Reaction Engines’ Sabre Rocket Engine Demo Core Passes Review
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Reaction Engines’ Sabre Rocket Engine Demo Core Passes Review
Good to read that progress is being made.
Intro to an article on Aviation Week:-
Intro to an article on Aviation Week:-
The demonstrator core of Reaction Engines’ air-breathing Sabre rocket propulsion system has successfully passed a preliminary design review held in collaboration with the UK Space Agency and European Space Agency.
The assessment clears the way for a follow-on critical design review and the subsequent development and test of the core at a newly built facility in Westcott, England, in 2020. The complete engine, which will ultimately build on the core to incorporate a pre-cooler, rocket engine and ramjet, is designed to provide air-breathing thrust from the runway to Mach 5 and beyond for hypersonic aircraft and, in rocket mode, low-cost access to space.
The assessment clears the way for a follow-on critical design review and the subsequent development and test of the core at a newly built facility in Westcott, England, in 2020. The complete engine, which will ultimately build on the core to incorporate a pre-cooler, rocket engine and ramjet, is designed to provide air-breathing thrust from the runway to Mach 5 and beyond for hypersonic aircraft and, in rocket mode, low-cost access to space.
The current cost of a 'standard' Falcon 9 FT launch books at $50 million. The stated ambition is to get that figure below $10 million through reusability. Seventeen years ago, SpaceX didn't even exist. Now, they have approximately 65 - 70% of the commercial launch market, with all of the economies of scale which that brings. I, for one, wouldn't bet against them achieving that goal. Everyone else is looking like an 'also ran', and I see nothing on the horizon likely to change that.
The difference being, that you can go and launch your payload on several pure rocket launchers today but, your payload will have evaporated before this "spaceplane" ever exists. 
Like the Stirling engine, the efficiencies claimed for this regenerative heat cycle and cryogenic cooled, air-compressing, condensing and breathing/pure LOX/LH2 variable cycle rocket engine do not stack-up. The theoretical efficiency factors do not translate into the weight-limited reality that would be needed to make it competitive in orbital operation. The plant required to achieve the theoretical efficiencies is worthy of a ground based Nuclear powerstation.
Somehow, it is proposed that the efficiency of wing-borne lift within the atmosphere, burning Hydrogen fuel with a small amount of ingested air, cooled and compressed by energy from carrying extra liquid Hydrogen fuel that also provides cryogenic cooling of the air through bulky heat exchangers, will provide some earth shattering increase in efficiency. Of course, this also ignores the extra weight of the wing-borne structure and it's aerodynamic controls, the extra weight of the complex engines that have to be lifted all through the flight and reentry, the extra Hydrogen fuel/coolant to operate the air-breathing rocket, the take-off and landing apparatus, the extra propellant burn during the slow ascent and, the deadweight of the additional propellants that are needed to accelerate the relatively slow spaceplane to orbit after the interface between wing-borne/air breathing and the pure rocket/ballistic operation above the atmosphere, compared to a non wing-borne multi stage pure rocket.
There is also the question about the construction of a large spaceplane that is intended to be re-used, the weight of the structure to survive reentry, heating, flight loads and landing. Oh yes, landing. On a runway, like the takeoff?
However, the benefit of wing-borne lifting a ballistic rocket to some altitude and speed for launch to orbit (like the Pegasus launch system) does have some performance advantages but, of course, there are the practicalities of size.
Now, there are certainly interesting possibilities for high altitude atmospheric flight but, I reckon that the the multi stage rocket has got orbital lifting well and truly wrapped up for generations.
OAP
Like the Stirling engine, the efficiencies claimed for this regenerative heat cycle and cryogenic cooled, air-compressing, condensing and breathing/pure LOX/LH2 variable cycle rocket engine do not stack-up. The theoretical efficiency factors do not translate into the weight-limited reality that would be needed to make it competitive in orbital operation. The plant required to achieve the theoretical efficiencies is worthy of a ground based Nuclear powerstation.
