Author Topic: The Reaction Engines Skylon Master Thread (5)  (Read 419697 times)

Online john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #480 on: 07/30/2015 04:26 PM »
guys, did you see the design for an airbreathing nuclear rocket reported by nextbigfuture? I know that it's just summer speculation, but I was wondering whether an integrated design with the SABRE is, as a pure matter of principle, possible.

http://nextbigfuture.com/2015/07/nuclear-thermal-turbo-rocket-with.html
You need to develop a bit more of a feel for engineering.  :(

This thing starts with an unflown concept and stacks the untested ideas on top of it.  Variable pitch fan blade trailing edges structured as linear aerospikes ducting 2000c GH2 through them ::) Most metals melt below this temperature. 

At the end of it you've got something with maybe an Isp of 900sec + and double thrust for a period.

SABRE delivers somewhere around 2-4000 secs without a nuclear fuel element in site.

The Aviationweek article is now generally available.  I suppose the idea is that subscribers get it early but the public gets it eventually.

Here's the link again:
http://aviationweek.com/technology/air-breathing-sabre-concept-gains-credibility?NL=AW-05&Issue=AW-05_20150730_AW-05_233&sfvc4enews=42&cl=article_1&utm_rid=CPEN1000001204273&utm_campaign=3312&utm_medium=email&elq2=de275daceef84b74b5541bcb84290e12

Tried to log in but failed to do so.

Then I read the level of the comments left.

Deeply disappointing.   :(

That is a statement based on bias and not supported by any relevant data.  Not all gov't contracts are cost plus.
I think the LM annual accounts is very relevant data if you're trying to decide how much of a companies revenue comes from being a government contractor or from selling in the open market.

And I have so far said nothing about what proportion of LM's contracts are cost plus or firm fixed price.

I fully accept that something like the Orion capsule will be cost plus (I don't know about you but I'm so excited for when that SM comes in from Europe and it's mated to the capsule for the first time. I'm sure it'll be worth the wait)

OTOH I doubt the F35 production contract is cost plus, give that should have all been worked out in development (although judging by that shoot out with an F16 described in this edition the flight control system seems a bit of tweaking).

Fairly simple the military will always get first dibs on something like this once they are persuaded it works and does what it says on the can.
Unfortunately it doesn't work that way. They may like the technology but the USAF cannot develop it. It has to have a "competition" or very good reasons to have a single source to get a programme going and of course that would leave the USAF with an engine but no aircraft.

Since REL don't make aircraft, that's the job of the Skylon mfg consortium, that leaves them in something of an impasse.
Quote
The commercial sector is often more risk adverse and though the military can be conservative in these things as well, if they are persuaded they are far more likely to put money into something like this.
That's a very sweeping generalization. Strictly speaking it will be the US Congress who puts US taxpayers money into it.

At present I think the USAFRL study provides a strong case to US readers that the technology works.
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline t43562

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #481 on: 07/30/2015 04:58 PM »
I have an unpaid login - perhaps that's why I could read it.  It wasn't available to me until today though - perhaps there is some progression.

The interesting bits to me were sort of casting doubt on Skylon being the first application of Sabre.

I'm not sure about copyright so I'm quoting the quotes as I doubt they can be owned:

Quote
"The question to answer next is what benefit the Sabre could bring to high-speed aerospace vehicles compared to other propulsion systems,”

“AFRL is analyzing vehicle designs based on the Sabre engine concept. We are also considering testing their heat-exchanger technology at Mach 5 flight conditions in a high-temperature wind tunnel.”
(Hellman, AFRL)

Skylon is:
Quote
“very risky as a first application,”
“Sabre may provide some unique advantages in more manageable two-stage-to-orbit configurations.”
(Hellman, AFRL)

Quote
“From our perspective there is no cheap, quick way around the problem of space access. We’ve done studies and we agree that [a] sensible second-stage approach might be best to demonstrate the technology by taking it one step at a time,”
(Sam Hutchison, Reaction Engines)

Quote
“Enough people now say the Sabre cycle works and it looks compelling. Now the question is what will we do with it?“ As an engine class, it straddles both air and space, so we have to optimize a system to take advantage of that for a given application. As we structure the development plan going forward, we can figure out what the first use is going to be. So over the next six months we will be closing in on that application.”

