Author Topic: The Reaction Engines Skylon/SABRE Master Thread (6)  (Read 404759 times)

Offline momerathe

  • Full Member
  • *
  • Posts: 150
  • Liked: 73
  • Likes Given: 36
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #480 on: 12/25/2016 09:18 pm »
The only benefit of SABRE over ramjet is start from zero speed to supersonic , which could also be done by conventional rocket engine, no heavier than the SABRE core and cost ~20% of total propellant.

I'm pretty sure the bolded statement is wrong. A conventional rocket has lower effective ISP, and therefore must use more fuel, almost by definition.

You're misinterpreting what Katana is saying.  When Katana says "cost ~20% of total propellant" that means cost in addition to the prop that would be there for SABRE.  That's because Katana is agreeing with you that Isp is higher for SABRE so 20% more prop is needed for the non-SABRE alternative.

Oh okay, fair enough. If that's the case then I did misinterpret, my bad. Still, that 20% could easily be the difference between a design closing or not.

thermodynamics will get you in the end

Offline lkm

  • Full Member
  • ****
  • Posts: 520
  • Liked: 106
  • Likes Given: 1
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #481 on: 12/26/2016 11:10 am »
SABRE runs very close to ramjet at M5.

Heat absorbing capability of LH2 is about 1/10 of combustion energy release. While at M5 the energy of air is near to combustion energy release. So the amount of cooled air is much lesser than hydrogen used in cooling, most part of hydrogen are burned in bypass channel.
I'm not clear what point you're trying to make. Could you be a little clearer?
At high Mach number the SABRE core could only cool and compress tiny amounts of extremely hot air. The operation cycle and hence the thrust performance converges to standard ramjet, and the core becomes dead weight.

The only benefit of SABRE over ramjet is start from zero speed to supersonic , which could also be done by conventional rocket engine, no heavier than the SABRE core and cost ~20% of total propellant.

The structure weight and fuel consumption of standard ramjet+rocket is not much worse than SABRE, but much easier to build.
Ok, so that's just not true. At Mach 5 the engines at its most efficient. The nacelle intake is capturing 380kg/s of which only 17kg/s is going to the ramjet bypass, that's less than 5%. We know this because as John said there's a trajectory spreadsheet that tells us.

Offline Star One

  • Senior Member
  • *****
  • Posts: 13457
  • UK
  • Liked: 3729
  • Likes Given: 220
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #482 on: 01/16/2017 06:34 am »
New video from BAE featuring a Skylon like vehicle carrying out advanced ISR.


Offline momerathe

  • Full Member
  • *
  • Posts: 150
  • Liked: 73
  • Likes Given: 36
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #483 on: 01/16/2017 03:50 pm »
It's not obvious what the advantages of such a platform would be over a satellite, but hey, at least the military vapourware peddlers haven't forgotten us ;).

Also, before watching that video I had no idea atmospheric lensing was a thing. Most references describe it as a problem for laser transmission, rather than a exploitable phenomenon though.
thermodynamics will get you in the end

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 9902
  • Everyplaceelse
  • Liked: 2312
  • Likes Given: 12824
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #484 on: 01/16/2017 04:34 pm »
It's not obvious what the advantages of such a platform would be over a satellite, but hey, at least the military vapourware peddlers haven't forgotten us ;).
Lucky us.  :(
There is a benefit in that satellites are highly predictable in their paths and timing.  Aircraft less so.
Quote
Also, before watching that video I had no idea atmospheric lensing was a thing. Most references describe it as a problem for laser transmission, rather than a exploitable phenomenon though.
AFAIK it's not.

That is still vaporware.

The video suggests it's possible to pulse heat patches of the atmosphere and combine the improved optical properties into superior images. It's not clear if this is a sort of photo-mosaic concept or if they are talking about a set of phased array adjustments to deliver a single high quality image.

In principal the same technology can be used to disrupt the focus of a laser weapon system.

This BTW is a classic defense contractor we-can-do-whatever-you-want (if you've got the money) sales
pitch. 

