The Reaction Engines Skylon/SABRE Master Thread (6)

[john smith 19]

It would then be up to the mfg company ("Skylon PLC" to give it a name) to execute the order.

On a tangent, Skylon Enterprise Ltd was dissolved just over a year ago

Interesting. I dimly recall someoen saying they were the part of the group that was talking to the CAA regarding the legal aspects of operating in UK airspace.

So either their work is done and its no longer needed or that's not going to happen in the near future. Time will tell what the answer to that question will be.

[JCRM]

So either their work is done and its no longer needed or that's not going to happen in the near future. Time will tell what the answer to that question will be.

It could be the separation of SABRE from Skylon was in place in case funding went a different way than the eventual investment from BAe; it could be BAe want the airframe research; it could be part of the preparations for Bond's retirement. We may never know.

[JCRM]

The "SABRE Technology Development – Pathways to Flight" paper being presented at the Space Propulsion Conference in Seville next week might make interesting reading.

REL's planned TPS [supplier], who are (AFAIK) French.

I haven't seen mention of Pyromel Systems for a while, and the newsof them having recreated the manufacturing process for System 2 was with Imperial College

[john smith 19]

The "SABRE Technology Development – Pathways to Flight" paper being presented at the Space Propulsion Conference in Seville next week might make interesting reading.

Definitely.

REL's planned TPS [supplier], who are (AFAIK) French.

I haven't seen mention of Pyromel Systems for a while, and the newsof them having recreated the manufacturing process for System 2 was with Imperial College

True. OTOH I've not seen any mention of alternative bulk supplier in the UK.

[FutureSpaceTourist]

Progress in the last year for the development of @reactionengines revolutionary space rockets testbed #TF1 #SABRE - designed to unlock the future of space travel and hypersonic flight @WestcottVP @colintheobald

https://twitter.com/westcottvp/status/994531125883174912

[adrianwyard]

A new artists' depiction of a Skylon launch and docking with the ISS:



They have rather cleverly shown a BFS already docked to the space station, presumably in the hopes it will lessen the 'it's never gonna happen' comments from the SpaceX true-believers. 

[john smith 19]

A new artists' depiction of a Skylon launch and docking with the ISS:



They have rather cleverly shown a BFS already docked to the space station, presumably in the hopes it will lessen the 'it's never gonna happen' comments from the SpaceX true-believers. 

I'll note that SABRE burns air and LH2 or LO2 and LH2. The exhaust on this CGI looks quite smokey.

it is 82m long, so yes it is longer, but I think the proportions relative BFS aren't good. BFS is about 2x the dia of Skylon.

[chipguy]

I'll note that SABRE burns air and LH2 or LO2 and LH2. The exhaust on this CGI looks quite smokey.

Does the SABRE running with air generate sufficient temperature and pressure to
form N/O compounds? A little of that would tinge the exhaust reddish brown.

[john smith 19]

I'll note that SABRE burns air and LH2 or LO2 and LH2. The exhaust on this CGI looks quite smokey.

Does the SABRE running with air generate sufficient temperature and pressure to
form N/O compounds? A little of that would tinge the exhaust reddish brown.

Perhaps, but not actually smokey
OTOH the SABRE 4 cycle uses a much lower chamber pressure for the AB cycle. During REL's work on the LAPCAT programme they found a new combustor design that's believed to radically reduce NoX production. Assuming it's viable at the chamber pressures of SABRE then NoX should not be visible.

[CrewtaiL]

http://aviationweek.com/aviation-week-space-technology/turbojet-runs-precursor-hypersonic-engine-heat-exchanger-tests

No access to full article, unfortunately, but HX tests this month, it seems.

[JCRM]

http://aviationweek.com/aviation-week-space-technology/turbojet-runs-precursor-hypersonic-engine-heat-exchanger-tests

No access to full article, unfortunately, but HX tests this month, it seems.

REL have it reprinted on their site

TL;DR They're testing the test rig, not the heat exchangers - "Full heat exchanger testing expected to begin in third quarter"

It's quite exciting though, once calibrated, rather than just test at a particular temperature, the rig will allow them to simulate a whole flight by varying temperature, pressure and flow rate.
Also of note is

The unit [...] is a “newer” version of previously developed HTXs says Reaction Engines CEO Mark  Thomas

[Star One]

This appears to be an update of the original article from AV.