“Right now we are in the process of scoping that demonstration engine in terms of what it needs to achieve,”

“The key thing is to tick the boxes in every area it needs to tick. It is all about making sure the demonstrator meets the performance requirements that are set for it. We want to make sure it really works and offers the sort of performance that we say it can do. We’re still in that phase. The studies are in their infancy for the engine demonstrator but we have got to make sure we’re not biting off too much more than we can chew.”

(Hutchison)

Apparently the demonstrator is on track to do a full engine test in  2018/2019.

Ground testing is possible :
Quote
“because the engine uses the atmosphere as the source of its energy and the reaction mass. And because of the clever heat-exchanger technology, we can modulate the air so the turbomachinery in the engine doesn’t know it is on the ground.”
(Hutchison) 

They plan to simulate higher velocity air by raising the temperature of the air entering the inlet. They are also going to do wind tunnel tests with the inlet.

The AFRL suggest that they might do Mach 5 tests in a high temperature wind tunnel.

There are apparently no short term funding shortfalls.
« Last Edit: 07/30/2015 05:00 PM by t43562 »

Offline Moe Grills

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #482 on: 07/30/2015 05:04 PM »
That's a very sweeping generalization. Strictly speaking it will be the US Congress who puts US taxpayers money into it.

At present I think the USAFRL study provides a strong case to US readers that the technology works.
[/quote]

You may not approve, but I would like to make a "sweeping generalization" by saying that the Skylon/Sabre-engine technology may be the proverbial "silver bullet" that space-travel enthusiasts/fans have been waiting for for decades.
At least for travel from ground to LEO and back.
For the proverbial "silver bullet" for space-travel and space projects beyond LEO to deep space?  Skylon is not the answer to that need, but maybe that sensationalized EM Drive I've read about recently (if it works) may fit
hand-in-glove with Skylon to revolutionize space-travel completely. When was the last time "REVOLUTIONIZE" has been used authentically and verifiably to describe new/advanced  tech developments for space-travel? 

Offline Star One

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The Reaction Engines Skylon Master Thread (5)
« Reply #483 on: 07/30/2015 05:43 PM »
LM have the SR-72 concept which is looking for a pair of engines. The thing is these prototype programs can often end up black budget items where it's hard to see what's happening with them.
« Last Edit: 07/30/2015 05:43 PM by Star One »

Online john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #484 on: 07/30/2015 06:57 PM »
LM have the SR-72 concept which is looking for a pair of engines. The thing is these prototype programs can often end up black budget items where it's hard to see what's happening with them.
No they are not.  They have partnered with Aerojet Rocketdyne for a turbo ram/SCRamjet  engine.

LM think they already have an engine for their concept (and it's nowhere near cutting metal at this point).
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline Star One

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #485 on: 07/30/2015 08:32 PM »

LM have the SR-72 concept which is looking for a pair of engines. The thing is these prototype programs can often end up black budget items where it's hard to see what's happening with them.
No they are not.  They have partnered with Aerojet Rocketdyne for a turbo ram/SCRamjet  engine.

LM think they already have an engine for their concept (and it's nowhere near cutting metal at this point).

Concepts can change. As you've just pointed out this whole thing is a paper exercise at this point so there's nothing stopping things being altered at this time.

Offline livingjw

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #486 on: 07/30/2015 10:32 PM »
If we assume that the engine works as advertised, what is it good for. It cannot possibly do SSTO while airbreathing to only Mach 5 without extremely advanced materials. A TSTO reusable design can be more easily accomplished with a TSTO rocket or rocket boosted Scramjet. So what mission would it do better than some other technology? I really don't understand the fascination with this cycle, which dates back to the 1960's.

Offline QuantumG

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #487 on: 07/30/2015 10:41 PM »
Welcome to the forum livingjw.. I see you've taken Jon Goff's advice on learning about things on the Internet.
Jeff Bezos has billions to spend on rockets and can go at whatever pace he likes! Wow! What pace is he going at? Well... have you heard of Zeno's paradox?

Online john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #488 on: 07/30/2015 11:24 PM »
Welcome to the forum livingjw.. I see you've taken Jon Goff's advice on learning about things on the Internet.
Neatly demonstrates why I didn't persist with getting the free logon to AV&ST.  :(
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline Citizen Wolf

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #489 on: 07/31/2015 02:15 AM »
@Livingjw

Ooow, you came in with a howler of a poor question there as a first post.

As a starter, check out reaction engines website: http://www.reactionengines.co.uk/

But as a quick answer to your question, the SABRE engine is a dual air-breathing AND rocket engine. The air-breathing cycle has a rather nifty and advanced heat-exchanger to stop things melting. If it performs to expectations, SABRE should do SSTO.


