going with a split expander, since you get hot GOX and GH2 for free which can be used to pressurize the propellant tanks.

« Last Edit: 05/10/2019 04:32 pm by Nilof »
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline tonya

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Re: Blue Origin's BE-7 engine
« Reply #7 on: 05/10/2019 05:03 pm »
Plumbing screengrabs for easier reference.

Offline russianhalo117

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Re: Blue Origin's BE-7 engine
« Reply #8 on: 05/10/2019 08:15 pm »
Re-posting in this thread for ease of reference:

https://twitter.com/erdayastronaut/status/1126594675048157185

Quote
This is @blueorigin’s BE-7 engine for the #bluemoon lunar lander up close and personal!

Following up on Tonya's comment, note how the pipes are color coded depending on whether they carry hydrogen or oxygen.

Also, this is a good opportunity to link to this nice educational article about expander cycle engines:
https://blogs.nasa.gov/J2X/2014/03/24/inside-the-leo-doghouse-the-art-of-expander-cycle-engines/

And attached, a diagram of the dual expander cycle:
The only thing that we don't know is the exact type of dual expander cycle (DEC) engine although it seems to be the simplest type of DEC when viewing the display engine, but the display engine may not be a final complete fidelity engine.

Reference video:

Scott Manley' s take:
« Last Edit: 05/10/2019 08:30 pm by russianhalo117 »

Offline Rik ISS-fan

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Re: Blue Origin's BE-7 engine
« Reply #9 on: 05/10/2019 09:54 pm »
AFAIK the BE-7 uses the most complex expander-cycle option; the dual expander cycle.
The most simple is expander bleed; aka evaporating some of the fuel or oxidizer to drive the turbopump(s). The evaporated gas is dumped in the trust direction, but not used inside the combustion chamber.
The next level in complexity is a standard expander cycle, the fuel or the oxidizer is evaporated, drives the turbopump(s) and is injected into the combustion chamber. The most complex is dual expander, both the fuel and oxidizer are expanded, they drive a fuel and oxidizer turbopump and the gasses are injected into the combustion chamber, reaching the high ISP of the GOxGH2 fuel combo.
(RL-10 has a geared GH2(G) turbine driving a LH2 turbopump connected with a gear to the LO2 turbopump.
Vince has a LOx and a LH2 turbopump both driven by a GH2 turbine. With a proportional valve the GH2 flow is regulated between the two turbopumps. Now in Europe the ETID is being developed under the ESA FLPP program, it uses another version of the single expander cycle (afaik).

Have others envisioned the use of BE-7 as upper-stage engine for a New Shepard sized and derived small launcher? AKA ~1000-2000lb (0.5-1mT) to 800km SSO. Is this possible?

Edit to add: Blue Origin what is the thust level of BE-7. 10k lbf  (44 482 N) or 40kN (8992 lbf)?
The current numbers are a mess. If its 10k lbf state its 44,5kN please.
Note that BE-- is a very small low thrust engine. RL-10 is 15k - 25k lbf (~65-110kN), and Vince is 180kN (~40 500 lbf). And the Ariane 5 ECA HM7B gasgenerator engines provide ~64kN (14.3k lbf) so BE-7 is less powerful.
What I find funny is the fact that the Callisto demonstrator (Europa and Japan reusable suborbital stage demonstrator) will use re-ignitable 40kN LOxLH2 engine. Details about this engine are vague.

edit2: the engine shown on the right side if the Scott Manley Expander Cycle video, is NOT Vince. Its ID#1 the thust chamber test article from the EDIT FLPP project.
« Last Edit: 05/10/2019 10:31 pm by Rik ISS-fan »

Offline DasBlinkenlight

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Re: Blue Origin's BE-7 engine
« Reply #10 on: 05/10/2019 10:41 pm »
IN all of the photos, I don't see where the propellants first enter the system...
Also trying to determine how they will start the BE-7... both ignition, and getting the expander cycles started... I don't see any gas generator or  other means of starting.... any ideas?

Offline russianhalo117

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Re: Blue Origin's BE-7 engine
« Reply #11 on: 05/10/2019 10:58 pm »
AFAIK the BE-7 uses the most complex expander-cycle option; the dual expander cycle.
The most simple is expander bleed; aka evaporating some of the fuel or oxidizer to drive the turbopump(s). The evaporated gas is dumped in the trust direction, but not used inside the combustion chamber.
The next level in complexity is a standard expander cycle, the fuel or the oxidizer is evaporated, drives the turbopump(s) and is injected into the combustion chamber. The most complex is dual expander, both the fuel and oxidizer are expanded, they drive a fuel and oxidizer turbopump and the gasses are injected into the combustion chamber, reaching the high ISP of the GOxGH2 fuel combo.
(RL-10 has a geared GH2(G) turbine driving a LH2 turbopump connected with a gear to the LO2 turbopump.
Vince has a LOx and a LH2 turbopump both driven by a GH2 turbine. With a proportional valve the GH2 flow is regulated between the two turbopumps. Now in Europe the ETID is being developed under the ESA FLPP program, it uses another version of the single expander cycle (afaik).

Have others envisioned the use of BE-7 as upper-stage engine for a New Shepard sized and derived small launcher? AKA ~1000-2000lb (0.5-1mT) to 800km SSO. Is this possible?

Edit to add: Blue Origin what is the thust level of BE-7. 10k lbf  (44 482 N) or 40kN (8992 lbf)?
The current numbers are a mess. If its 10k lbf state its 44,5kN please.
Note that BE-- is a very small low thrust engine. RL-10 is 15k - 25k lbf (~65-110kN), and Vince is 180kN (~40 500 lbf). And the Ariane 5 ECA HM7B gasgenerator engines provide ~64kN (14.3k lbf) so BE-7 is less powerful.
What I find funny is the fact that the Callisto demonstrator (Europa and Japan reusable suborbital stage demonstrator) will use re-ignitable 40kN LOxLH2 engine. Details about this engine are vague.

edit2: the engine shown on the right side if the Scott Manley Expander Cycle video, is NOT Vince. Its ID#1 the thust chamber test article from the EDIT FLPP project.
Let's use the most complex variant of DEC known CDSEC or Closed Dual Split Expander Cycle which is the theoretically most powerful, optimized, and efficient version of DEC for ideally upper stage uses as a sustainer engine. The display engine presently shows the simplest variant of DEC.
« Last Edit: 05/10/2019 11:02 pm by russianhalo117 »

Offline Rik ISS-fan

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Re: Blue Origin's BE-7 engine
« Reply #12 on: 05/10/2019 11:09 pm »
I think the mock-up of BE-7 misses the sensor and electronic cables and the LOx and LH2 infeeds. The mockup only only shows: four sections of the combustion chamber assembly; the GOx and GH2 lines and regulator valves.
The engine for Callisto must be able to throttle down 40% or to 40% (40kN max => 24kN or 16kN |10k lbf => 6k or 4k lbf) 

@russianhelo117 can you explain the difference between DEC and CDSEC? What is de spilt meaning?
The BE-7 definitely looks like a closed cycle engine. And AFAIK the schemetic you show has lower ISP because some of the fuel and oxidizer will be injected in liquid form instead of all gas, what the BE-7 has.

I've added a screenshot with the back side of the BE-7, several unused sensor and feed-line ports are visible.
I think this looks like a dual tap-off expander cycle. All fuel and lox are evaporated inside the double walled combustion chamber. Some of the expanded fuel and oxidizer are used to drive the turbopumps to increase gas injection pressure into the combustion chamber.
Edit3: The liquid pumps and liquid propellant lines are missing in the rendering. I think there are blinding plates mounted in the place of the liquid turbines. This looks like a test engine with pre pressurized liquid propellants.
« Last Edit: 05/10/2019 11:51 pm by Rik ISS-fan »

Offline russianhalo117

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Re: Blue Origin's BE-7 engine
« Reply #13 on: 05/10/2019 11:29 pm »
I think the mock-up of BE-7 misses the sensor and electronic cables and the LOx and LH2 infeeds. The mockup only only shows: four sections of the combustion chamber assembly; the GOx and GH2 lines and regulator valves.
The engine for Callisto must be able to throttle down 40% or to 40% (40kN max => 24kN or 16kN |10k lbf => 6k or 4k lbf) 

@russianhelo117 can you explain the difference between DEC and CDSEC? What is de spilt meaning?
The BE-7 definitely looks like a closed cycle engine.
It fixes deficiencies in a standard Closed DEC, eliminates the need for boost pumps and other manipulations for effective combustion at the MCC. The fuel side is identical to the oxidizer side in term of components, albeit adjusted for the fuel type. Like its FFSCC cousin, CDSEC is highly efficient at the tradeoff of being the most complex version of an EC engine and the fact that the engine would have to be tested like Raptor as the entire engine. Boost pumps can be added for higher thrust without the losses of bleed Cycle engines.
Scrolldown and read:
https://blogs.nasa.gov/J2X/2014/03/24/inside-the-leo-doghouse-the-art-of-expander-cycle-engines/

Offline Lar

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Re: Blue Origin's BE-7 engine
« Reply #14 on: 05/11/2019 01:00 am »
I just wanna say I love that guy[1] and his diagrams, his writing makes me smile a lot."happy little turbopumps" indeed... And now I understand the tradeoffs around expanders a lot better. Do we have enough images to tell which variant the BE-7 is? are both sides split?

1 - I refer to the link Nilof gave, here it is again:  https://blogs.nasa.gov/J2X/2014/03/24/inside-the-leo-doghouse-the-art-of-expander-cycle-engines/
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Offline Nilof

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Re: Blue Origin's BE-7 engine
« Reply #15 on: 05/11/2019 01:40 am »
To me it looks like the BE-7 is split on the oxidizer side but not the fuel side, which is necessary because you have a lot more LOX flow than LH2 flow mass-wise, and you wouldn't want to push that much LOX through the engine walls.

The LOX side pump has five pipes going into it and is longer (meaning it's split), while the LH2 pump is stubby and has four pipes going into it.

Also, while it may have more complex plumbing, the Dual expander should have fewer moving parts & be simpler mechanically since it doesn't need a gearbox between LH2 turbopump and LOX pump, and also doesn't need crazy seals on the bearing between the LH2 side and the LOX side, which OTOH have to be purged with pressurized Helium in most engines.

Also, the dual expander can provide pure GH2 and GOX for autogenous pressurization, which as mentioned seems to be the case here (pipe leading both in and out on both sides). I suspect that Blue is aiming to completely eliminate helium on the Blue moon spacecraft. Between this and the fuel cells, it does makes me wonder if they're planning to leapfrog ULA's ACES and go with autogenous pressurization to eliminate helium on their other hydrogen stages as well.

This makes me suspect that one of the BE-5 or BE-6 could be a GOX/GH2 hot gas thruster to be used for all their in-space stages.
« Last Edit: 05/11/2019 01:46 am by Nilof »
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline TrevorMonty

Re: Blue Origin's BE-7 engine
« Reply #16 on: 05/11/2019 02:36 am »
Rik thanks for Scott Manley link.

He did a good job of explaining different expander engines.

One thing he pointed out was difference  between EL10 ISP465 and BE7 ISP453. Said it was because of RL10 extra large nozzle which isn't practical for lander.
In theory they could add larger nozzle for OTV and so increase ISP.