I smell a trawl for R&D money.
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 TBC. Forward looking statements. T&C apply. "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline Star One

  • Senior Member
  • *****
  • Posts: 13457
  • UK
  • Liked: 3729
  • Likes Given: 220
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #485 on: 01/16/2017 05:49 pm »
It does demonstrate that BAE have brought their way into REL purely for the defence applications of the technology. I am increasingly convinced that at this time they have little to no interest in its civilian applications.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 9902
  • Everyplaceelse
  • Liked: 2312
  • Likes Given: 12824
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #486 on: 01/16/2017 06:09 pm »
It does demonstrate that BAE have brought their way into REL purely for the defence applications of the technology. I am increasingly convinced that at this time they have little to no interest in its civilian applications.
It's a PR video. But we know BAE has no civilian interests. It's all defense or government related. No general customers like a normal business.
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 TBC. Forward looking statements. T&C apply. "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Online adrianwyard

  • Full Member
  • ****
  • Posts: 1100
  • Liked: 308
  • Likes Given: 348
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #487 on: 01/16/2017 06:18 pm »
The cynic in me wonders if BAE invested in REL in part to give it generic high-tech credibility - so that it's more likely to win any far-future R&D money, even when the research is not at all SABRE related...

Offline momerathe

  • Full Member
  • *
  • Posts: 150
  • Liked: 73
  • Likes Given: 36
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #488 on: 01/16/2017 09:34 pm »
It does demonstrate that BAE have brought their way into REL purely for the defence applications of the technology. I am increasingly convinced that at this time they have little to no interest in its civilian applications.

I think that's a fairly common opinion. They know which side their bread is buttered, after all. However, if that funds SABRE to the point where there is a working, flying engine then I think hope that will open the way to civilian applications.
thermodynamics will get you in the end

Offline CameronD

  • Senior Member
  • *****
  • Posts: 2246
  • Melbourne, Australia
    • Norton Consultants
  • Liked: 795
  • Likes Given: 512
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #489 on: 01/16/2017 09:48 pm »
It does demonstrate that BAE have brought their way into REL purely for the defence applications of the technology. I am increasingly convinced that at this time they have little to no interest in its civilian applications.

I think that's a fairly common opinion. They know which side their bread is buttered, after all. However, if that funds SABRE to the point where there is a working, flying engine then I think hope that will open the way to civilian applications.

That's a reasonable expectation.  Historically, there have been many technologies requiring significant funding that have been developed and refined for military purposes and then 'converted' to civilian use. GPS is perhaps the most notable nowadays, but really the same thing has been happening since the invention of gunpowder.
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.

Offline Star One

  • Senior Member
  • *****
  • Posts: 13457
  • UK
  • Liked: 3729
  • Likes Given: 220
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #490 on: 01/18/2017 08:58 pm »
And here's another video from BAE further to the one I posted a few days back.


Offline momerathe

  • Full Member
  • *
  • Posts: 150
  • Liked: 73
  • Likes Given: 36
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #491 on: 01/19/2017 07:24 am »
I make it a practice to never believe anyone who has "futurist" in their job title. ;)
thermodynamics will get you in the end

Offline knowles2

  • Full Member
  • *
  • Posts: 126
  • Liked: 28
  • Likes Given: 51
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #492 on: 02/03/2017 12:56 am »
It's not obvious what the advantages of such a platform would be over a satellite, but hey, at least the military vapourware peddlers haven't forgotten us ;).

Also, before watching that video I had no idea atmospheric lensing was a thing. Most references describe it as a problem for laser transmission, rather than a exploitable phenomenon though.
If military vapourware peddlers can get the funding to build Skylon so be it!!!

Laser power deflector shield, who knew that was even a diea.

Offline knowles2

  • Full Member
  • *
  • Posts: 126
  • Liked: 28
  • Likes Given: 51
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #493 on: 02/03/2017 12:58 am »
It does demonstrate that BAE have brought their way into REL purely for the defence applications of the technology. I am increasingly convinced that at this time they have little to no interest in its civilian applications.
It's a PR video. But we know BAE has no civilian interests. It's all defense or government related. No general customers like a normal business.
Not quite true, BAE has helped out the British Olympic cycle team on occasions. An I believe their cyber defence businesses does provide services to civilians businesses as well.
« Last Edit: 02/03/2017 01:02 am by knowles2 »

Offline alanr74

  • Member
  • Posts: 65
  • uk
  • Liked: 27
  • Likes Given: 34
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #494 on: 02/18/2017 07:34 am »
I noticed there is a 'thing' going on with Mark Thomas

https://www.aerosociety.com/events-calendar/the-development-and-potential-of-the-skylon-spaceplane-and-its-sabre-engines/
Quote
The Development and Potential of the Skylon Spaceplane and its Sabre Engines
22 February 2017
Derby Branch
Lecture

Mark Thomas, Chief Executive Officer, Reaction Engines Ltd will give a lecture to the RAeS Derby branch.