« Last Edit: 07/31/2015 02:17 AM by Citizen Wolf »
The only thing I can be sure of is that I can't be sure of anything.

Online john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #490 on: 07/31/2015 11:28 AM »
Skylon is:
Quote
“very risky as a first application,”
“Sabre may provide some unique advantages in more manageable two-stage-to-orbit configurations.”
(Hellman, AFRL)
SABRE is designed to do one job. Get the vehicle it's attached to from a standing start on a runway to Low Earth Orbit.

If they didn't want that they should have said so and asked either for a hypersonic cruise engine like LAPCAT (which is very different internally) or the HX technology to put on the front of a turbofan.

It seems they either didn't realize how closely this is tied into the use of LH2 or they didn't really believe it could work at all.  Unfortunately now they've run the analysis themselves they now realize it can, and they're not sure what to do about it.  :(
Quote
(Sam Hutchison, Reaction Engines)

Quote
“Enough people now say the Sabre cycle works and it looks compelling. Now the question is what will we do with it?“ As an engine class, it straddles both air and space, so we have to optimize a system to take advantage of that for a given application. As we structure the development plan going forward, we can figure out what the first use is going to be. So over the next six months we will be closing in on that application.”

“Right now we are in the process of scoping that demonstration engine in terms of what it needs to achieve,”

“The key thing is to tick the boxes in every area it needs to tick. It is all about making sure the demonstrator meets the performance requirements that are set for it. We want to make sure it really works and offers the sort of performance that we say it can do. We’re still in that phase. The studies are in their infancy for the engine demonstrator but we have got to make sure we’re not biting off too much more than we can chew.”

(Hutchison)

Are you sure this guy works for REL? That's just amazingly lukewarm. I'd guessed REL had a pretty good idea of what they needed the demonstrator to demonstrate.
Quote

Apparently the demonstrator is on track to do a full engine test in  2018/2019.

Ground testing is possible :
Quote
“because the engine uses the atmosphere as the source of its energy and the reaction mass. And because of the clever heat-exchanger technology, we can modulate the air so the turbomachinery in the engine doesn’t know it is on the ground.”
(Hutchison) 

They plan to simulate higher velocity air by raising the temperature of the air entering the inlet. They are also going to do wind tunnel tests with the inlet.

The AFRL suggest that they might do Mach 5 tests in a high temperature wind tunnel.

There are apparently no short term funding shortfalls.
The precooler (and it's frost control) were a)The thing that lets the engine see near constant inlet conditions from 0 to M5.5, so allowing you to design an efficient engine for a fairly narrow operating range, instead of a one size fits all, to be adequate over the whole range, and b) The one thing that had never been fully tested.

The point I note is that patents can tell you that if you make a HX of a certain size with tubes of a certain size and frost control working a certain way it will let you do certain things.

But they don't tell you how to do those things.

I sincerely hope those matters stay within REL.
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline Citizen Wolf

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #491 on: 07/31/2015 01:46 PM »
Sam Hutchison
**As we structure the development plan going forward, we can figure out what the first use is going to be.**

That sounds like a really odd thing for someone from REL to say. Was he thinking one thing and said another. I thought they knew what the first use of the SABRE was going to be. I thought they had designed it from the start to be an SSTO. Nothing else. Not a sub-orbital whatever, or a high-Mach quick reaction craft for USAF.  wtf?
The only thing I can be sure of is that I can't be sure of anything.

Offline lkm

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #492 on: 07/31/2015 02:22 PM »
Sam Hutchison
**As we structure the development plan going forward, we can figure out what the first use is going to be.**

That sounds like a really odd thing for someone from REL to say. Was he thinking one thing and said another. I thought they knew what the first use of the SABRE was going to be. I thought they had designed it from the start to be an SSTO. Nothing else. Not a sub-orbital whatever, or a high-Mach quick reaction craft for USAF.  wtf?
It might be helpful to remember that Sam Hutchison is Director of Corporate Development at REL and  CEO of Skylon Enterprises Ltd so from his perspective he's probably saying that they've got this great piece of technology that they're going to build a SSTO with but which can usefully be applied to a bunch of other tasks on a quicker time frame at lower costs with a small amount of effort on their part so they're in the process of working out which use cases are worth pursuing in order to generate income while they work on Skylon.