Offline Nilof

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Re: Blue Origin's BE-7 engine
« Reply #17 on: 05/17/2019 12:09 am »
The labels on the mockup seem to make absolutely no sense. They have arrows but they don't seem to indicate flow direction.
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline Nilof

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Re: Blue Origin's BE-7 engine
« Reply #18 on: 05/17/2019 12:41 am »
This is what I assume that the actual flows are on H2 side. With phases from liquid to compressible liquid to supercritical to gas.

I'm slightly confused by that pipe of supercritical H2 to the tanks for autogenous pressurization. Feels like a waste of pressure budget to use that instead of GH2, unless you literally want to pressurize fuel tanks above the engine's chamber pressure. Maybe related to throttling down to very low chamber pressures? Or maybe the flow should be reversed, and it's for running in pressure-fed mode during startup?
« Last Edit: 05/17/2019 12:52 am by Nilof »
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline Nilof

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Re: Blue Origin's BE-7 engine
« Reply #19 on: 05/17/2019 01:55 am »
OK, now I'm surprised. Neither side is split?

So cycle is basically like attached (closed dual expander with autogenous pressurization), with some extra shenanigans in the connection to the tanks and some extra valves?

That would have the benefit of allowing the engine to be gas/gas, which could generally make it more reliable. But mass flow of oxidizer through the CC walls would be kind of crazy and the design might have a lower size cap than regular expanders.
« Last Edit: 05/17/2019 02:24 am by Nilof »
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline Pueo

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Re: Blue Origin's BE-7 engine
« Reply #20 on: 05/17/2019 03:15 pm »
This is what I assume that the actual flows are on H2 side. With phases from liquid to compressible liquid to supercritical to gas.

I'm slightly confused by that pipe of supercritical H2 to the tanks for autogenous pressurization. Feels like a waste of pressure budget to use that instead of GH2, unless you literally want to pressurize fuel tanks above the engine's chamber pressure. Maybe related to throttling down to very low chamber pressures? Or maybe the flow should be reversed, and it's for running in pressure-fed mode during startup?

The 10,000 lbs thrust of the engine is below that where a split expander cycle would be needed.

I believe that pipe is to the combustion chamber, not the tanks.  The purpose would be to have a portion of the expanded gases bypass the turbo to allow for lower throttle.

Edit: added diagram
« Last Edit: 05/17/2019 04:14 pm by Pueo »
Could I interest you in some clean burning sub-cooled propalox and propalox accessories?
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Offline Nilof

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Re: Blue Origin's BE-7 engine
« Reply #21 on: 05/17/2019 04:34 pm »
This is what I assume that the actual flows are on H2 side. With phases from liquid to compressible liquid to supercritical to gas.

I'm slightly confused by that pipe of supercritical H2 to the tanks for autogenous pressurization. Feels like a waste of pressure budget to use that instead of GH2, unless you literally want to pressurize fuel tanks above the engine's chamber pressure. Maybe related to throttling down to very low chamber pressures? Or maybe the flow should be reversed, and it's for running in pressure-fed mode during startup?

The 10,000 lbs thrust of the engine is below that where a split expander cycle would be needed.

I believe that pipe is to the combustion chamber, not the tanks.  The purpose would be to have a portion of the expanded gases bypass the turbo to allow for lower throttle.

Edit: added diagram

Okay, I get what you're saying and it looks like you're right.

This is a beautifully simple engine. Dual expander with no seals. Bypass valve to throttle.  gas/gas injectors. Not a lot that can go wrong in operation.
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline Pueo

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Re: Blue Origin's BE-7 engine
« Reply #22 on: 05/17/2019 05:27 pm »
On the other hand if flat plates on the ends of the turbopumps are in fact inlets, that would suggest that there is a split.  This kinda makes sense given there appears to be 2-stages to the oxidizer pump with the lower pressure getting sent to the combustion chamber and the higher to the cooling jacket.  It would also make the indicated directions on the pipes make sense.
Could I interest you in some clean burning sub-cooled propalox and propalox accessories?
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Offline Nilof

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Re: Blue Origin's BE-7 engine
« Reply #23 on: 05/17/2019 09:58 pm »
On the other hand if flat plates on the ends of the turbopumps are in fact inlets, that would suggest that there is a split.  This kinda makes sense given there appears to be 2-stages to the oxidizer pump with the lower pressure getting sent to the combustion chamber and the higher to the cooling jacket.  It would also make the indicated directions on the pipes make sense.

Right. I thought there was a split at first from the turbopump shape, until I started to trace out the pipes and noted that they both only had four connections.
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline b0objunior

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Re: Blue Origin's BE-7 engine
« Reply #24 on: 05/17/2019 10:20 pm »
Question, from what we know of the BE-7, does it seems like a good transfer vehicle engine?

Offline Khadgars

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Re: Blue Origin's BE-7 engine
« Reply #25 on: 05/17/2019 10:33 pm »
Not gonna lie, I'm enjoying this thread immensely even though I can only vaguely follow it  ;D
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Offline TrevorMonty

Re: Blue Origin's BE-7 engine
« Reply #26 on: 05/17/2019 11:32 pm »
The BE7 would make great US engine for New Shepard smallsat launcher. Jeff did mention this idea in passing. While it would be well within Blues capabilities, I'd be surprised if they do it given how many other projects they have ongo.



Offline Klebiano

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Re: Blue Origin's BE-7 engine
« Reply #27 on: 06/02/2019 04:24 am »
The valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?

Offline Robotbeat

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Re: Blue Origin's BE-7 engine
« Reply #28 on: 06/02/2019 04:27 am »
The valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?
They could be servo motors with a NEMA like casing.

I would bet those are either stand-ins for the real thing or it's a relatively crude prototype. Those kinds of casings aren't terribly flightweight. And that matters a LOT for a lunar vehicle.
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Offline b0objunior

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Re: Blue Origin's BE-7 engine
« Reply #29 on: 06/02/2019 04:32 am »
The valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?
They could be servo motors with a NEMA like casing.

I would bet those are either stand-ins for the real thing or it's a relatively crude prototype. Those kinds of casings aren't terribly flightweight. And that matters a LOT for a lunar vehicle.
How much mass are they?

Offline ZachF

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Re: Blue Origin's BE-7 engine
« Reply #30 on: 06/02/2019 04:38 pm »
This is what I assume that the actual flows are on H2 side. With phases from liquid to compressible liquid to supercritical to gas.

I'm slightly confused by that pipe of supercritical H2 to the tanks for autogenous pressurization. Feels like a waste of pressure budget to use that instead of GH2, unless you literally want to pressurize fuel tanks above the engine's chamber pressure. Maybe related to throttling down to very low chamber pressures? Or maybe the flow should be reversed, and it's for running in pressure-fed mode during startup?

The 10,000 lbs thrust of the engine is below that where a split expander cycle would be needed.

I believe that pipe is to the combustion chamber, not the tanks.  The purpose would be to have a portion of the expanded gases bypass the turbo to allow for lower throttle.

Edit: added diagram

Full Flow expander cycle...?  ;)
artist, so take opinions expressed above with a well-rendered grain of salt...
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Offline Klebiano

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Re: Blue Origin's BE-7 engine
« Reply #31 on: 06/04/2019 02:55 am »
The valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?
They could be servo motors with a NEMA like casing.

I would bet those are either stand-ins for the real thing or it's a relatively crude prototype. Those kinds of casings aren't terribly flightweight. And that matters a LOT for a lunar vehicle.
How much mass are they?

Not much, for example, a NEMA 34 can weight 5kg, but I think that the problem is not the weight, it's the environment that these motors have to withstand.

Offline Robotbeat

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Re: Blue Origin's BE-7 engine
« Reply #32 on: 06/04/2019 03:33 am »
The valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?
They could be servo motors with a NEMA like casing.

I would bet those are either stand-ins for the real thing or it's a relatively crude prototype. Those kinds of casings aren't terribly flightweight. And that matters a LOT for a lunar vehicle.
How much mass are they?

Not much, for example, a NEMA 34 can weight 5kg, but I think that the problem is not the weight, it's the environment that these motors have to withstand.
There are 6 of them, so 30kg. That makes a significant different to the engine’s thrust to weight. I suspect a different form factor would halve the mass; I think these are just for the prototype.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline Navier–Stokes

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Offline TrevorMonty

Re: Blue Origin's BE-7 engine
« Reply #34 on: 06/20/2019 11:15 am »
35sec is impressive for 1st firing.

Offline ZChris13

Re: Blue Origin's BE-7 engine
« Reply #35 on: 06/20/2019 01:36 pm »
are they using TEA-TEB (or equivalent) for ignition or was it burning combustion chamber rich there?

Offline Navier–Stokes

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Re: Blue Origin's BE-7 engine
« Reply #36 on: 06/20/2019 02:20 pm »
are they using TEA-TEB (or equivalent) for ignition or was it burning combustion chamber rich there?
It's the ignition system:
First hotfire of our #BE7 lunar landing engine just yesterday at Marshall Space Flight Center. Data looks great and hardware is in perfect condition. What you’re seeing at the bottom is a water cooling system and the green flame is the ignition system. The engine plume you see is very clear because the fuel is hydrogen. Test went full planned duration – 35 seconds. Kudos to the whole @BlueOrigin team and grateful to @NASA_Marshall for all the help!
Emphasis mine

Offline Gliderflyer

Re: Blue Origin's BE-7 engine
« Reply #37 on: 06/21/2019 12:02 am »
35sec is impressive for 1st firing.
And somewhat surprising given their somewhat cautious and methodical nature. For a first engine run, you usually want to run it for a second or two. It is usually difficult to slag an engine in the first couple seconds if something is wrong (it can run in "heatsink mode"), but it also gives you enough data to see if the engine is trending towards steady state or towards eating itself.

There also seems to be a howl during the engine run. It could always be an audio artifact or some component of the test hardware (that is somehow louder than a rocket engine), but it sounds a lot like high-frequency combustion instability. What little you can see of the plume seems to dance around a bit, which also points to instability. It ran for 35 seconds, so it isn't the "instant engine destruction" flavor of instability, but I doubt it is desirable.
I tried it at home

Re: Blue Origin's BE-7 engine
« Reply #38 on: 07/19/2019 12:13 am »
Pretty impressive! Now if only they would share some footage...

https://twitter.com/jeff_foust/status/1152007076333277184?s=20
« Last Edit: 07/19/2019 12:21 am by TG Revv »
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Offline b0objunior

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Re: Blue Origin's BE-7 engine
« Reply #39 on: 07/19/2019 12:41 am »
Pretty impressive! Now if only they would share some footage...

https://twitter.com/jeff_foust/status/1152007076333277184?s=20
Moving fast, great! Hope to see a video of that!

Offline daveklingler

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Re: Blue Origin's BE-7 engine
« Reply #40 on: 07/23/2019 11:51 pm »
Question, from what we know of the BE-7, does it seems like a good transfer vehicle engine?

I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode.  That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine.
« Last Edit: 07/24/2019 12:05 am by daveklingler »

Offline daveklingler

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Re: Blue Origin's BE-7 engine
« Reply #41 on: 07/23/2019 11:58 pm »
The valves on this engine looks a lot like a stepper motor with NEMA type enclosure, anyone knows more about these valves?
They could be servo motors with a NEMA like casing.

I would bet those are either stand-ins for the real thing or it's a relatively crude prototype. Those kinds of casings aren't terribly flightweight. And that matters a LOT for a lunar vehicle.
How much mass are they?

Not much, for example, a NEMA 34 can weight 5kg, but I think that the problem is not the weight, it's the environment that these motors have to withstand.
There are 6 of them, so 30kg. That makes a significant different to the engine’s thrust to weight. I suspect a different form factor would halve the mass; I think these are just for the prototype.