Somehow, it is proposed that the efficiency of wing-borne lift within the atmosphere, burning Hydrogen fuel with a small amount of ingested air, cooled and compressed by energy from carrying extra liquid Hydrogen fuel that also provides cryogenic cooling of the air through bulky heat exchangers, will provide some earth shattering increase in efficiency. Of course, this also ignores the extra weight of the wing-borne structure and it's aerodynamic controls, the extra weight of the complex engines that have to be lifted all through the flight and reentry, the extra Hydrogen fuel/coolant to operate the air-breathing rocket, the take-off and landing apparatus, the extra propellant burn during the slow ascent and, the deadweight of the additional propellants that are needed to accelerate the relatively slow spaceplane to orbit after the interface between wing-borne/air breathing and the pure rocket/ballistic operation above the atmosphere, compared to a non wing-borne multi stage pure rocket.
There is also the question about the construction of a large spaceplane that is intended to be re-used, the weight of the structure to survive reentry, heating, flight loads and landing. Oh yes, landing. On a runway, like the takeoff?
However, the benefit of wing-borne lifting a ballistic rocket to some altitude and speed for launch to orbit (like the Pegasus launch system) does have some performance advantages but, of course, there are the practicalities of size.
Now, there are certainly interesting possibilities for high altitude atmospheric flight but, I reckon that the the multi stage rocket has got orbital lifting well and truly wrapped up for generations.
OAP
Last edited by Onceapilot; 16th Mar 2019 at 17:53.
Onceapilot:
ESA think it might. The US AFRL think it might. The people involved are actual rocket scientists one of whom also worked at JET on nuclear fusion. Weight limiting is the whole point because LOX is very dense and they aim to have to carry less.
The whole point of their cycle is the way it uses energy that the LACE (Liquid Air Cycle Engine) concept wasted. The innovation is the thermodynamic cycle and the very lightweight heat exchangers that enable it.
You're implying that these people can't do basic sums about weight which if you think about it would be quite unlikely. In fact they are an engine company and their reason for designing a notional spaceplace (Skylon) was to demonstrate that the sums in fact did work out and that the weight of the vehicle was amply compensated for by the reduction in the amount of LOX that it had to carry. On top of that the US AFRL has done work on other concepts with smaller versions of the same engine and a TSTO orbit configuration and considered it feasible.
That depends on many factors including whether they can recover upper stages. It also means that you indeed need a landing pad in a place where you can accept the risk of a rocket falling somewhere perhaps not exactly where it should. Rockets are very unreliable in comparison to aircraft. If totally reused they might get to a much higher level but they're not thus far etc.
Skylon's cost has always presented problems because it was a big upfront investment. With cost of that investment entirely laid at the door of one vehicle it would compete with a fully reusable rocket and the issue is why would anyone go to that effort to be "as good". On the other hand if you start using the SABRE engine in military aircraft and perhaps start with smaller TSTO spaceplanes and if there are numerous spinoffs for the heat exchanger technology in conventional jet engines and .... nuclear submarines or whatever... then the economics could see quite a big change.
So the real problem is whether the market will be big enough to support all these companies. It might be growing but I don't think that's easy to predict. The proposed internet satellite constellations might be the way to have enough launches to justify the many ongoing developments by various companies and I think the SpaceX one is important to their plans for making launches cheaper but I wonder if there are slightly too many of those constellations in planning.
Like the Stirling engine, the efficiencies claimed for this regenerative heat cycle and cryogenic cooled, air-compressing, condensing and breathing/pure LOX/LH2 variable cycle rocket engine do not stack-up. The theoretical efficiency factors do not translate into the weight-limited reality that would be needed to make it competitive in orbital operation. The plant required to achieve the theoretical efficiencies is worthy of a ground based Nuclear powerstation.
The whole point of their cycle is the way it uses energy that the LACE (Liquid Air Cycle Engine) concept wasted. The innovation is the thermodynamic cycle and the very lightweight heat exchangers that enable it.
