Author Topic: The Reaction Engines Skylon Master Thread (5)  (Read 419901 times)

Offline francesco nicoli

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1680 on: 07/22/2016 07:54 AM »
So, on Friday Richard Varvill will deliver a Skylon Update to the BIS conference. What are they likely to say, and what would you want them to say?

Want them to say?

"we secured (X) customers who have put refundable deposits on our books so we can finally move towards airframe maker selection & speed up ground testing. We will deliver on schedule."

jokes aside, I would like them to develop over recent remarks that the ground test article is going to be "much cheaper originally expected". Is it due to cutting on costs, or is it due to early conservative estimates?
if the latter, is there any hope that (1) the already-confirmed cost reductions for the ground test articles are applicable to the real engines, and that (2) the overall cost estimates are equally conservative?
Could it also be because BAE will be providing a lot of the components without profit margins and sale tax. VAT is 20% cost reduction alone.
on intermediate products, VAT is usually refundable so it shouldn't impact costs... not sure how it works in UK however.

Offline Alpha_Centauri

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1681 on: 07/22/2016 03:45 PM »
Don't suppose anyone was at the BIS talk today?

Offline A_M_Swallow

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1682 on: 07/23/2016 02:15 AM »
{snip} Could it also be because BAE will be providing a lot of the components without profit margins and sale tax. VAT is 20% cost reduction alone.
on intermediate products, VAT is usually refundable so it shouldn't impact costs... not sure how it works in UK however.

In the UK the seller only pays VAT on the price difference. These are exemptions for exports.

Offline john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1683 on: 07/23/2016 10:32 AM »
In a throw-away comment about the title slide, RV joked that PR had come to Reaction engines - the title wasn't anything an engineer would write "Reaction Engines / To Mach 5 and Beyond / the SABREtm solution.
Which suggests the comments about a "highly scaleable" engine in the press release was not loose writing by a PR hack.
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RV confirmed SABRE is designed to be a SSTO engine, but they're investigating TSTO concepts.
Hypersonic passenger transport is too expensive to be practical at the moment. Not going to go into other unmanned craft in this talk.
Wasn't thinking about other unmanned craft until this...
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They continued to use the same SABRE engine diagram as we've seen before, but RV was quite careful to use "This particular design" when describing it, and refer to it as the C1 engine. (with particular reference to the sub zero cooling, and the conical inlet closing shutters)

They are goig to build their own H2 test facility, and have quite detailed plans. (which didn't appear to have LOX tanks I only saw LH2, LHe and LN)
Which is unfortunate as that suggests they won't be investigating (even briefly) the air breathing/ rocket transition, which I'd suggest is a key point where SABRE does diverge from both turbojets and rockets and likely to be an area of "unknown unknowns."  :(
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The SABRE test engine begins at the compressor, has various heat exchangers but doesn't have thrust chambers. From the humanoid figure for scale it's about 4 feet high, five wide and ten deep,
Once the testing of the SABRE cycle is complete, the front and back will be added and testing of the integrated engine can be done. Once that's complete a test engine can be installed into a winged test vehicle and flown. Development of the test vehicle is expected to be around 1bn (I don't know if that's cumulative or additional to the engine costs)
That sounds like an upgraded Nacelle Test Vehicle but running a full airbreathing SABRE. Typically running it with one engine would give very different aerodynamics but I've just had a thought....

Build the test vehicle in the Skylon shape. Put the complete test engine in 1 nacelle and balence it with a straight rocket.  Obviously flights will be short due to high propellant burn but perhaps long enough to get the needed information.
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While too small for the propulsion systems, the National Propulsion Test Facility would probably come in useful for testing the RCS system.
Will this just be the RCS or are they talking the SOMA OMS engine? that' a fairly powerful little beast in its own right.
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REL are particularly hoping BAE can help with the analysis of the CFD at the back of the nacelle (I don't know if that's a reference to the plume issue, or the internal flow)
Could be either. NASA and DLR have mentioned plum [EDIT plume ]impingement on the rear fuselage as a possible concern and detailed airflow around all the rear plumbing is likely to be complex. It'd be terrible to discover the engine has too much drag when some slight layout changes in design could have fixed it.  :(
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Unrelated, Alan Bond is one of the most charismatic people I've met. I wouldn't trust myself to objectively judge anything he said.
Not too obvious on recordings but I suspect he's quite different without a camera in his face. :)