Those short little motors are more on the order of 1 kg or less, not 5, and the valves are pretty beefy. It wouldn't surprise me if a short NEMA 34 is in the right ballpark mass-wise, whether or not that particular model is on the final product. I don't see any cables or connectors, so they may not be real.

I may have motors that size in a box somewhere. Regardless, they don't weigh much.
« Last Edit: 07/24/2019 12:06 am by daveklingler »

Offline TrevorMonty

Re: Blue Origin's BE-7 engine
« Reply #42 on: 07/24/2019 12:09 am »
Question, from what we know of the BE-7, does it seems like a good transfer vehicle engine?

I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode.  That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine.
Blue have OTV on their todo list. Most likely they will use this engine for both OTV and lander along with other common systems. Both vehicles will need handle LH boiloff over a few days.


Offline daveklingler

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Re: Blue Origin's BE-7 engine
« Reply #43 on: 07/24/2019 01:22 am »
Question, from what we know of the BE-7, does it seems like a good transfer vehicle engine?

I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode.  That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine.
Blue have OTV on their todo list. Most likely they will use this engine for both OTV and lander along with other common systems. Both vehicles will need handle LH boiloff over a few days.

Which I guess they plan to handle with fuel cell-powered IVF.  I wonder whether a little boiloff H2 figures into the way this engine is designed, as well. Doesn't have to be, but that would be elegant.

Come to that, tying together the fuel cells, the IVF, the boiloff and the BE-7 could be pretty interesting.
« Last Edit: 07/24/2019 01:28 am by daveklingler »

Offline b0objunior

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Re: Blue Origin's BE-7 engine
« Reply #44 on: 07/24/2019 06:26 am »
Question, from what we know of the BE-7, does it seems like a good transfer vehicle engine?

I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode.  That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine.
Blue have OTV on their todo list. Most likely they will use this engine for both OTV and lander along with other common systems. Both vehicles will need handle LH boiloff over a few days.

Which I guess they plan to handle with fuel cell-powered IVF.  I wonder whether a little boiloff H2 figures into the way this engine is designed, as well. Doesn't have to be, but that would be elegant.

Come to that, tying together the fuel cells, the IVF, the boiloff and the BE-7 could be pretty interesting.
I'm not sure what you mean by bypass. Sorry, I not really good with rocket engines language.

Offline russianhalo117

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Re: Blue Origin's BE-7 engine
« Reply #45 on: 07/24/2019 10:09 pm »
Question, from what we know of the BE-7, does it seems like a good transfer vehicle engine?

I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode.  That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine.
Blue have OTV on their todo list. Most likely they will use this engine for both OTV and lander along with other common systems. Both vehicles will need handle LH boiloff over a few days.

Which I guess they plan to handle with fuel cell-powered IVF.  I wonder whether a little boiloff H2 figures into the way this engine is designed, as well. Doesn't have to be, but that would be elegant.

Come to that, tying together the fuel cells, the IVF, the boiloff and the BE-7 could be pretty interesting.
I'm not sure what you mean by bypass. Sorry, I not really good with rocket engines language.
With some expander cycle engines like RL10 family and BE-7 there is a bypass valve and line used during prestart to spin up the turbopumps and the ignition process. The BPV is closed upon start.

Offline b0objunior

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Re: Blue Origin's BE-7 engine
« Reply #46 on: 07/25/2019 06:15 am »
Question, from what we know of the BE-7, does it seems like a good transfer vehicle engine?

I have a pretty good first impression. The bypass should facilitate fairly long loiter times, where even a little bit of latent heat would be enough to get the engine started in low pressure mode.  That's something the RL-10 is known for, and it could be seen as a great safety feature for a manned OTV engine.
Blue have OTV on their todo list. Most likely they will use this engine for both OTV and lander along with other common systems. Both vehicles will need handle LH boiloff over a few days.

Which I guess they plan to handle with fuel cell-powered IVF.  I wonder whether a little boiloff H2 figures into the way this engine is designed, as well. Doesn't have to be, but that would be elegant.

Come to that, tying together the fuel cells, the IVF, the boiloff and the BE-7 could be pretty interesting.
I'm not sure what you mean by bypass. Sorry, I not really good with rocket engines language.
With some expander cycle engines like RL10 family and BE-7 there is a bypass valve and line used during prestart to spin up the turbopumps and the ignition process. The BPV is closed upon start.
Oh ok, thanks!

Offline Navier–Stokes

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Re: Blue Origin's BE-7 engine
« Reply #47 on: 10/22/2019 01:00 pm »
https://twitter.com/thesheetztweetz/status/1186621089809649666
Quote
Bezos: Now have 13 minutes of test time on the BE-7 engine.

Offline FutureSpaceTourist

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Re: Blue Origin's BE-7 engine
« Reply #48 on: 01/28/2020 07:07 am »
Quote
AFRL AND BLUE ORIGIN PARTNER ON TEST SITE FOR BE-7 LUNAR LANDER ENGINE DEVELOPMENT

EDWARDS AIR FORCE BASE, Calif. – The Air Force Research Laboratory and Blue Origin are developing a new test facility for the Blue Origin BE-7 lunar lander engine at the AFRL rocket lab here.

Capital improvements, funded by Blue Origin, will allow BE-7 testing in a simulated space-like environment. Planned work includes adding liquid hydrogen (LH2) and liquid oxygen (LOX) propellant capabilities, along with other facility upgrades.

AFRL and Blue Origin signed a 15-year Cooperative Research and Development Agreement Dec. 11, 2019 to develop a test facility for the Blue Origin BE-7 Lunar Lander Engine here. The CRADA was signed by Dr. Shawn Phillips, chief of the Rocket Propulsion Division, and Bob Smith, CEO of Blue Origin.

The BE-7 engine is a new, high performance 10,000 pound-thrust dual-expander cycle engine for in-space applications, including Blue Origin’s Blue Moon lunar lander. The new AFRL test capabilities will support various development, qualification, and production acceptance tests of the BE-7 engine under future Commercial Test Agreements, also to be funded by Blue Origin.

The CRADA focuses on a public-private partnership to create a superior upper stage engine and in-space propulsion testing capability that directly supports near-term national space objectives, and provides enduring infrastructure to support current and future national security and commercial space requirements.

“We are thrilled to partner with the AFRL Aerospace Systems Directorate and their Rocket Propulsion Division at Edwards Air Force Base,” said Eric Blumer, Senior Director for the BE-7 engine program. “Repurposing the infrastructure at the 1-42 test site enables us to accelerate development of the BE-7 engine for our Blue Moon lunar lander. It will play a critical role in Blue Origin’s support of the Artemis program to send women and men to the moon by 2024. Dr. Phillips and his team were very responsive as we defined this unique CRADA.”

“The AFRL team is excited to collaborate with Blue Origin and support the U.S. presence in space,” said Dr. Dan Brown, chief engineer of the AFRL Rocket Lab. “Many of our engineers view this effort as a natural extension of AFRL’s early development of the F-1 engine in the 1950s that ultimately took humans to the moon on the Saturn V.”

“Facility improvements under this public private partnership will open the door for rocket engine testing beyond the BE-7 test campaigns. The new test capability enables the Air Force and future commercial partners to test advanced upper stage engines at relevant altitude conditions.”

The AFRL Rocket Lab at Edwards Air Force Base, California has played a key role in advancing rocket engine technologies for the nation, since 1952.  AFRL has been a prominent player in nearly every liquid rocket engine developed and flown by the United States.

Blue Origin was founded by Jeff Bezos, the founder and CEO of Amazon, in 2000 with the mission to “enable an enduring human presence in space.” The company has focused on developing operationally reusable launch systems and technologies to dramatically lower the cost to access space with greatly increased safety and reliability. Blue Origin has a development facility in Kent, Washington, as well as facilities in Texas, Florida, and Alabama where they test rocket engines and conduct launch operations.

https://afresearchlab.com/news/afrl-and-blue-origin-partner-on-test-site-for-be-7-lunar-lander-engine-development/

First image caption:

Quote
The Altitude facility at Edwards Air Force Base, California, does tactical scale research on next generation rocket motor and engine components, propellant formulations, and subsystems; and high vacuum research on satellite components, subsystems, and systems. Research testing includes solid rocket motor testing at simulated altitudes up to 120,000 feet. The complex has been used for space simulation to validate thrust vector control systems, baseline a standard for solid rocket motor propellants, research extendible nozzle cones, and systems, and research space qualified ignition systems. (Courtesy photo)
« Last Edit: 01/28/2020 07:09 am by FutureSpaceTourist »

Offline Prettz

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Re: Blue Origin's BE-7 engine
« Reply #49 on: 01/28/2020 05:50 pm »
Isn't there already a vacuum facility where the RL10 is tested? Can they not use that?

Offline intelati

Re: Blue Origin's BE-7 engine
« Reply #50 on: 01/28/2020 06:14 pm »
Isn't there already a vacuum facility where the RL10 is tested? Can they not use that?

Repeated future engine  tests??
Starships are meant to fly

Offline russianhalo117

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Re: Blue Origin's BE-7 engine
« Reply #51 on: 01/28/2020 06:54 pm »
Isn't there already a vacuum facility where the RL10 is tested? Can they not use that?
It is assigned to AR which is using it for RL10C-X development and qualification. BO's AFRL TS is adding hydrolox capabilities.

Offline Gliderflyer

Re: Blue Origin's BE-7 engine
« Reply #52 on: 01/28/2020 10:31 pm »
Found a higher resolution version of the BE-7 picture. You can read some of the writing on the oxygen turbopump.
I tried it at home

Offline sunworshipper

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Re: Blue Origin's BE-7 engine
« Reply #53 on: 02/23/2020 05:44 pm »
Quote
...the BE-7 will be tested at an Air Force Research Laboratory (AFRL) facility at Edwards Air Force Base in California.
...
Though testing the BE-7 is the primary purpose of these upgrades, the newly improved facility also will be used to test other pieces of hardware and engines.

"Blue Origin does plan to 'piggyback' parts of the lander that interface to the BE-7 engine to reduce vehicle integration risks and mature the vehicle parts with engine interfaces along with the engine," he said. In other words, some of the pieces that will be tested at this facility, other than the BE-7, will be parts of the lander itself that will join with the lander's engine.
https://www.space.com/blue-origin-opens-rocket-engine-factory-alabama.html?utm_source=twitter&utm_medium=social&utm_campaign=dlvr.it

Quote
The BE-7 engine started hot firing in the summer of 2019 and is currently in test at NASA Marshall Spaceflight Center in partnership with NASA. In total, BE-7 has accrued more than 13 minutes of total test time (more than 780 seconds) on multiple test articles with the most for any single test article being up to 3-minutes of continuous test time.
http://www.parabolicarc.com/2020/02/22/blue-moon-program-fact-sheet/#more-72442

Offline Davidthefat

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Re: Blue Origin's BE-7 engine
« Reply #54 on: 02/27/2020 05:10 pm »
Isn't there already a vacuum facility where the RL10 is tested? Can they not use that?

Isn't the Florida site (where RL-10 is tested) Aerojet Rocketdyne property? Where Stennis (Mississippi) is actually a NASA site where multiple companies use the stands.

Offline Aeneas

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Re: Blue Origin's BE-7 engine
« Reply #55 on: 06/21/2020 08:47 pm »
Isp of 453 s doesn't sound impressive. So the main catch is the deep throttling? Or is there some other advantageous thing to this engine?