Offline t43562

  • Full Member
  • **
  • Posts: 285
  • UK
  • Liked: 158
  • Likes Given: 95
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #495 on: 02/21/2017 03:21 pm »
I noticed there is a 'thing' going on with Mark Thomas

https://www.aerosociety.com/events-calendar/the-development-and-potential-of-the-skylon-spaceplane-and-its-sabre-engines/
Quote
The Development and Potential of the Skylon Spaceplane and its Sabre Engines
22 February 2017
Derby Branch
Lecture

Mark Thomas, Chief Executive Officer, Reaction Engines Ltd will give a lecture to the RAeS Derby branch.

Does anyone know if the Derby branch lectures are open to non-members? I've tried them on their email without response yet.

I note that they have a newsletter which summarises lectures so at least we may get to read that at some point in the future:
https://www.aerosociety.com/Assets/Docs/About_Us/Branches/DerbyBranchNewsletter_Sept.pdf

I got my answer: yes they are open to the public. It's a bit of a long drive but I hope to do it.
« Last Edit: 02/22/2017 09:42 am by t43562 »

Offline SICA Design

  • Full Member
  • *
  • Posts: 179
  • UK
  • Liked: 43
  • Likes Given: 51
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #496 on: 02/22/2017 11:04 am »
Many thanks - I can't make it as I'm currently 170 miles away, but my wife will be attending and she's a great note taker!

Hopefully we'll learn how much focus is still on Skylon vs nearer-term defence apps for SABRE.

Offline t43562

  • Full Member
  • **
  • Posts: 285
  • UK
  • Liked: 158
  • Likes Given: 95
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #497 on: 02/22/2017 03:38 pm »
Am sitting in the car park waiting for it to begin. 100 miles for me :-).  Hope I can get something useful - I feel a lot of pressure now! :-D

....later.   I'm on my way home but I have an audio recording and I will post it - this time it's actually audible :-).   There wasn't anything shattering.  They are looking for an engine partner now - they needed BAE at the time and now they are at the point where they need Rolls or someone else.   They have some good contacts with Safran through Airbus Safran Launchers.  A large amount of money is being made available by the US DoD for testing the precooler in a hypersonic wind tunnel.

Apparently sealing the helium loop is hard. They don't know whether to work with an industrial partner to make their seals lighter or an aerospace partner to make their seals better.

They got 33 million in equity finance up to the BAE deal. Mark tomas said 23 million but the slides had 33 on them :/

They have a new management with people from Safran Leonardo Helicopters and so on who are much more focused on stepping stones rather than hoping to somehow get 10 billion dollars to do SSTO.

The heat in the helium loop can be used to generate a lot  of electrical power potentially. Military people like this a lot - why? Maybe lasers?

I have to go. Will update and upload the audio somewhere.
« Last Edit: 02/22/2017 10:21 pm by t43562 »

Offline knowles2

  • Full Member
  • *
  • Posts: 126
  • Liked: 28
  • Likes Given: 51
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #498 on: 02/22/2017 10:11 pm »
What did they need BAE for, regulatory hurdles in the US and the ability to the ball rolling with the DOD?

From the BAE video, it seems it lasers!

It such seem like this project is devolving into deal making rather than engine making.
« Last Edit: 02/22/2017 10:14 pm by knowles2 »

Offline t43562

  • Full Member
  • **
  • Posts: 285
  • UK
  • Liked: 158
  • Likes Given: 95
Re: The Reaction Engines Skylon Master Thread (6)
« Reply #499 on: 02/22/2017 10:17 pm »
The best answers will be in the actual recording:

This is the main bit of audio (59MB):
https://drive.google.com/open?id=0BwJNUxZZ7qItNWpmS3RiX2FKWG8

I had to start recording again during questions:
https://drive.google.com/open?id=0BwJNUxZZ7qItMWRTMDBMelJyRlU

Please let me know if there is any trouble with these links.

There are a couple of silences where everyone is watching videos of expendable rockets launching and then of nozzle-tests.

BTW, you might not be impressed but hurray for my old Nokia 808 Pureview which got this in a big noisy room.
« Last Edit: 02/22/2017 10:47 pm by t43562 »

Tags:
 

Advertisement NovaTech
Advertisement SkyTale Software GmbH
Advertisement Northrop Grumman
Advertisement
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1