A more common observation is "Does not suffer fools gladly." This is likely to have made interfacing to some government departments quite tense on occasions.
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the C1 engine was designed to run at 100-200 bar, as is required for the high SI.
The air breathing engines in SABRE 4 are more likely to be around 20.
That should make the air breathing pump problems quite a bit easier but that still leaves what they will run the rocket chambers at.  AIUI it's the combination of high pressure rise and low volume that makes the LH2 pump design problem such a PITA.
« Last Edit: 07/24/2016 08:20 PM by john smith 19 »
"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 #1684 on: 07/23/2016 10:37 AM »

Unrelated, Alan Bond is one of the most charismatic people I've met. I wouldn't trust myself to objectively judge anything he said.


I have heard him oncein person  and I wasn't sure about other people but he had that effect on me. He radiates competence and intelligent interest and so on.  I want very much to believe everything he says :-)

Anyhow it's an important skill and I'm sure SABRE/Skylon wouldn't have had the chances it has had without that.

Thanks very very much for your summary - there are some interesting things to digest.

Offline flymetothemoon

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1685 on: 07/23/2016 10:46 PM »
Wasn't thinking about other unmanned craft until this...

Not even this one?



[...] plum impingement [...]

Ooh... Ouchie!  ;D ;)

Offline adrianwyard

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1686 on: 07/24/2016 12:18 AM »
A UAV with hypersonic plum impingement capability would be a war-winning weapon. I expect the USAF to write a cheque for full funding just as soon as they learn what plum is British slang for. :-)

Offline Bob Shaw

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1687 on: 07/24/2016 12:28 AM »
Brexit may kill Skylon, as it would be a logical Ariane 7 and although ESA isn't an aspect of the EU most of the ESA money comes from the EU, and supports EU aerospace...

Online gosnold

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1688 on: 07/24/2016 08:54 AM »
Brexit may kill Skylon, as it would be a logical Ariane 7 and although ESA isn't an aspect of the EU most of the ESA money comes from the EU, and supports EU aerospace...
The ESA money is for Sentinel and Galileo, not for the launcher program.

Offline Alpha_Centauri

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1689 on: 07/24/2016 10:27 AM »
Brexit may kill Skylon, as it would be a logical Ariane 7 and although ESA isn't an aspect of the EU most of the ESA money comes from the EU, and supports EU aerospace...

No, only roughly about ~20% is from the EU, and as per above the vast majority of that is for the Gallileo and Sentinel constellations. Launchers are not funded via the EU.

Besides Skylon was never actually going to be Ariane 7 as the French are the largest investor in launchers, and for obvious political reasons they were never going to sign up to a British idea where their space industry is reliant on a piece of British technology.
« Last Edit: 07/24/2016 11:14 AM by Alpha_Centauri »

Offline john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1690 on: 07/24/2016 08:25 PM »
Brexit may kill Skylon, as it would be a logical Ariane 7 and although ESA isn't an aspect of the EU most of the ESA money comes from the EU, and supports EU aerospace...

No, only roughly about ~20% is from the EU, and as per above the vast majority of that is for the Gallileo and Sentinel constellations. Launchers are not funded via the EU.

Besides Skylon was never actually going to be Ariane 7 as the French are the largest investor in launchers, and for obvious political reasons they were never going to sign up to a British idea where their space industry is reliant on a piece of British technology.
Actually Skylon is dependent on the French made Pyrosic material as much as Skylon would be dependent on SABRE. Each is a critical part of the concept.
"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 knowles2

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1691 on: 07/25/2016 12:49 AM »
Brexit may kill Skylon, as it would be a logical Ariane 7 and although ESA isn't an aspect of the EU most of the ESA money comes from the EU, and supports EU aerospace...

No, only roughly about ~20% is from the EU, and as per above the vast majority of that is for the Gallileo and Sentinel constellations. Launchers are not funded via the EU.

Besides Skylon was never actually going to be Ariane 7 as the French are the largest investor in launchers, and for obvious political reasons they were never going to sign up to a British idea where their space industry is reliant on a piece of British technology.
Actually Skylon is dependent on the French made Pyrosic material as much as Skylon would be dependent on SABRE. Each is a critical part of the concept.