Offline ncb1397

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Re: Blue Origin's BE-7 engine
« Reply #56 on: 06/21/2020 09:03 pm »
Isp of 453 s doesn't sound impressive. So the main catch is the deep throttling? Or is there some other advantageous thing to this engine?

There are maybe a couple of engines existing that have better specific impulse. According to wikipedia [1], it essentially is only beat by CE-7.5, RL-10B-2, Vinci and RD-0146D. But clearly it is close to the top of the list if not the top spot.


[1] https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_engines
« Last Edit: 06/21/2020 09:04 pm by ncb1397 »

Offline Aeneas

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Re: Blue Origin's BE-7 engine
« Reply #57 on: 06/21/2020 09:40 pm »

There are maybe a couple of engines existing that have better specific impulse. According to wikipedia [1], it essentially is only beat by CE-7.5, RL-10B-2, Vinci and RD-0146D. But clearly it is close to the top of the list if not the top spot.

[1] https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_engines

True but it's not leading the list. Maybe they have a much better TWR? Yes, it's good to be in the top range but not if the other engines are decades old and you are able to do a greenfield approach.

Offline TrevorMonty

Re: Blue Origin's BE-7 engine
« Reply #58 on: 06/21/2020 11:47 pm »

There are maybe a couple of engines existing that have better specific impulse. According to wikipedia [1], it essentially is only beat by CE-7.5, RL-10B-2, Vinci and RD-0146D. But clearly it is close to the top of the list if not the top spot.

[1] https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_engines

True but it's not leading the list. Maybe they have a much better TWR? Yes, it's good to be in the top range but not if the other engines are decades old and you are able to do a greenfield approach.
Lower dry mass is more important than few seconds ISP. This especially so in case of reuseable lander or OTV where every kg makes a difference.

Offline baldusi

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Re: Blue Origin's BE-7 engine
« Reply #59 on: 06/22/2020 12:17 am »

There are maybe a couple of engines existing that have better specific impulse. According to wikipedia [1], it essentially is only beat by CE-7.5, RL-10B-2, Vinci and RD-0146D. But clearly it is close to the top of the list if not the top spot.

[1] https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_engines

True but it's not leading the list. Maybe they have a much better TWR? Yes, it's good to be in the top range but not if the other engines are decades old and you are able to do a greenfield approach.
Lower dry mass is more important than few seconds ISP. This especially so in case of reuseable lander or OTV where every kg makes a difference.

Price, reliability, throttle range or simply a smaller nozzle than those mentioned above because height is an important factor.

Offline Aeneas

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Re: Blue Origin's BE-7 engine
« Reply #60 on: 06/22/2020 11:06 am »
Do we know the TWR of BE-7?

Offline FutureSpaceTourist

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Re: Blue Origin's BE-7 engine
« Reply #61 on: 09/18/2020 08:56 pm »
twitter.com/thesheetztweetz/status/1307059852729028608

Quote
An infrared image of Blue Origin hot fire testing a BE-7 rocket engine, which will be used for the company's crewed lunar lander, at NASA's Marshall space flight center in June:

https://twitter.com/thesheetztweetz/status/1307060562157862913

Quote
NASA says it worked with Blue Origin "to perform a series of hot-fire tests" on a prototype of the BE-7 engine, which is "additively manufactured" (i.e., 3D-printed).

https://www.nasa.gov/centers/marshall/news/releases/2020/hardware-testing-heats-up-at-marshall-test-laboratory.html

Quote
This summer, Marshall engineers worked with Blue Origin of Kent, Washington, to perform a series of hot-fire tests on Blue Origin’s BE-7 engine thrust chamber assembly prototype. The BE-7 is an additively manufactured engine made to power in-space systems that are under development for various applications. This testing demonstrated features specifically enabled by additive manufacturing to provide high performance, and tested chamber pressures across the full throttle range. The BE-7 will power Blue Origin’s commercial cargo lunar lander system for both government and commercial customers.
« Last Edit: 09/18/2020 08:59 pm by FutureSpaceTourist »

Offline FutureSpaceTourist

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Re: Blue Origin's BE-7 engine
« Reply #62 on: 12/04/2020 12:10 pm »
https://twitter.com/blueorigin/status/1334847142469529601

Quote
The BE-7 is a high-performance, additively manufactured LH2/LOX engine that will power the Blue Origin-led National Team HLS lunar lander. This week's test at @NASA Marshall in Huntsville brings the program’s cumulative test time to 1,245 seconds. #Artemis bit.ly/3oAN4R5

https://www.blueorigin.com/news/be7-engine-testing

Quote
NEWS DEC 4, 2020
BLUE ORIGIN'S BE-7 ENGINE TESTING FURTHER DEMONSTRATES CAPABILITY TO LAND ON THE MOON

HUNTSVILLE, Ala. – Blue Origin’s BE-7 engine program continues its testing at NASA Marshall Space Flight Center. This week, the program kicked off the fourth thrust chamber test series of its high-efficiency engine. The hotfire testing further validates the engine that will power Blue Origin’s National Team Human Landing System (HLS) in support of NASA’s Artemis program.
BE-7 Engine at NASA Marshall

So far in this recent campaign, the thrust chamber was tested for a duration of 20 seconds. This brings the cumulative testing time on the BE-7 thrust chamber to 1,245 seconds. The BE-7 is a high-performance, additively manufactured liquid oxygen/liquid hydrogen lunar landing engine with 10,000 lbf of thrust – throttling down to 2,000 lbf of thrust for a precise landing on the Moon.

“This thrust chamber test measured the ability to extract energy out of the hydrogen and oxygen cooled combustor segments that power the engine’s turbopumps – the key to achieving high engine performance,” said John Vilja, senior vice president, Engines, Blue Origin. “The high specific impulse, deep throttling, and restart capabilities of the BE-7 make it the ideal engine for large lunar payload transport as well as many other in-space applications. Thanks to the NASA Marshall Space Flight Center team for their support in this testing. We value this partnership and are looking forward to more test campaigns with them.”

Within the National Team’s Human Landing System architecture, the BE-7 is used on both the Descent Element and Transfer Element.

“The BE-7, a turbomachinery-based engine using the most efficient propellants, is optimal for deep-space maneuvers and landing on the Moon,” said Brent Sherwood, vice president, Advanced Development Programs, Blue Origin. “Our engine test series is steadily maturing what’s needed to get Americans safely on the lunar surface as soon as possible. We are positioning to use the Moon’s ice resources for rocket propellant, which will make exploration sustainable and open the Moon for commerce.”

Developed privately over several years, the BE-7 is the latest high-performance engine in the Blue Origin family, building upon the demonstrated success of the BE-3 PM hydrogen/oxygen engine that powers the New Shepard vehicle.

Attached photo caption:

Quote
A photo from the fourth thrust chamber test series of the BE-7 engine at NASA Marshall, which lasted 10 seconds.

Attached engine graphic caption:

Quote
BE-7 is an additively manufactured, high-performance, dual-expander cycle engine, generating 40 kN (10,000 lbf) thrust.
« Last Edit: 12/04/2020 12:13 pm by FutureSpaceTourist »

Offline Hog

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Re: Blue Origin's BE-7 engine
« Reply #63 on: 12/04/2020 12:57 pm »
^^^^^^^
Pretty good startup sick goose "honk" at 3 seconds of that video. I dont believe that enough of the shutdown sequence was shown in order to hear if there is a shutdown "honk".
Paul

Offline Seamurda

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Re: Blue Origin's BE-7 engine
« Reply #64 on: 12/07/2020 06:32 pm »

There are maybe a couple of engines existing that have better specific impulse. According to wikipedia [1], it essentially is only beat by CE-7.5, RL-10B-2, Vinci and RD-0146D. But clearly it is close to the top of the list if not the top spot.

[1] https://en.wikipedia.org/wiki/Comparison_of_orbital_rocket_engines

True but it's not leading the list. Maybe they have a much better TWR? Yes, it's good to be in the top range but not if the other engines are decades old and you are able to do a greenfield approach.
Lower dry mass is more important than few seconds ISP. This especially so in case of reuseable lander or OTV where every kg makes a difference.

Price, reliability, throttle range or simply a smaller nozzle than those mentioned above because height is an important factor.

I suspect gimble range might come into it as well, suspect that a lander engine may need to be able to gimble further and faster than an OTV engine this would limit your range of expansion ratios.

TWR makes more of a difference on a lander engine vs an OTV as well, all things being equal on an OTV you can reduce the thrust to lower engine weight and trade for a large nozzle.

ISP basically scales by fuel type, expansion ratio, cycle type, combustion efficiency and chamber pressure in about that order. As a closed cycle I'd expect the BE-7 to have about the same ISP as an RL-10 for a given expansion ratio with a slight advantage due to getting rid of a gearbox.

For reference in NASAs 1980's OTV study a dual expander engine was proposed with an ISP of 480+ with a 650-1 expansion ratio which would indicate where this engine may be able to go one day.

Offline GWH

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Re: Blue Origin's BE-7 engine
« Reply #65 on: 12/09/2020 02:18 pm »
Close up view of the thrust chamber on the test stand from Blue's latest HLS video @ 4:22:
« Last Edit: 12/10/2020 02:28 am by GWH »

Offline Gliderflyer

Re: Blue Origin's BE-7 engine
« Reply #66 on: 12/10/2020 12:08 pm »
All the BE-7 CAD (and the mockup) have the LOX regen section as part of the nozzle. I guess they can't run that at sea level because the one at Marshall appears to have it above the normal chamber section.
I tried it at home

Offline kfsorensen

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Re: Blue Origin's BE-7 engine
« Reply #67 on: 02/10/2021 06:20 pm »
WANTED INFO: Biggest unknown piece of information for this engine is the O/F (oxidizer to fuel) ratio. Will be added here if found.

Did anyone ever find out (or deduce) the mixture ratio of this engine?
Doesn't seem like it should be any big secret.  If it's anything like other LH2/LOX engines it will be somewhere around 5.5 to 6.0.

Offline Hog

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Re: Blue Origin's BE-7 engine
« Reply #68 on: 02/10/2021 07:13 pm »
WANTED INFO: Biggest unknown piece of information for this engine is the O/F (oxidizer to fuel) ratio. Will be added here if found.

Did anyone ever find out (or deduce) the mixture ratio of this engine?
Doesn't seem like it should be any big secret.  If it's anything like other LH2/LOX engines it will be somewhere around 5.5 to 6.0.
RL10, also being an expander cycle-hydrolox engine is around 5.88:1, so I'd guess your 5.5-6.0 MR(Mixture Ratio) sound credible..

IIRC The right engine of STS-93 with its thrust limiting nozzle leak, added more oxidizer to the mix and ran it at 6.03:1, which led to a "Lox Low Level Cut-off" resulting in a 0.15 foot per second underspeed of the vehicle. 