Somehow, it is proposed that the efficiency of wing-borne lift within the atmosphere, burning Hydrogen fuel with a small amount of ingested air, cooled and compressed by energy from carrying extra liquid Hydrogen fuel that also provides cryogenic cooling of the air through bulky heat exchangers, will provide some earth shattering increase in efficiency. Of course, this also ignores the extra weight of the wing-borne structure and it's aerodynamic controls, the extra weight of the complex engines that have to be lifted all through the flight and reentry, the extra Hydrogen fuel/coolant to operate the air-breathing rocket, the take-off and landing apparatus, the extra propellant burn during the slow ascent and, the deadweight of the additional propellants that are needed to accelerate the relatively slow spaceplane to orbit after the interface between wing-borne/air breathing and the pure rocket/ballistic operation above the atmosphere, compared to a non wing-borne multi stage pure rocket.
There is also the question about the construction of a large spaceplane that is intended to be re-used, the weight of the structure to survive reentry, heating, flight loads and landing. Oh yes, landing. On a runway, like the takeoff?
However, the benefit of wing-borne lifting a ballistic rocket to some altitude and speed for launch to orbit (like the Pegasus launch system) does have some performance advantages but, of course, there are the practicalities of size.
Now, there are certainly interesting possibilities for high altitude atmospheric flight but, I reckon that the the multi stage rocket has got orbital lifting well and truly wrapped up for generations.
However, the benefit of wing-borne lifting a ballistic rocket to some altitude and speed for launch to orbit (like the Pegasus launch system) does have some performance advantages but, of course, there are the practicalities of size.
Now, there are certainly interesting possibilities for high altitude atmospheric flight but, I reckon that the the multi stage rocket has got orbital lifting well and truly wrapped up for generations.
Skylon's cost has always presented problems because it was a big upfront investment. With cost of that investment entirely laid at the door of one vehicle it would compete with a fully reusable rocket and the issue is why would anyone go to that effort to be "as good". On the other hand if you start using the SABRE engine in military aircraft and perhaps start with smaller TSTO spaceplanes and if there are numerous spinoffs for the heat exchanger technology in conventional jet engines and .... nuclear submarines or whatever... then the economics could see quite a big change.
So the real problem is whether the market will be big enough to support all these companies. It might be growing but I don't think that's easy to predict. The proposed internet satellite constellations might be the way to have enough launches to justify the many ongoing developments by various companies and I think the SpaceX one is important to their plans for making launches cheaper but I wonder if there are slightly too many of those constellations in planning.
Thanks for your reply t43562.
So, let us cut to the chase....There are Military possibilities for partial/air breathing Scramjet etc high altitude/high speed vehicles that must incorporate cryogenic elements. However, the technologies are underdeveloped, expensive and not yet crucial so, it gets back-burnered and funded from misdirected technology development, and sci-fi spaceplane smoke and mirror funding.
Good luck with your (notional) spaceplane.
BTW, Charge air cooling of subsonic commercial aircraft gas turbines is already proven to be inefficient, even if the heat exchanger was weightless.
OAP
So, let us cut to the chase....There are Military possibilities for partial/air breathing Scramjet etc high altitude/high speed vehicles that must incorporate cryogenic elements. However, the technologies are underdeveloped, expensive and not yet crucial so, it gets back-burnered and funded from misdirected technology development, and sci-fi spaceplane smoke and mirror funding.
Good luck with your (notional) spaceplane.
BTW, Charge air cooling of subsonic commercial aircraft gas turbines is already proven to be inefficient, even if the heat exchanger was weightless.
OAP
https://www.bbc.co.uk/news/science-environment-47832920
https://www.reactionengines.co.uk/ne...eat-conditions
They're apparently at Mach 3.3 conditions and ramping up to Mach 5 conditions and think it's all going better than expected so far.
https://www.reactionengines.co.uk/ap..._Animation.mp4
UK engineers developing a novel propulsion system say their technology has passed another key milestone.
The Sabre air-breathing rocket engine is designed to drive space planes to orbit and take airliners around the world in just a few hours. To work, it needs to manage very high temperature airflows, and the team at Reaction Engines Ltd has developed a heat-exchanger for the purpose.
This key element has just demonstrated an impressive level of performance. It has shown the ability to handle the simulated conditions of flying at more than three times the speed of sound. It did this by successfully quenching a 420C stream of gases in less than 1/20th of a second.
...