There UK Atomic Energy Authority SYTEM 2 material that REL and some universities was trying to reinvent. I suspect which ever material is chosen, given the size of the vehicle, a substantial investment in manufacturing will be required and therefore the decision will either be purely political, give the French the work to keep them happy or commercial which ever material is the best or which ever manufacture willing to invest in the project with capital and knowledge.

Offline john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1692 on: 07/25/2016 07:11 PM »
Brexit may kill Skylon, as it would be a logical Ariane 7 and although ESA isn't an aspect of the EU most of the ESA money comes from the EU, and supports EU aerospace...

No, only roughly about ~20% is from the EU, and as per above the vast majority of that is for the Gallileo and Sentinel constellations. Launchers are not funded via the EU.

Besides Skylon was never actually going to be Ariane 7 as the French are the largest investor in launchers, and for obvious political reasons they were never going to sign up to a British idea where their space industry is reliant on a piece of British technology.
Actually Skylon is dependent on the French made Pyrosic material as much as Skylon would be dependent on SABRE. Each is a critical part of the concept.

There UK Atomic Energy Authority SYTEM 2 material that REL and some universities was trying to reinvent. I suspect which ever material is chosen, given the size of the vehicle, a substantial investment in manufacturing will be required and therefore the decision will either be purely political, give the French the work to keep them happy or commercial which ever material is the best or which ever manufacture willing to invest in the project with capital and knowledge.
This has no French government involvement. It'a French company making a product. Outside the material Skylon's design is quite conventional, including the size of panels that need to be made. IIRC the ring spacing for the full size Skylon is 0.3m. The panels only grow if they get longer. I think mfg of this size is well within the scale of the French operation.  Wheather they can make enough of them fast enough without substantial scaling up is another matter.  Retaining that standard size would result in a smaller vehicle with fewer panels.
"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 guckyfan

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1693 on: 07/26/2016 08:56 AM »
Outside the material Skylon's design is quite conventional,

That's like the Wright brothers lookin at a 747 and saying "Outside the material and engines this design is quite conventional"

Offline Dalhousie

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1694 on: 07/26/2016 09:42 AM »
Brexit may kill Skylon, as it would be a logical Ariane 7 and although ESA isn't an aspect of the EU most of the ESA money comes from the EU, and supports EU aerospace...

ESA money supports ESA Aerospace.
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Offline RanulfC

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1695 on: 07/28/2016 05:53 PM »
Outside the material Skylon's design is quite conventional,

That's like the Wright brothers lookin at a 747 and saying "Outside the material and engines this design is quite conventional"

Just to be clear, that actually IS what they would say if they saw a 747 and it was explained and demonstrated for them. They weren't stupid, (rather stubborn, more than a little vain, and certainly grasping and vindictive, but NOT stupid) and would have easily realized how its operation compared to their own work. It was the direction their own work was going and obvious by the work of others around them. There are details that they would have trouble understanding at first because of their knowledge base, but in general they'd see the 747 layout as very 'conventional',  requiring advanced materials and propulsion far in advance of what they had available certainly but recognizable from their own knowledge.

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Offline CameronD

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1696 on: 07/29/2016 12:01 AM »
...... There are details that they would have trouble understanding at first because of their knowledge base, but in general they'd see the 747 layout as very 'conventional',  requiring advanced materials and propulsion far in advance of what they had available certainly but recognizable from their own knowledge.

Mebbe add 'controls' to that list.  The Wright brothers didn't invent the joystick/rudder pedals (that came later over in Europe) so they wouldn't recognise anything in the cockpit either.  :)
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Online high road

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1697 on: 07/29/2016 11:24 AM »
...... There are details that they would have trouble understanding at first because of their knowledge base, but in general they'd see the 747 layout as very 'conventional',  requiring advanced materials and propulsion far in advance of what they had available certainly but recognizable from their own knowledge.

Mebbe add 'controls' to that list.  The Wright brothers didn't invent the joystick/rudder pedals (that came later over in Europe) so they wouldn't recognise anything in the cockpit either.  :)

The fly-by-wire and autopilot function (even when not on the actual autopilot) that are part of current controls are even more important developments that allow airplane sizes and flight lengths that would be prohibitively taxing for pilots with direct mechanical control. That is something that would be hard to explain to them from their 19th - early 20th century reference. (well, they'd probably think it's an actual AI flying the plane).