The deep-throttling capability of the BE-7  will be exciting and very useful.
« Last Edit: 02/10/2021 07:16 pm by Hog »
Paul

Offline WormPicker959

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Re: Blue Origin's BE-7 engine
« Reply #69 on: 02/26/2021 07:30 pm »
https://twitter.com/blueorigin/status/1334847142469529601

Quote
The BE-7 is a high-performance, additively manufactured LH2/LOX engine that will power the Blue Origin-led National Team HLS lunar lander. This week's test at @NASA Marshall in Huntsville brings the program’s cumulative test time to 1,245 seconds. #Artemis bit.ly/3oAN4R5

https://www.blueorigin.com/news/be7-engine-testing

Quote
NEWS DEC 4, 2020
BLUE ORIGIN'S BE-7 ENGINE TESTING FURTHER DEMONSTRATES CAPABILITY TO LAND ON THE MOON

HUNTSVILLE, Ala. – Blue Origin’s BE-7 engine program continues its testing at NASA Marshall Space Flight Center. This week, the program kicked off the fourth thrust chamber test series of its high-efficiency engine. The hotfire testing further validates the engine that will power Blue Origin’s National Team Human Landing System (HLS) in support of NASA’s Artemis program.
BE-7 Engine at NASA Marshall

So far in this recent campaign, the thrust chamber was tested for a duration of 20 seconds. This brings the cumulative testing time on the BE-7 thrust chamber to 1,245 seconds. The BE-7 is a high-performance, additively manufactured liquid oxygen/liquid hydrogen lunar landing engine with 10,000 lbf of thrust – throttling down to 2,000 lbf of thrust for a precise landing on the Moon.

“This thrust chamber test measured the ability to extract energy out of the hydrogen and oxygen cooled combustor segments that power the engine’s turbopumps – the key to achieving high engine performance,” said John Vilja, senior vice president, Engines, Blue Origin. “The high specific impulse, deep throttling, and restart capabilities of the BE-7 make it the ideal engine for large lunar payload transport as well as many other in-space applications. Thanks to the NASA Marshall Space Flight Center team for their support in this testing. We value this partnership and are looking forward to more test campaigns with them.”

Within the National Team’s Human Landing System architecture, the BE-7 is used on both the Descent Element and Transfer Element.

“The BE-7, a turbomachinery-based engine using the most efficient propellants, is optimal for deep-space maneuvers and landing on the Moon,” said Brent Sherwood, vice president, Advanced Development Programs, Blue Origin. “Our engine test series is steadily maturing what’s needed to get Americans safely on the lunar surface as soon as possible. We are positioning to use the Moon’s ice resources for rocket propellant, which will make exploration sustainable and open the Moon for commerce.”

Developed privately over several years, the BE-7 is the latest high-performance engine in the Blue Origin family, building upon the demonstrated success of the BE-3 PM hydrogen/oxygen engine that powers the New Shepard vehicle.

Attached photo caption:

Quote
A photo from the fourth thrust chamber test series of the BE-7 engine at NASA Marshall, which lasted 10 seconds.

Attached engine graphic caption:

Quote
BE-7 is an additively manufactured, high-performance, dual-expander cycle engine, generating 40 kN (10,000 lbf) thrust.

Would somebody smarter than me explain why the flame here is so blue/yellow? I was under the impression that Hydrolox engines tend to have nearly transparent blue exhaust? I suppose it must be the glow from kicked up dust?

Offline Gliderflyer

Re: Blue Origin's BE-7 engine
« Reply #70 on: 02/26/2021 11:56 pm »
Would somebody smarter than me explain why the flame here is so blue/yellow? I was under the impression that Hydrolox engines tend to have nearly transparent blue exhaust? I suppose it must be the glow from kicked up dust?

Because it burns mostly clear, small impurities can have large effects on the color. I don't know the exact spec of hydrogen that Marshall uses, but I have seen some very orange hydrogen engine pictures before. A few parts per million of stuff can change the color. The camera settings at night can also play a part.
« Last Edit: 02/26/2021 11:57 pm by Gliderflyer »
I tried it at home

Offline Gliderflyer

Re: Blue Origin's BE-7 engine
« Reply #71 on: 03/26/2022 01:31 am »
Looks like there is a new render of BE-7 in the latest Blue Origin video. Lot less spaghetti looking. Also looks like they are going with a throat gimbal.
I tried it at home

Offline Gliderflyer

Re: Blue Origin's BE-7 engine
« Reply #72 on: 04/02/2022 01:30 am »
In the NS-20 webcast (around T-54:22), there was a hot fire video from 2/23/2022 of BE-7 at NASA's TS116 stand. It looks like the TCA is still running in pressure fed mode without pumps installed.
I tried it at home

Offline FutureSpaceTourist

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Re: Blue Origin's BE-7 engine
« Reply #73 on: 05/18/2022 08:44 pm »
https://twitter.com/blueorigin/status/1527026736688353280

Quote
Earlier this year, Blue Origin’s #BE7 lunar lander engines program completed another successful Thrust Chamber Assembly hotfire test campaign at @NASA_Marshall. To date, the campaign has completed a total of 92 tests for 3,347 cumulative seconds of hotfire.

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Re: Blue Origin's BE-7 engine
« Reply #74 on: 03/28/2023 05:01 pm »
twitter.com/blueorigin/status/1640760790285254674

Quote
Last week, our BE-7 team conducted another successful Thrust Chamber Assembly (TCA) test at NASA Marshall Space Flight Center Test Stand 116. Our tests on an upgraded TCA bring our cumulative test time to more than 4000 seconds, and we are on track in our engine development path.

https://twitter.com/blueorigin/status/1640760794240499712

Quote
This was a self-funded test as part of our campaign to advance our lunar capabilities, and we’re grateful for our @NASA_Marshall partners.
« Last Edit: 03/28/2023 05:01 pm by FutureSpaceTourist »

Online Robert_the_Doll

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Re: Blue Origin's BE-7 engine
« Reply #75 on: 03/28/2023 06:23 pm »
Video also available on YouTube and Facebook.


Offline Comga

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Re: Blue Origin's BE-7 engine
« Reply #76 on: 03/28/2023 07:06 pm »
Looks like there is a new render of BE-7 in the latest Blue Origin video.
Lot less spaghetti looking.
Also looks like they are going with a throat gimbal.

A search for “throat gimbaled rocket engine” turned up a fascinating discussion of the Lunar Module Descent Engine at enginehistory.org.
Its gimbal mount ring, which looks almost square, appears quite similar to the gimbal attach ring on the BE-7 render.

The page also includes the following statement:
Quote
TRW developed the LMDE on an extremely compressed schedule. Fortunately, there was plenty of hardware and a test-as-you-go philosophy that helped identify component problems early, before they could impact subassemblies and assemblies. Testing, of course, continued at the subassembly and assembly level.


Cumulative test time was 163,957 seconds.

It looks like Blue adopted some of project lead Jerry Elevrum’s concepts but not others. ;)
« Last Edit: 03/28/2023 07:11 pm by Comga »
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline GWH

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Re: Blue Origin's BE-7 engine
« Reply #77 on: 03/29/2023 02:07 am »
An excellent post on reddit points out a tweet from late 2020. Back then they were at 1245 seconds of runtime.

https://twitter.com/blueorigin/status/1334847142469529601?t=ZoNwNGqISg-PL3-G94JnPw&


2.5 years to perform an additional 2755 seconds of run time. An average 92 seconds of testing per month, or 3 seconds per day.

Certainly NOT hardware rich. Which seems endemic to all their engine programs.

Offline GWH

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Re: Blue Origin's BE-7 engine
« Reply #78 on: 03/29/2023 02:20 am »
Tom Mueller throwing shade:
https://twitter.com/lrocket/status/1640825353278218241?t=_dm9cYu1VuEAUBFWSbczJg&

I thought it was odd how the exhaust looks like they're running methalox, but am not knowledgeable myself to comment.

Offline wannamoonbase

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Re: Blue Origin's BE-7 engine
« Reply #79 on: 03/29/2023 09:13 pm »
2.5 years to perform an additional 2755 seconds of run time. An average 92 seconds of testing per month, or 3 seconds per day.

Certainly NOT hardware rich. Which seems endemic to all their engine programs.

One would have thought that they might have learned from BE-4, but here we are again.

Pretty unimpressive.
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Re: Blue Origin's BE-7 engine
« Reply #80 on: 03/29/2023 09:29 pm »
2.5 years to perform an additional 2755 seconds of run time. An average 92 seconds of testing per month, or 3 seconds per day.

Certainly NOT hardware rich. Which seems endemic to all their engine programs.

For scale, according to the NSF counter SpaceX has performed 447s of Raptor testing *today* and it's only 4:28 PM. No wonder Tom Mueller thinks their film cooling isn't quite dialled in.
Which booster has the most soot? SpaceX booster launch history! (discussion)

Offline russianhalo117

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Re: Blue Origin's BE-7 engine
« Reply #81 on: 03/29/2023 10:50 pm »
2.5 years to perform an additional 2755 seconds of run time. An average 92 seconds of testing per month, or 3 seconds per day.

Certainly NOT hardware rich. Which seems endemic to all their engine programs.

One would have thought that they might have learned from BE-4, but here we are again.

Pretty unimpressive.
It is their first nearly entirely 3D printed additive manufactured engine. A few friends say they are using rapid iteration design and test methodology. We are only seeing the iterations they choose to show, which are often ones where they have reached a major iteration cycle milestone to test full up assembled component assemblies where in this case the marrying of the engine powerhead assembly with their newest iteration of their engine thrust chamber assembly.

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Re: Blue Origin's BE-7 engine
« Reply #82 on: 03/30/2023 10:25 am »
Tom Mueller throwing shade:
https://twitter.com/lrocket/status/1640825353278218241?t=_dm9cYu1VuEAUBFWSbczJg&

I thought it was odd how the exhaust looks like they're running methalox, but am not knowledgeable myself to comment.

Oh man, that is ironic: BE-7 running with TOO MUCH boundary layer cooling, whereas NS-23 failed because the BE-3PM engine was running with NOT ENOUGH boundary layer cooling.
« Last Edit: 03/30/2023 12:54 pm by woods170 »

Offline Eric Hedman

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Re: Blue Origin's BE-7 engine
« Reply #83 on: 03/30/2023 02:57 pm »
Oh man, that is ironic: BE-7 running with TOO MUCH boundary layer cooling, whereas NS-23 failed because the BE-3PM engine was running with NOT ENOUGH boundary layer cooling.
That's just how engineering works to find the right trade offs to make something work reliably.  They are still learning and will get it right for both engines.

Offline Robotbeat

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Re: Blue Origin's BE-7 engine
« Reply #84 on: 03/30/2023 03:19 pm »
Too much film cooling is a problem largely for efficiency. If you have enough margin, go ahead and use a ton of film cooling.
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Offline Comga

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Re: Blue Origin's BE-7 engine
« Reply #85 on: 03/30/2023 09:40 pm »
2.5 years to perform an additional 2755 seconds of run time. An average 92 seconds of testing per month, or 3 seconds per day.

Certainly NOT hardware rich. Which seems endemic to all their engine programs.

One would have thought that they might have learned from BE-4, but here we are again.

Pretty unimpressive.

It is their first nearly entirely 3D printed additive manufactured engine. A few friends say they are using rapid iteration design and test methodology. We are only seeing the iterations they choose to show, which are often ones where they have reached a major iteration cycle milestone to test full up assembled component assemblies where in this case the marrying of the engine powerhead assembly with their newest iteration of their engine thrust chamber assembly.

That sounds exessively generous to Blue
We are not talking about the test firings they show publicly.
It's Blue's own statements about cumulatve test fire time:
  4 Dec 2020     1245 sec
18 May 2022     3347 sec  (4.0 sec/day)
28 Mar 2023   >4000 sec  (2.1 sec/day)

By definition Blue is not "using rapid iteration design and test methodology".
That method got the LMDE almost 164,000 seconds of test firings in a few years, not 4,000.
Blue has a half century of improved technology, and non-toxic propellants, and the vaunted 3D printing, to go ten times faster, not 100 times slower.