The Sabre air-breathing rocket engine is designed to drive space planes to orbit and take airliners around the world in just a few hours. To work, it needs to manage very high temperature airflows, and the team at Reaction Engines Ltd has developed a heat-exchanger for the purpose.
This key element has just demonstrated an impressive level of performance. It has shown the ability to handle the simulated conditions of flying at more than three times the speed of sound. It did this by successfully quenching a 420C stream of gases in less than 1/20th of a second.
...
In the recent tests, the compact precooler achieved all test objectives and achieved 1.5 MW of heat transfer, the equivalent to the energy demand of 1,000 homes; successfully cooling incoming air from a temperature at which hot steel starts to glow. The tests are the first phase in an extensive test programme which will see the precooler test article (HTX) exposed to high-temperature airflow conditions in excess of the 1,000°C (~1800°F) expected during Mach 5 hypersonic flight.
The significant testing milestone occurred at Reaction Engines’ recently commissioned TF2 test facility located at the Colorado Air and Space Port, US. The TF2 test facility has been constructed by Reaction Engines to undertake ground based ‘hot’ testing of its precooler technology. The technology has already passed an extensive range of tests in the UK where its performance was fully validated at ambient air temperatures.
The significant testing milestone occurred at Reaction Engines’ recently commissioned TF2 test facility located at the Colorado Air and Space Port, US. The TF2 test facility has been constructed by Reaction Engines to undertake ground based ‘hot’ testing of its precooler technology. The technology has already passed an extensive range of tests in the UK where its performance was fully validated at ambient air temperatures.
https://www.reactionengines.co.uk/ap..._Animation.mp4
Last edited by t43562; 8th Apr 2019 at 11:56. Reason: add a link to a video that explains.
So, the BS about "spaceplane" continues. I will not book my ticket. As I have said, this engine project has a Military purpose. The fact that todays general population can be deceived is unsurprising.
OAP
As I have said, this engine project has a Military purpose. The fact that todays general population can be deceived is unsurprising. OAP
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Reaction engines
This concept was around when I worked (I retired 1996!). The UK government
was not keen, if I remember correctly it was made 'secret'. No one else could build it.
was not keen, if I remember correctly it was made 'secret'. No one else could build it.
Ecce Homo! Loquitur...
http://aviationweek.com/aircraft-pro...ypersonic-testReaction Engines Precooler Passes Hypersonic Test
Reaction Engines’ precooler has successfully run at Mach 5 temperatures, validating for the first time the capability of the novel heat exchanger design to operate at hypersonic flight conditions for atmospheric and space access applications.
The breakthrough test is pivotal to Reaction’s goal of using the lightweight heat exchanger (HTX) to boost high-speed turbojets for supersonic and hypersonic vehicles as well as for developing the company’s Synergistic Air-Breathing Rocket Engine (Sabre), which is targeted at low-cost, repeatable access to space.
Forming the culmination of a DARPA contract awarded in 2017, the Mach 5 run took place in the second week of October at the company’s TF2 test facility at the Colorado Air and Space Port near Watkins. Established on an all-new site just 22 months ago, the high-speed test comes seven months after the heat exchanger demonstrated operation at supersonic conditions equal to Mach 3.3. Heated air for the tests is generated by a General Electric J79, which operated at military power for the supersonic runs and in maximum afterburner for the tests up to Mach 5.
“We had high confidence but, until these tests over the past six months, there was just an assumption this technology would work at these high temperatures because there was no way to test it. So, I’m very glad it came off,” says Adam Dissel, president of Reaction Engines. Although initial tests in the UK in 2012 using a Rolls-Royce Viper turbojet demonstrated the ability of the HTX to chill air from ambient to under -120C (-184F), the larger-scale evaluations in the U.S. were viewed as the true acid test. “Taking the whole device up to these high temperatures as part of an integrated system is quite a design challenge,” he adds.
Describing the test result as a “major moment in the development of a breakthrough in aerospace technology,” Reaction Engines CEO Mark Thomas says: “We are seeing significant interest from a range of potential customers and technology partners.”.........