Turbojet Runs Precursor to Hypersonic Engine Heat Exchanger Tests

Advanced propulsion developer Reaction Engines is nearing its first step toward validating its novel air-breathing hybrid rocket design at hypersonic conditions by firing up a vintage General Electric J79 turbojet to act as a heat source for testing, expected later this month. The ex-military engine, formerly used in a McDonnell Douglas F-4, is a central element of Reaction’s specially developed high-temperature airflow test site, which will soon be commissioned at Front Range ...

http://m.aviationweek.com/defense/turbojet-runs-precursor-hypersonic-engine-heat-exchanger-tests

[john smith 19]

REL have it reprinted on their site

TL;DR They're testing the test rig, not the heat exchangers - "Full heat exchanger testing expected to begin in third quarter"

It's quite exciting though, once calibrated, rather than just test at a particular temperature, the rig will allow them to simulate a whole flight by varying temperature, pressure and flow rate.
Also of note is

The unit [...] is a “newer” version of previously developed HTXs says Reaction Engines CEO Mark  Thomas

Definitely.

The question is wheather the you can dynamically vary the conditions while the rig is running? The article says then can ramp up/down the conditions the inlet is exposed to, which is good, but not explicitly that can happen while the turbojet is running (it implies some fairly hefty flow control doors).

If not then trajectory simulation will be a series of point tests gradually varying the inlet flow/temperature profile to build up the results.

OTOH a dynamic system could run a complete trajectory like it the HX was sitting in front of a SABRE test engine on a FTV.

The latter would be more expensive initially but add significant value to such a facility and (being a more realistic demonstration of a Skylon flight) lower technology risk further.

I'm really hoping REL have gone the extra mile on this.  I think it will be the first new high temperature hypersonic capable test facility in the US in decades.

[JCRM]

The question is wheather the you can dynamically vary the conditions while the rig is running? The article says then can ramp up/down the conditions the inlet is exposed to, which is good, but not explicitly that can happen while the turbojet is running (it implies some fairly hefty flow control doors).

I took "The whole set up allows us to do flight-like tests,” to indicate it could be varied dynamically.

I think it will be the first new high temperature hypersonic capable test facility in the US in decades.

where does it indicate it will be hypersonic capable?

[john smith 19]

I took "The whole set up allows us to do flight-like tests,” to indicate it could be varied dynamically.

I certainly hope you're right, and I think it would be a very sensible way to go, but I don't think they've actually said it, have they?

where does it indicate it will be hypersonic capable?

Well the temperature and flow range but (in hindsight) I can see how they' have those but not the actually velocity needed to make it a true hypersonic facility.

Obviously time will tell wheather this is a real limitation or makes no effective difference.

[JCRM]

I took "The whole set up allows us to do flight-like tests,” to indicate it could be varied dynamically.

I certainly hope you're right, and I think it would be a very sensible way to go, but I don't think they've actually said it, have they?

I think they said it:

"By mixing the flow we can control the ramp up and down, and it allows us to dial in the appropriate conditions so the pre-cooler will see an environment analogous to what it would see in a flight vehicle over a flight time line. If your vehicle took off from a runway and accelerated to Mach 5 over the next 4-5 min. we can dial in the temperatures, pressures and mass flows corresponding to that ascent"

If "time line" and "4-5 min" were not included, then it could refer to point testing.

where does it indicate it will be hypersonic capable?

Well the temperature and flow range but (in hindsight) I can see how they' have those but not the actually velocity needed to make it a true hypersonic facility.

REL have always said because the shock intake isolates the engine it only needs a subsonic test facility. If it were possible to make a continuous operation supersonic wind tunnel out of an old jet engine and some steel piping then there would be a lot more of them about, and REL wouldn't need to build this facility.

Obviously time will tell wheather this is a real limitation or makes no effective difference.

Provided the airflow in the simulated inlet matches that behind a real intake it'll be fine. If the work Bayern-Chemie has done ("These intakes will be fully characterized across the flight Mach number range") has given them good data, it'll be fine. If it isn't possible to break the design problem down like that then SABRE probably isn't viable

[john smith 19]

I'm not sure if anyone else has mentioned this presentation.

https://futurepowertrains.co.uk/wp-content/uploads/2017/12/Tom-Burvill.pdf

I'll note the overall style of the slides has changed a bit but I think the interesting stuff are at slides 8 and 17, with revised SABRE cutaways and development timeline.

In particular their "Integrated Test" time frame is 2022-24 while their "Flight Test" is targeting  2023-25

[edzieba]

Looks like an older version of the slides used at the Mark Wood lecture (some numbers changed, missing later slides on additional applications).

[john smith 19]

Looks like an older version of the slides used at the Mark Wood lecture (some numbers changed, missing later slides on additional applications).

Noted.  The time line was interesting, and they still seem interested in doing a flight vehicle, which I'm pretty curious about, given how tough a single engine LH2 fueled vehicle is.

[JCRM]

they still seem interested in doing a flight vehicle, which I'm pretty curious about, given how tough a single engine LH2 fueled vehicle is.

What's (particularly) tough about a single hydrogen engine test vehicle? Center of mass can be handled by ballast (or ballast tanks if dynamic control is needed)