And it is NOT "just how engineering works" to be testing new conditions in an operational flight, with an engine that completed it's acceptance testing eight years ago.
The time for trial and error, pushing the boundaries, is on the test stand.
« Last Edit: 03/31/2023 06:08 pm by Comga »
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline russianhalo117

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Re: Blue Origin's BE-7 engine
« Reply #86 on: 03/30/2023 09:59 pm »
2.5 years to perform an additional 2755 seconds of run time. An average 92 seconds of testing per month, or 3 seconds per day.

Certainly NOT hardware rich. Which seems endemic to all their engine programs.

One would have thought that they might have learned from BE-4, but here we are again.

Pretty unimpressive.

It is their first nearly entirely 3D printed additive manufactured engine. A few friends say they are using rapid iteration design and test methodology. We are only seeing the iterations they choose to show, which are often ones where they have reached a major iteration cycle milestone to test full up assembled component assemblies where in this case the marrying of the engine powerhead assembly with their newest iteration of their engine thrust chamber assembly.

That sounds exessively generous to Blue
We are not talking about the test firings they show publicly.
It's Blue's own statements about cumulatve test fire time:
  4 Dec 2020     1245 sec
18 May 2022     3347 sec  (4.0 sec/day)
28 Mar 2023   >4000 sec  (2.1 sec/day)

By definition Blue is not "using rapid iteration design and test methodology".
That method got the LMDE almost 164,000 seconds of test firings in a few years, not 4,000.
Blue has a half century of improved technology, and non-toxic propellants, and the vaulted 3D printing, to go ten times faster, not 100 times slower.

And it is NOT "just how engineering works" to be testing new conditions in an operational flight, with an engine that completed it's acceptance testing eight years ago.
The time for trial and error, pushing the boundaries, is on the test stand.

Yes you are correct. Don't shoot the messenger. Also some firms do not count all firing tests in their totals. BO seems per my observations to only count total duration time for major iteration tests that end with a positive result. They seem to be very selective in what is public.

Offline butters

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Re: Blue Origin's BE-7 engine
« Reply #87 on: 03/30/2023 10:16 pm »
Oh man, that is ironic: BE-7 running with TOO MUCH boundary layer cooling, whereas NS-23 failed because the BE-3PM engine was running with NOT ENOUGH boundary layer cooling.

As long as they don't verify BE-7's design using more film cooling in ground tests they use in flight operations. If that's what happened with BE-3, and they repeat it with BE-7, that's definitely not a good look. They gotta fly with the cooling they tested. Especially if this is going to be human-rated lunar ascent propulsion.

Offline whitelancer64

Re: Blue Origin's BE-7 engine
« Reply #88 on: 03/30/2023 10:25 pm »
2.5 years to perform an additional 2755 seconds of run time. An average 92 seconds of testing per month, or 3 seconds per day.

Certainly NOT hardware rich. Which seems endemic to all their engine programs.

One would have thought that they might have learned from BE-4, but here we are again.

Pretty unimpressive.

It is their first nearly entirely 3D printed additive manufactured engine. A few friends say they are using rapid iteration design and test methodology. We are only seeing the iterations they choose to show, which are often ones where they have reached a major iteration cycle milestone to test full up assembled component assemblies where in this case the marrying of the engine powerhead assembly with their newest iteration of their engine thrust chamber assembly.

That sounds exessively generous to Blue
We are not talking about the test firings they show publicly.
It's Blue's own statements about cumulatve test fire time:
  4 Dec 2020     1245 sec
18 May 2022     3347 sec  (4.0 sec/day)
28 Mar 2023   >4000 sec  (2.1 sec/day)

By definition Blue is not "using rapid iteration design and test methodology".
That method got the LMDE almost 164,000 seconds of test firings in a few years, not 4,000.
Blue has a half century of improved technology, and non-toxic propellants, and the vaulted 3D printing, to go ten times faster, not 100 times slower.

And it is NOT "just how engineering works" to be testing new conditions in an operational flight, with an engine that completed it's acceptance testing eight years ago.
The time for trial and error, pushing the boundaries, is on the test stand.

There's lots of component development, iteration, and testing that can be done that wouldn't necessarily result in hot fire test time.

And I'm not sure anything would compare well with the LMDE's hot fire test time. They tested the everloving bejesus out of that design because they had to, it HAD to work, and they didn't have any of the advantages offered by modern design tools.
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Offline JCRM

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Re: Blue Origin's BE-7 engine
« Reply #89 on: 03/31/2023 08:02 am »
with modern data acquisition a few seconds of test can generate months of work to understand the differences between the model and reality, and how to update the model.

What works on a test stand may not work in flight -- it's *really* hard to simulate flight conditions.

Personally, I thought Mueller's comment was a joke - he's not involved in the engine design, so doesn't know what the requirements are

Offline RDMM2081

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Re: Blue Origin's BE-7 engine
« Reply #90 on: 03/31/2023 04:23 pm »
FWIW (Almost nothing, IANARS), I interpreted Tom's statement as mostly a joke, but also "as one who knows a little something about rocket engines I see a "lot" of film cooling which in the context of lost ISP is probably outweighing the corresponding TWR losses you would suffer by just increasing the mass of the cooling system or other pressure bearing systems of this engine".

That kind of "too much film cooling" should be observable to an expert in the field I think?

Offline LouScheffer

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Re: Blue Origin's BE-7 engine
« Reply #91 on: 03/31/2023 05:03 pm »
That sounds exessively generous to Blue
We are not talking about the test firings they show publicly.
It's Blue's own statements about cumulatve test fire time:
  4 Dec 2020     1245 sec
18 May 2022     3347 sec  (4.0 sec/day)
28 Mar 2023   >4000 sec  (2.1 sec/day)

By definition Blue is not "using rapid iteration design and test methodology".
That method got the LMDE almost 164,000 seconds of test firings in a few years, not 4,000.
Blue has a half century of improved technology, and non-toxic propellants, and the vaulted 3D printing, to go ten times faster, not 100 times slower.
And I'm not sure anything would compare well with the LMDE's hot fire test time. They tested the everloving bejesus out of that design because they had to, it HAD to work, and they didn't have any of the advantages offered by modern design tools.
164,000 seconds of test is 449 seconds per day for a year.  SpaceX often (but not always) get this much testing in a day, and have been testing for well over a year.  They will surely (if they have not already) reach LDME numbers.

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Re: Blue Origin's BE-7 engine
« Reply #92 on: 03/31/2023 05:29 pm »
Oh man, that is ironic: BE-7 running with TOO MUCH boundary layer cooling, whereas NS-23 failed because the BE-3PM engine was running with NOT ENOUGH boundary layer cooling.
That's just how engineering works to find the right trade offs to make something work reliably.  They are still learning and will get it right for both engines.

Disagree. New Shepard is supposed to be an operational vehicle with a mature and thoroughly understood engine. Particularly considering the fact that Blue has begun flying people on New Shepard.

Offline woods170

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Re: Blue Origin's BE-7 engine
« Reply #93 on: 03/31/2023 05:38 pm »
FWIW (Almost nothing, IANARS), I interpreted Tom's statement as mostly a joke, but also "as one who knows a little something about rocket engines I see a "lot" of film cooling which in the context of lost ISP is probably outweighing the corresponding TWR losses you would suffer by just increasing the mass of the cooling system or other pressure bearing systems of this engine".

That kind of "too much film cooling" should be observable to an expert in the field I think?

Very much in fact. Tom Mueller is one of the biggest living experts on rocket engines.


Offline RDMM2081

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Re: Blue Origin's BE-7 engine
« Reply #94 on: 03/31/2023 07:52 pm »
FWIW (Almost nothing, IANARS), I interpreted Tom's statement as mostly a joke, but also "as one who knows a little something about rocket engines I see a "lot" of film cooling which in the context of lost ISP is probably outweighing the corresponding TWR losses you would suffer by just increasing the mass of the cooling system or other pressure bearing systems of this engine".

That kind of "too much film cooling" should be observable to an expert in the field I think?

Very much in fact. Tom Mueller is one of the biggest living experts on rocket engines.

I apologize if from my context it was unclear I was asserting that Tom Mueller is in fact one of those experts on rocket engines.

Online Robert_the_Doll

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Re: Blue Origin's BE-7 engine
« Reply #95 on: 03/31/2023 08:34 pm »
Oh man, that is ironic: BE-7 running with TOO MUCH boundary layer cooling, whereas NS-23 failed because the BE-3PM engine was running with NOT ENOUGH boundary layer cooling.
That's just how engineering works to find the right trade offs to make something work reliably.  They are still learning and will get it right for both engines.

Disagree. New Shepard is supposed to be an operational vehicle with a mature and thoroughly understood engine. Particularly considering the fact that Blue has begun flying people on New Shepard.

Unfortunately, not everything can be tested for on the ground. At some point a rocket must fly. What no one has really spoken of is that there appears to be enough of a difference between the NS3 and 4 Propulsion Modules that allowed one to fly eight missions in less than a year without any discernible issue and without its engine being swapped out between flights. The other in contrast, flew only a couple times per year and after seven years on its ninth flight it suffered this problem. 

Offline JCRM

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Re: Blue Origin's BE-7 engine
« Reply #96 on: 03/31/2023 10:23 pm »
FWIW (Almost nothing, IANARS), I interpreted Tom's statement as mostly a joke, but also "as one who knows a little something about rocket engines I see a "lot" of film cooling which in the context of lost ISP is probably outweighing the corresponding TWR losses you would suffer by just increasing the mass of the cooling system or other pressure bearing systems of this engine".

That kind of "too much film cooling" should be observable to an expert in the field I think?

Maybe... but I still think it was a joke about the water and referencing the lost NS -- the alternative being that is was so gratuitously too much that it could be diagnosed from a video, without knowing the requirements whilst Blue's engineers with all their detailed knowledge and instrumentation didn't know it was too much.

IANARS, but I know a thing or two about dad jokes.

« Last Edit: 03/31/2023 10:29 pm by JCRM »

Offline whitelancer64

Re: Blue Origin's BE-7 engine
« Reply #97 on: 04/01/2023 04:27 am »
That sounds exessively generous to Blue
We are not talking about the test firings they show publicly.
It's Blue's own statements about cumulatve test fire time:
  4 Dec 2020     1245 sec
18 May 2022     3347 sec  (4.0 sec/day)
28 Mar 2023   >4000 sec  (2.1 sec/day)

By definition Blue is not "using rapid iteration design and test methodology".
That method got the LMDE almost 164,000 seconds of test firings in a few years, not 4,000.
Blue has a half century of improved technology, and non-toxic propellants, and the vaulted 3D printing, to go ten times faster, not 100 times slower.
And I'm not sure anything would compare well with the LMDE's hot fire test time. They tested the everloving bejesus out of that design because they had to, it HAD to work, and they didn't have any of the advantages offered by modern design tools.
164,000 seconds of test is 449 seconds per day for a year.  SpaceX often (but not always) get this much testing in a day, and have been testing for well over a year.  They will surely (if they have not already) reach LDME numbers.