Following the activation of the afterburner system on the J79, the team took a build-up approach toward hitting the high Mach target. “Through early summer, we tested multiple points of the envelope, eventually running up to about Mach 4.3. We tested at various airflow rates with varying coolant rates of helium mass flow passing through the precooler,” says Dissel. The approach yielded “a good understanding of the physics and the air-pressure drop across the matrix as it transitions across the precooler,” he adds. The results also indicate the HTX responds quickly to variable airflow conditions. “The precooler has behaved amazingly well,” Dissel says. “It adapts to changing flow nearly instantly, so that was good to see. It’s part of a function of how light it is, so the precooler is not relying on thermal inertia to survive.”
By the time tests got to Mach 4.3 levels, however, the group realized that the test infrastructure was approaching heating limits before the precooler could reach its planned test condition. “The challenge we have had on the facility side was tricking it into thinking it’s flying on a Mach 5 aircraft. To ensure we had the right condition, we took a couple of months to make some upgrades and added insulation blankets to reduce the heat transfer into the walls of the airflow ducts and plenum,” he adds. The upgrade, which also involved increasing the mass flow of the helium cooling circuit, made sure “we were ready to go for gold on the max condition,” Dissel notes.......
Reaction Engines’ precooler has successfully run at Mach 5 temperatures, validating for the first time the capability of the novel heat exchanger design to operate at hypersonic flight conditions for atmospheric and space access applications.
The breakthrough test is pivotal to Reaction’s goal of using the lightweight heat exchanger (HTX) to boost high-speed turbojets for supersonic and hypersonic vehicles as well as for developing the company’s Synergistic Air-Breathing Rocket Engine (Sabre), which is targeted at low-cost, repeatable access to space.
Forming the culmination of a DARPA contract awarded in 2017, the Mach 5 run took place in the second week of October at the company’s TF2 test facility at the Colorado Air and Space Port near Watkins. Established on an all-new site just 22 months ago, the high-speed test comes seven months after the heat exchanger demonstrated operation at supersonic conditions equal to Mach 3.3. Heated air for the tests is generated by a General Electric J79, which operated at military power for the supersonic runs and in maximum afterburner for the tests up to Mach 5.
“We had high confidence but, until these tests over the past six months, there was just an assumption this technology would work at these high temperatures because there was no way to test it. So, I’m very glad it came off,” says Adam Dissel, president of Reaction Engines. Although initial tests in the UK in 2012 using a Rolls-Royce Viper turbojet demonstrated the ability of the HTX to chill air from ambient to under -120C (-184F), the larger-scale evaluations in the U.S. were viewed as the true acid test. “Taking the whole device up to these high temperatures as part of an integrated system is quite a design challenge,” he adds.
Describing the test result as a “major moment in the development of a breakthrough in aerospace technology,” Reaction Engines CEO Mark Thomas says: “We are seeing significant interest from a range of potential customers and technology partners.”.........
Following the activation of the afterburner system on the J79, the team took a build-up approach toward hitting the high Mach target. “Through early summer, we tested multiple points of the envelope, eventually running up to about Mach 4.3. We tested at various airflow rates with varying coolant rates of helium mass flow passing through the precooler,” says Dissel. The approach yielded “a good understanding of the physics and the air-pressure drop across the matrix as it transitions across the precooler,” he adds. The results also indicate the HTX responds quickly to variable airflow conditions. “The precooler has behaved amazingly well,” Dissel says. “It adapts to changing flow nearly instantly, so that was good to see. It’s part of a function of how light it is, so the precooler is not relying on thermal inertia to survive.”
By the time tests got to Mach 4.3 levels, however, the group realized that the test infrastructure was approaching heating limits before the precooler could reach its planned test condition. “The challenge we have had on the facility side was tricking it into thinking it’s flying on a Mach 5 aircraft. To ensure we had the right condition, we took a couple of months to make some upgrades and added insulation blankets to reduce the heat transfer into the walls of the airflow ducts and plenum,” he adds. The upgrade, which also involved increasing the mass flow of the helium cooling circuit, made sure “we were ready to go for gold on the max condition,” Dissel notes.......
But where does the heat go after being taken out of the incoming airflow? If it transfers to liquid helium in the pre-cooler, what do they do with a pile of hot helium?