New material, new engines, smaller wings than ever before (while still functioning as an airplane), dedicated landing strips, 'detachable' carbo bay that can be preloaded and quickly swapped upon landing... About as run-off-the-mill as, say, Thunderbird II. (That one can even land propulsively. Best of both worlds :p)

Offline john smith 19

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1698 on: 07/29/2016 11:18 PM »
...... There are details that they would have trouble understanding at first because of their knowledge base, but in general they'd see the 747 layout as very 'conventional',  requiring advanced materials and propulsion far in advance of what they had available certainly but recognizable from their own knowledge.

Mebbe add 'controls' to that list.  The Wright brothers didn't invent the joystick/rudder pedals (that came later over in Europe) so they wouldn't recognise anything in the cockpit either.  :)
The Wright brothers in 1903 probably. By 1913 (by which time Bleriot had flown the English Channel) they would recognize a control wheel with rudder and flaps.

The fly-by-wire and autopilot function (even when not on the actual autopilot) that are part of current controls are even more important developments that allow airplane sizes and flight lengths that would be prohibitively taxing for pilots with direct mechanical control. That is something that would be hard to explain to them from their 19th - early 20th century reference.
In 1903 maybe, by 1914 Sperry had already demonstrated an autopilot

https://en.wikipedia.org/wiki/Lawrence_Sperry.

IIRC By 1920 the word "Drone" had already been seen in science fiction stories by EE Smith and small radio controlled aircraft were in use as gunnery targets by the early 1920's.
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(well, they'd probably think it's an actual AI flying the plane).
Wrong. Explaining electronics that complex would be difficult, but the concept would be there.  This technology has been around for a lot longer than you seem to realize.
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New material, new engines, smaller wings than ever before (while still functioning as an airplane),
Wing loading for the MD MD11F was 844 Kg/m^2. That was for a passenger carrying airliner. I don't have  a figure for wing area for Skylon but anything above 386 m^2 would put it's wing loading below that.
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dedicated landing strips,
Wrong again. A dedicated launch runway to orbit, but in air breathing only mode Skylon can take off from a much wider range of runways. Most of the length is to meet emergency stop criteria for the fully loaded vehicle, which only apply when it's fully loaded to go to orbit. Landing is much easier with a low empty weight and no engine noise issues.
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'detachable' carbo bay that can be preloaded and quickly swapped upon landing...
Much like how most passenger luggage is shipped in fact.
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About as run-off-the-mill as, say, Thunderbird II. (That one can even land propulsively. Best of both worlds :p)
You really need to either read up on what Skylon or stop putting up so many strawman arguments.   :(

For those who don't really know that much about Skylon I'll say it's designed like the SR71 to be as radical as it needs to be (in terms of materials and systems) to get the job done. 

REL are very conscious of the perception (and actual) level of risk of the project. Outside of the critical areas needed to make it work they have aimed to go with the most boring mature technology possible. This explains why they went with riveting for examples, despite the huge advances in adhesives. They are confident they can make (and test) rivets in the size and shape needed to do the job, whereas an adhesive that can provably operate over the full Earth to space pressure / temperature range is likely a major research project on its own.  Likewise AFAIK the tanks are spec at a regular Al alloy, not AlLi. Mfg of such tanks is fairly widespread, while AlLi is a niche material and it's not needed to get the job done.

But the top level story. It's a twin engine low wing monoplane with a payload bay in the mid body made by riveting skin panels to a framework which takes off and lands horizontally, like a few thousand other designs in the last 100 years but unlike the only 3 partially reusable space vehicles that have flown.
"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 Paul451

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Re: The Reaction Engines Skylon Master Thread (5)
« Reply #1699 on: 07/30/2016 01:13 AM »
[Wright Bros and 747s.]

The point of that analogy was that the 747 flies by principles understood in the first decade of aviation, in spite of still being completely and utterly impossible to build at the time.

'detachable' carbo bay that can be preloaded and quickly swapped upon landing...
Much like how most passenger luggage is shipped in fact.

No aircraft uses a detachable cargo section that must function as an integrated part of the vehicle. ULD's are not even remotely analogous.

It's that kind of exaggeration that makes people so sceptical of the continual claims that Skylon has no "showstoppers".

[The only aircraft I've seen with detachable cargo-pod was the failed Fairchild XC-120 "Packplane".]

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