Not during development.
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Offline LouScheffer

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Re: Blue Origin's BE-7 engine
« Reply #98 on: 04/01/2023 12:10 pm »
By definition Blue is not "using rapid iteration design and test methodology".
That method got the LMDE almost 164,000 seconds of test firings in a few years, not 4,000.
And I'm not sure anything would compare well with the LMDE's hot fire test time. They tested the everloving bejesus out of that design because they had to, it HAD to work, and they didn't have any of the advantages offered by modern design tools.
164,000 seconds of test is 449 seconds per day for a year.  SpaceX often (but not always) get this much testing in a day, and have been testing for well over a year.  They will surely (if they have not already) reach LDME numbers.
Not during development.
I think even during development.  The only tests that are not part of development are the acceptance tests for completed engines.  Assuming this is a full duration burn, and they've built 200 engines, that's only 28,000 test seconds.  And we know Raptor is still under development - Musk recently tweeted that recent tests were concentrating on expanding the start box to include "warm" propellants.

Offline Craigles

Re: Blue Origin's BE-7 engine
« Reply #99 on: 04/10/2023 03:57 am »
Looks like there is a new render of BE-7 in the latest Blue Origin video.
Lot less spaghetti looking.
Also looks like they are going with a throat gimbal.

A search for “throat gimbaled rocket engine” turned up a fascinating discussion of the Lunar Module Descent Engine at enginehistory.org.
Its gimbal mount ring, which looks almost square, appears quite similar to the gimbal attach ring on the BE-7 render.

The page also includes the following statement:
Quote
TRW developed the LMDE on an extremely compressed schedule. Fortunately, there was plenty of hardware and a test-as-you-go philosophy that helped identify component problems early, before they could impact subassemblies and assemblies. Testing, of course, continued at the subassembly and assembly level.


Cumulative test time was 163,957 seconds.

It looks like Blue adopted some of project lead Jerry Elevrum’s concepts but not others. ;)
If the BE-7 is throat gimballed, does that imply that the nozzle won't have plumbing for regenerative cooling or for expander cycle heat exchange?
I'd rather be here now

Offline trimeta

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Re: Blue Origin's BE-7 engine
« Reply #100 on: 04/19/2023 12:46 am »
Short Twitter thread about BE-7 components.

https://twitter.com/blueorigin/status/1648473696519200772

Quote
First and second stage fuel turbopump impellers for the BE-7 engine shown before final machining. Each BE-7 hydrogen pump uses two of these shrouded titanium impellers.

Quote
Pictured here are additively manufactured single piece BE-7 injectors where hydrogen and oxygen are injected into the main combustion chamber. Export restrictions constrain us from showing the business end of the injector.

https://twitter.com/blueorigin/status/1648473704077357056

Quote
Pictured here are nickel-based super alloy jackets that get vacuum-brazed onto the BE-7 slotted copper liner to complete the regen nozzle. The cone shape is hydraulically formed into the final nozzle contour using the tooling shown.

There were two other threads pertaining to Blue Moon, but I posted about them in the Blue Moon thread.

Offline Rakietwawka2021

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Re: Blue Origin's BE-7 engine
« Reply #101 on: 04/19/2023 05:04 am »
Can someone explain me what are the purpose of these nozzles?

Offline JCRM

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Re: Blue Origin's BE-7 engine
« Reply #102 on: 04/19/2023 08:08 am »
Can someone explain me what are the purpose of these nozzles?
could you explain what it is you don't understand?

To extract more thrust from the engine by controlling the expansion of the exhaust (that's what nozzles do), while simultaneously harvesting heat from the exhaust to drive the turbomachinery that fuels the engine (that's the regen part)

Offline Asteroza

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Re: Blue Origin's BE-7 engine
« Reply #103 on: 04/21/2023 12:26 am »
Can someone explain me what are the purpose of these nozzles?

These particular nozzles appear to be in various stages of manufacturing, from a simple initial conic form in the middle, to a more bell shape towards the right, then some shaping of the throat. The large blue objects on the left appear to shaping molds of some kind?

Offline Vahe231991

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Re: Blue Origin's BE-7 engine
« Reply #104 on: 05/19/2023 11:52 pm »
Given that Blue Origin today was awarded the NASA astronaut moon lander contract for Artemis missions late in the 2020s, a few of the first fabricated BE-7s could be earmarked for the first Blue Origin HLS vehicle.

Online Robert_the_Doll

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Re: Blue Origin's BE-7 engine
« Reply #105 on: 05/20/2023 02:08 am »
It is more likely that what we are seeing here will be earmarked for a very rapid full-scale engine testing and qualification effort. It is good to see that BE-7 bell nozzles, impellers, combustion chambers, etc. are being turned out so quickly and in such numbers. Although that is not surprising given how much smaller in size they are compared to even the BE-3 PM and U.

Offline sevenperforce

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Re: Blue Origin's BE-7 engine
« Reply #106 on: 05/24/2023 03:28 pm »
Is there any progress toward reverse-engineering a flow diagram for the BE-7?

Are we sure it is a closed dual expander and doesn't have a bleed anywhere?

Looks like there is a new render of BE-7 in the latest Blue Origin video.
Lot less spaghetti looking.
Also looks like they are going with a throat gimbal.

A search for “throat gimbaled rocket engine” turned up a fascinating discussion of the Lunar Module Descent Engine at enginehistory.org.
Its gimbal mount ring, which looks almost square, appears quite similar to the gimbal attach ring on the BE-7 render.

The page also includes the following statement:
Quote
TRW developed the LMDE on an extremely compressed schedule. Fortunately, there was plenty of hardware and a test-as-you-go philosophy that helped identify component problems early, before they could impact subassemblies and assemblies. Testing, of course, continued at the subassembly and assembly level.


Cumulative test time was 163,957 seconds.

It looks like Blue adopted some of project lead Jerry Elevrum’s concepts but not others. ;)
If the BE-7 is throat gimballed, does that imply that the nozzle won't have plumbing for regenerative cooling or for expander cycle heat exchange?
The nozzle extension appears to be carbon-carbon which suggests radiative cooling but the metal stamped bits in some of the recent images look like they could be going a different direction.

Online Robert_the_Doll

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Re: Blue Origin's BE-7 engine
« Reply #107 on: 05/24/2023 05:44 pm »
All indications are that it remains a duel expander cycle engine, as there has been no changes at the Blue Origin website:

https://www.blueorigin.com/engines/be-7/

"BE-7 is an additively manufactured, high-performance, dual-expander cycle engine, generating 44.5 kN (10,000 lbf) thrust.

We are maturing the design, manufacturing hardware and have begun hotfiring the engine."


There are diagrams of this cycle, such as this Aerojet one:


Offline sevenperforce

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Re: Blue Origin's BE-7 engine
« Reply #108 on: 05/24/2023 05:53 pm »
Found a higher resolution version of the BE-7 picture. You can read some of the writing on the oxygen turbopump.
What I can read in your image:

OXYGEN TURBINE IN (right side of oxygen turbopump)
OX KICK OUT (vertical pipe coming down out of the center of the oxygen turbopump)
OXYGEN PUMP IN (rim on flat cap on left of oxygen turbopump without piping)

Seems like a weird label. Is that flat cap supposed to be where the plumbing enters from the tank? What does "OX KICK" suggest in this context -- a separate booster pump?

All indications are that it remains a duel expander cycle engine, as there has been no changes at the Blue Origin website:

https://www.blueorigin.com/engines/be-7/

"BE-7 is an additively manufactured, high-performance, dual-expander cycle engine, generating 44.5 kN (10,000 lbf) thrust.

We are maturing the design, manufacturing hardware and have begun hotfiring the engine."

Yeah, I'm reasonably familiar with the cycles for a dual expander design, but I'm curious if anyone has sleuthed through the existing images to figure out what the various parts of the plumbing actually do.
« Last Edit: 05/24/2023 06:01 pm by sevenperforce »

Offline Starshipdown

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Re: Blue Origin's BE-7 engine
« Reply #109 on: 05/24/2023 06:37 pm »
Is there any progress toward reverse-engineering a flow diagram for the BE-7?

Are we sure it is a closed dual expander and doesn't have a bleed anywhere?

Looks like there is a new render of BE-7 in the latest Blue Origin video.
Lot less spaghetti looking.
Also looks like they are going with a throat gimbal.

A search for “throat gimbaled rocket engine” turned up a fascinating discussion of the Lunar Module Descent Engine at enginehistory.org.
Its gimbal mount ring, which looks almost square, appears quite similar to the gimbal attach ring on the BE-7 render.

The page also includes the following statement:
Quote
TRW developed the LMDE on an extremely compressed schedule. Fortunately, there was plenty of hardware and a test-as-you-go philosophy that helped identify component problems early, before they could impact subassemblies and assemblies. Testing, of course, continued at the subassembly and assembly level.


Cumulative test time was 163,957 seconds.

It looks like Blue adopted some of project lead Jerry Elevrum’s concepts but not others. ;)
If the BE-7 is throat gimballed, does that imply that the nozzle won't have plumbing for regenerative cooling or for expander cycle heat exchange?
The nozzle extension appears to be carbon-carbon which suggests radiative cooling but the metal stamped bits in some of the recent images look like they could be going a different direction.

They didn't change anything, they've gone with a regenerative nozzle, per their tweet, which you can read above a few posts back:

Quote
"Pictured here are nickel-based super alloy jackets that get vacuum-brazed onto the BE-7 slotted copper liner to complete the regen nozzle. The cone shape is hydraulically formed into the final nozzle contour using the tooling shown."

Radiative cooling wouldn't work for an engine buried inside the center of or under the cladding of the exterior of the crew module section.


Offline sevenperforce

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Re: Blue Origin's BE-7 engine
« Reply #110 on: 05/24/2023 06:58 pm »
If the BE-7 is throat gimballed, does that imply that the nozzle won't have plumbing for regenerative cooling or for expander cycle heat exchange?
The nozzle extension appears to be carbon-carbon which suggests radiative cooling but the metal stamped bits in some of the recent images look like they could be going a different direction.

They didn't change anything, they've gone with a regenerative nozzle, per their tweet, which you can read above a few posts back:

Quote
"Pictured here are nickel-based super alloy jackets that get vacuum-brazed onto the BE-7 slotted copper liner to complete the regen nozzle. The cone shape is hydraulically formed into the final nozzle contour using the tooling shown."

Radiative cooling wouldn't work for an engine buried inside the center of or under the cladding of the exterior of the crew module section.
Ah, that makes sense.

What's curious, to me, is that the diagram on their website clearly labels the turbopump with the downward-pointing central exit tube as the hydrogen turbopump, but the super-clear image from a few pages back labels that as the oxygen turbopump:



And that's clearly a view from the same side (the rotated version shows that the turbopump on the opposite side had the output tubing pointing up, now down):



All this may be academic given the apparent new engine design, but it's still an odd mistake, if it's a mistake.
« Last Edit: 05/24/2023 06:59 pm by sevenperforce »

Offline whitelancer64

Re: Blue Origin's BE-7 engine
« Reply #111 on: 05/25/2023 05:22 pm »
If the BE-7 is throat gimballed, does that imply that the nozzle won't have plumbing for regenerative cooling or for expander cycle heat exchange?
The nozzle extension appears to be carbon-carbon which suggests radiative cooling but the metal stamped bits in some of the recent images look like they could be going a different direction.

They didn't change anything, they've gone with a regenerative nozzle, per their tweet, which you can read above a few posts back:

Quote
"Pictured here are nickel-based super alloy jackets that get vacuum-brazed onto the BE-7 slotted copper liner to complete the regen nozzle. The cone shape is hydraulically formed into the final nozzle contour using the tooling shown."