Offline lkm

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #493 on: 07/31/2015 02:32 PM »
Skylon is:
Quote
“very risky as a first application,”
“Sabre may provide some unique advantages in more manageable two-stage-to-orbit configurations.”
(Hellman, AFRL)
SABRE is designed to do one job. Get the vehicle it's attached to from a standing start on a runway to Low Earth Orbit.

If they didn't want that they should have said so and asked either for a hypersonic cruise engine like LAPCAT (which is very different internally) or the HX technology to put on the front of a turbofan.

It seems they either didn't realize how closely this is tied into the use of LH2 or they didn't really believe it could work at all.  Unfortunately now they've run the analysis themselves they now realize it can, and they're not sure what to do about it.  :(
Could you explain  perhaps exactly how you see SABRE 4 and Scimitar as very different internally? To my eyes SABRE 4 seems Scimitar inspired.

Offline flymetothemoon

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #494 on: 07/31/2015 08:16 PM »
As we structure the development plan going forward, we can figure out what the first use is going to be. So over the next six months we will be closing in on that application.”

“Right now we are in the process of scoping that demonstration engine in terms of what it needs to achieve,”
ly hope those matters stay within REL.

It does sound a bit disappointing. It reads like might be getting guided by partners (the USAF?) as to what prototype they build to suit partner requirements. Maybe that seems the best reliable place they can get the money from for their prototype. Still that might turn out to be a great technology demonstrator flight application that might actually get built and prove the technology much quicker than any of us hoped - which wouldn't in itself be a bad thing.... it would still be a diversion from the creation of Skylon though which delays the Skylon dream further!

Offline adrianwyard

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #495 on: 07/31/2015 08:56 PM »
I'm confident you're reading too much into this. It would be a different matter if Alan Bond said "we're switching to TSTO" publicly, but here you have their Director of Corporate Development sound just exactly like someone in that role should: he's being broadly supportive of the AFRL statement - i.e. their recent partner who they may hope to work with again (read $$$$ that could help further the Skylon project).

Offline Star One

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The Reaction Engines Skylon Master Thread (5)
« Reply #496 on: 07/31/2015 09:01 PM »
I'm confident you're reading too much into this. It would be a different matter if Alan Bond said "we're switching to TSTO" publicly, but here you have their Director of Corporate Development sound just exactly like someone in that role should: he's being broadly supportive of the AFRL statement - i.e. their recent partner who they may hope to work with again (read $$$$ that could help further the Skylon project).

How would we know there not still actively working with the USAF, it may not be something the USAF wish broadcasting.

I personally feel if the USAF want a hypersonic vehicle of some type then REL are their best best to achieve this.
« Last Edit: 07/31/2015 09:04 PM by Star One »

Offline adrianwyard

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #497 on: 07/31/2015 09:18 PM »
I suppose they could be. And that would be one more reason it would be smart to ensure comments made in public are in sync.

(By way of contrast it would not be wise for REL to say "SABRE is for SSTO, if USAF don't get that they're idiots. But we'll take their money anyway.)"

And we may as well remember that the cautious amongst us could be right. An unforeseen performance/mass issue could yet kill hopes of SSTO.

Offline lkm

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #498 on: 07/31/2015 10:55 PM »
I'm confident you're reading too much into this. It would be a different matter if Alan Bond said "we're switching to TSTO" publicly, but here you have their Director of Corporate Development sound just exactly like someone in that role should: he's being broadly supportive of the AFRL statement - i.e. their recent partner who they may hope to work with again (read $$$$ that could help further the Skylon project).

How would we know there not still actively working with the USAF, it may not be something the USAF wish broadcasting.

I personally feel if the USAF want a hypersonic vehicle of some type then REL are their best best to achieve this.

According to their press release regarding the results of the CRADA it is an ongoing relationship as it states :

"Reaction Engines Ltd. and AFRL are now formulating plans for continued collaboration on the SABRE engine; the proposed work will include investigation of vehicle concepts based on a SABRE derived propulsion system, testing of SABRE engine components and exploration of defence applications for Reaction Engines’ heat exchanger technologies."

Note it states "SABRE derived" regarding what they want to put in a vehicle.


Offline t43562

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #499 on: 08/01/2015 06:56 AM »
It seems to me that there could be a chance for REL to develop something which would not be economically worthwhile  if done by themselves but might be militarily worthwhile to the USAF.

How could one turn up one's nose at a chance to try out some aspects of Skylon/Sabre without needing to go directly to a $10 billion SSTO?  It could be a godsend.

That might control what aspects the engine demonstrator has to be most realistic about, how much money has to be spent on it and where.


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