Radiative cooling wouldn't work for an engine buried inside the center of or under the cladding of the exterior of the crew module section.
Ah, that makes sense.

What's curious, to me, is that the diagram on their website clearly labels the turbopump with the downward-pointing central exit tube as the hydrogen turbopump, but the super-clear image from a few pages back labels that as the oxygen turbopump:


And that's clearly a view from the same side (the rotated version shows that the turbopump on the opposite side had the output tubing pointing up, now down):


All this may be academic given the apparent new engine design, but it's still an odd mistake, if it's a mistake.

The people doing the website aren't the same people doing engine design. Mislabelng something is easy if you don't really know what you're looking at. You can email the webmaster and they'll put it on their list of things to fix.

Tim Dodd has a recent video where he goes to an ESA museum and they find a hypergolic rocket engine labeled as a hydrogen engine. Even the pros can mess things up.
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Offline sevenperforce

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Re: Blue Origin's BE-7 engine
« Reply #112 on: 05/31/2023 03:33 pm »
Worth noting that if they are really going with a throat gimbal, it significantly reduces the clearance footprint of each engine, which helps under a small lander.

Shown with a notional 10° gimbal.

Offline meekGee

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Re: Blue Origin's BE-7 engine
« Reply #113 on: 06/01/2023 11:35 am »
Worth noting that if they are really going with a throat gimbal, it significantly reduces the clearance footprint of each engine, which helps under a small lander.

Shown with a notional 10° gimbal.
Curious - are there gimbals in existence that use a virtual pivot point?  Or is it always a physical pivot point?
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Offline spacenut

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Re: Blue Origin's BE-7 engine
« Reply #114 on: 06/01/2023 11:51 am »
The BE-7 seems to be a direct competitor to the RL-10.  How does it compare in pricing?  Thrust range?  As well as other areas to the RL-10?

Glanced through and it seems to be slightly less thrust than RL-10.   I would still like to see some side by side comparisons of BE-7 to RL-10.  Would two BE-7's be able to replace one RL-10?  I'm thinking much lower cost, and thus two to one replacement for upper stage engines like on the Centaur upper stage. 

Also, maybe in another thread, but what happened to BE-3U? 
« Last Edit: 06/01/2023 12:03 pm by spacenut »

Re: Blue Origin's BE-7 engine
« Reply #115 on: 06/01/2023 02:15 pm »
The BE-7 seems to be a direct competitor to the RL-10.  How does it compare in pricing?  Thrust range?  As well as other areas to the RL-10?

Glanced through and it seems to be slightly less thrust than RL-10.   I would still like to see some side by side comparisons of BE-7 to RL-10.  Would two BE-7's be able to replace one RL-10?  I'm thinking much lower cost, and thus two to one replacement for upper stage engines like on the Centaur upper stage. 

BE-7 is not just slightly less thrust than RL-10. Modern RL-10's tend to do around 100-110 kN, while the BE-7 is 44.5 kN according to BO's website. So that's less than half. Now, I personally don't think it's crazy to think that the BE-7 might be a third of the cost of an RL-10, and obviously the math would still check out cost-wise if I'm right, but its certainly a bigger hill to climb.

It's important to consider though, whenever we're talking about Blue Origin, that cost may not the driving issue. They're being bankrolled by one of the richest men in the world, and he doesn't seem to care too much about whether or not they're profitable. I think that it's much more likely that they're building BE-7 just because they need it for their own plans, without any particular interest in competing with RL-10.
« Last Edit: 06/01/2023 02:23 pm by JEF_300 »
Wait, ∆V? This site will accept the ∆ symbol? How many times have I written out the word "delta" for no reason?

Offline sevenperforce

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Re: Blue Origin's BE-7 engine
« Reply #116 on: 06/01/2023 04:02 pm »
Worth noting that if they are really going with a throat gimbal, it significantly reduces the clearance footprint of each engine, which helps under a small lander.

Shown with a notional 10° gimbal.
Curious - are there gimbals in existence that use a virtual pivot point?  Or is it always a physical pivot point?
Not sure what you mean by this. Do you mean a system with two physical separate gimbal mounts with coplanar axes of rotation, as opposed to one gimbal in series below another?

Glanced through and it seems to be slightly less thrust than RL-10.   I would still like to see some side by side comparisons of BE-7 to RL-10.  Would two BE-7's be able to replace one RL-10?  I'm thinking much lower cost, and thus two to one replacement for upper stage engines like on the Centaur upper stage.
As noted, you would need two or three BE-7s to equal an RL-10. One of the advantages of the BE-7 could be significantly higher thrust-to-area. The BE-7 engine has an exit area of 0.694 m2, so its thrust/area ratio is 64.12 kN/m2, higher than every currently-flying or in-development RL10 variant. The RL10's low thrust/area is due to its large nozzle extension which squeezes out extra efficiency, but if the BE-7 can achieve specific impulse over 445 seconds in that much smaller package, then it has a big advantage.

Another advantage is that the BE-7 has a fully regeneratively cooled nozzle. While this prevents the extensible nozzle extension which saves interstage space on the RL10, it means nozzles can be clustered together without heating concerns (one of the issues for EUS). It will probably have slightly lower thrust-to-weight than the RL10, though.

Also, maybe in another thread, but what happened to BE-3U? 
There is another thread. I don't think there have been any significant developments -- at least, not public ones -- since last fall. The BE-3U has had successful test firings without its nozzle extension.

Unless I miss my guess, the BE-3U will hold the record for the physically largest upper-stage engine ever. It's bigger than a J-2 and bigger than an RVac, although its thrust cannot compete with either. Its narrow throttle range also means that it's ill-suited to replace an RL10 in really any application except perhaps something like EUS.

I really wish we had a better engine cycle diagram for either the BE-7 or the BE-3U. The BE-7 is a dual expander, but is it a split expander or not? What's the performance level like? Does this architecture boast specific impulse improvements or thrust-to-weight improvements or reusability improvements or reliability improvements? We don't know. And the BE-3U is supposed to be an open expander, but the website says it has a "back to back turbine assembly" so does that mean a single shaft turbine or is it a dual expander (maybe a full-flow closed expander on the LOX side and a split open expander on the LH2 side?)? What kind of specific impulse can we expect? How's the T/W ratio?
« Last Edit: 06/01/2023 04:04 pm by sevenperforce »

Offline meekGee

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Re: Blue Origin's BE-7 engine
« Reply #117 on: 06/01/2023 06:24 pm »
Worth noting that if they are really going with a throat gimbal, it significantly reduces the clearance footprint of each engine, which helps under a small lander.

Shown with a notional 10° gimbal.
Curious - are there gimbals in existence that use a virtual pivot point?  Or is it always a physical pivot point?
Not sure what you mean by this. Do you mean a system with two physical separate gimbal mounts with coplanar axes of rotation, as opposed to one gimbal in series below another?

Glanced through and it seems to be slightly less thrust than RL-10.   I would still like to see some side by side comparisons of BE-7 to RL-10.  Would two BE-7's be able to replace one RL-10?  I'm thinking much lower cost, and thus two to one replacement for upper stage engines like on the Centaur upper stage.
As noted, you would need two or three BE-7s to equal an RL-10. One of the advantages of the BE-7 could be significantly higher thrust-to-area. The BE-7 engine has an exit area of 0.694 m2, so its thrust/area ratio is 64.12 kN/m2, higher than every currently-flying or in-development RL10 variant. The RL10's low thrust/area is due to its large nozzle extension which squeezes out extra efficiency, but if the BE-7 can achieve specific impulse over 445 seconds in that much smaller package, then it has a big advantage.

Another advantage is that the BE-7 has a fully regeneratively cooled nozzle. While this prevents the extensible nozzle extension which saves interstage space on the RL10, it means nozzles can be clustered together without heating concerns (one of the issues for EUS). It will probably have slightly lower thrust-to-weight than the RL10, though.

Also, maybe in another thread, but what happened to BE-3U? 
There is another thread. I don't think there have been any significant developments -- at least, not public ones -- since last fall. The BE-3U has had successful test firings without its nozzle extension.

Unless I miss my guess, the BE-3U will hold the record for the physically largest upper-stage engine ever. It's bigger than a J-2 and bigger than an RVac, although its thrust cannot compete with either. Its narrow throttle range also means that it's ill-suited to replace an RL10 in really any application except perhaps something like EUS.

I really wish we had a better engine cycle diagram for either the BE-7 or the BE-3U. The BE-7 is a dual expander, but is it a split expander or not? What's the performance level like? Does this architecture boast specific impulse improvements or thrust-to-weight improvements or reusability improvements or reliability improvements? We don't know. And the BE-3U is supposed to be an open expander, but the website says it has a "back to back turbine assembly" so does that mean a single shaft turbine or is it a dual expander (maybe a full-flow closed expander on the LOX side and a split open expander on the LH2 side?)? What kind of specific impulse can we expect? How's the T/W ratio?
The diagram above showed the advantage of a throat (nozzle-only) gimbal.

- Reduced nozzle swing
- Fixed connection to the tanks.

The disadvantage of course is that the throat now has to have the ability to flex.

You can create a linkage between the engine and the thrust structure that forces an engine to pivot around any arbitrary point including for example the throat, without having any physical pivot there.

You get the first advantage, but not the second...  But you also don't have to build a flexible throat.  So it's a trade - a flexible LOx supply path, but a rigid throat.

I don't know of such an implementation, so I was wondering.  It's probably for a reason....
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Online Robert_the_Doll

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Re: Blue Origin's BE-7 engine
« Reply #118 on: 06/01/2023 07:50 pm »
Quote from: meekgee
I don't know of such an implementation, so I was wondering.  It's probably for a reason....

There is a very classic implementation on the Saturn V for the F-1 engines:




Offline meekGee

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Re: Blue Origin's BE-7 engine
« Reply #119 on: 06/02/2023 01:52 am »


Quote from: meekgee
I don't know of such an implementation, so I was wondering.  It's probably for a reason....

There is a very classic implementation on the Saturn V for the F-1 engines:

No,. Not a throat gimbal. Read again.
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Offline AS-503

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Re: Blue Origin's BE-7 engine
« Reply #120 on: 06/02/2023 02:43 am »
Agree with meekGee.
The F1 had a traditional gimbal on the top of the thrust chamber.
Another clue is that the photos clearly show the struts that are actuated by the hydraulic ram are connected to the thrust chamber NOT the nozzle.
It it was a nozzle gimbaled design the struts would be on the nozzle.

Offline sevenperforce

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Re: Blue Origin's BE-7 engine
« Reply #121 on: 06/02/2023 03:51 am »
I feel like the load paths for a virtual gimbal about the nozzle throat would be hella challenging. You're talking about truly immense forces and the natural geometry of the engine already directs those forces up the nozzle and into the combustion chamber axially. Trying to transfer a load into gimbals mounted anywhere other than the chamber...yikes.

Offline edzieba

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Re: Blue Origin's BE-7 engine
« Reply #122 on: 06/02/2023 09:49 am »
The disadvantage of course is that the throat now has to have the ability to flex.
The diagram is misleading: there is no flex at the throat, the engine gimbals about an axis within the throat, but that just means the powerhead swings about the pivot in the opposite direction to the nozzle. The main impact of this is clearance within the engine bay, and that instead of one propellant feed line translating and rotating and one just rotating (assuming it is routed through a topend gimbal) both feed lines translate and rotate. This is not uncommon for vernier engines (e.g. Atlas, Thor, Soyuz).

Tags: be-7 Blue Origin 
 

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