Does that mean "piston engines" as in Super Constellation ? the irony, that would be. Should we bring back the Convair XC-99 or Lockheed Constitution ? Except with ammonia ?Ammonia is easier usable for combustion engines than for turbines
Does that mean "piston engines" as in Super Constellation ? the irony, that would be. Should we bring back the Convair XC-99 or Lockheed Constitution ? Except with ammonia ?Ammonia is easier usable for combustion engines than for turbines
Reaction Engines has officially formed a U.S. Board of Advisors! REI welcomes Dr. Mark Lewis and John “JV” Venable to the Reaction Engines Inc. U.S. Board of Advisors. They will be an excellent addition and provide us with strong guidance in our company strategy and growth
If you had any idea what heat transfer is about you would not be impressed by that rather simple tubular heat exchanger that they have been dancing around now for the past twenty years.Dagger, IMHO, REL is utterly unlike Theranos as their remarkable capillary heat exchanger has been proven to satisfaction of sponsors.
Also, REL does not exhibit the pathological behaviour of Theranos' management...
What are you talking about? Which post are you referring to?I challenged Dagger to provide evidence to support his claim that RE were switching LN2 for water. Of course nothing was produced.
I am worried that most members are not able to make up their minds correctly, when it comes to deciding whether to buy REL shares or not at or after the IPO, hence my warnings about REL's claims, and the fact that they produced almost nothing in 33 years.[.................] Most members are well able to make up their minds without such tricks, I think !
2. No they did not.
That "hypersonic" test was an even bigger farce. All they did was blow 1000 oC gas (jet engine exhaust) into a precooler that was cooled by atmospheric water inside the tubes. I don't think that the metal of the precooler got any warmer than 250 oC at the "hot" side and not colder than 100 oC at the "cold" side, while the pressure inside the tubes was only atmospheric. A far cry from the conditions the precooler metal would experience during actual hypersonic flight, which I estimate to be 950 oC at the hot side, -200 oC at the cold side, 200 bar inside, if the air would be cooled to -150 oC.
This test was just keeping up appearances. It had nothing to do with hypersonic.
Maybe some people should reread my previous posts.Everyone who knows why it could or could not work should know enough boundary conditions for his judgment.
Yes, icing is always a problem for engines which fly through humid air at freezing temperatures, whether it be on the way up, down or cruise. Remember SABRE is intended as a ground-to-orbit powerplant, so it is going to spend time in that regime at some point. Also, the stratosphere may have a low density, but it can still have a high relative humidity and an awful lot flows through an engine at high speeds. You don't need much ice to break a delicate microtube at those speeds.Well, is icing even such a serious concern for the very specific application this heat exchanger is intended for? I mean, absolute moisture content of stratospheric air (which is where the REL engine cycle would be operating in air-breathing mode) has to be vanishingly low compared to sea level, as a gut instinct?
Another approach could be switching the direction of the air flow trough the heat exchanger (inside out to outside in and vise versa). The icing will only occure in the downstream section after the air is cooled below 0° C, by changing the direction of the air flow periodically, the ice will always be removed in split seconds. Since the air flow is allready slowed down before entering the heat exchanger, I don"t epect troubles with the tubes (which btw. are far more robust than ordinary coolers out of aluminium plates).The whole 33year and start up thing is being very miss represented. For 25years RE was a company with just 3 employees, obsessed with solving just one problem. This is where the Theranos comparison is utter tosh as their CEO was even that old when she started her scam. How many start up have a 25year long preparation behind them?
Theranos did everything inside their company with investor funds and was found to be fraud when they failed customers which were private citizens. The disappointed customers brought in the government regulators. With RE in Colorado the customer is the US government including their internal audit process. The US gov DRAPA sponsored hypersonic research conducted by RE in Colorado is reproducing the flow condition in a cryogenic heat exchanger at high Mach number. It’s frankly absurd to claim that such a purpose built facility conducting such a focused test could switch LN2 for water and the sponsor wouldn’t notice. .
Dagger you’ve again failed to supply any evidence of your alleged fraud.m
Maybe they’ve found a version of this and coated the tubes within the heat exchanger.
Anti-icing performance of hydrophobic material used for electromechanical drill applied in ice core drilling | Journal of Glaciology | Cambridge Core
Anti-icing performance of hydrophobic material used for electromechanical drill applied in ice core drilling - Volume 66 Issue 258www.cambridge.org
Not possible with the REL design, simply look at photos of that precooler and at the minimal distance between the tubes. Look also how it is supposed to be installed inside SABRE engine and the direction of air flow.Is de-icing really impossible, or could it be done e.g., by switching of sections of the heat exchanger periodically? They might also use a device to scrap of the ice from the tubes or they might use something else which we might not know
That can't be correct. They started building that precooler model already 20 years ago.For 25years RE was a company with just 3 employees, obsessed with solving just one problem.
The "customers which were private citizens" (you mean shareholders?) were not disappointed until about 2015. The Theranos stock price went very high and they were very happy, but then an investigative journalist spoiled the party by publicly questioning what Theranos was really doing.Theranos did everything inside their company with investor funds and was found to be fraud when they failed customers which were private citizens. The disappointed customers brought in the government regulators. With RE in Colorado the customer is the US government including their internal audit process.
There is nothing hypersonic going on by RE in Colorado, no high Mach number and nothing cryogenic.The US gov DARPA sponsored hypersonic research conducted by RE in Colorado is reproducing the flow condition in a cryogenic heat exchanger at high Mach number. It’s frankly absurd to claim that such a purpose built facility conducting such a focused test could switch LN2 with water and the sponsor wouldn’t notice.
Not possible with the REL design, look again at photos of that precooler and at the minimal distance between the tubes. Look again how it is supposed to be installed inside SABRE engine and the direction of air flow.Another approach could be switching the direction of the air flow trough the heat exchanger (inside out to outside in and vise versa). The icing will only occure in the downstream section after the air is cooled below 0° C, by changing the direction of the air flow periodically, the ice will always be removed in split seconds.
Does that mean "piston engines" as in Super Constellation ? the irony, that would be. Should we bring back the Convair XC-99 or Lockheed Constitution ? Except with ammonia ?Ammonia is easier usable for combustion engines than for turbines
I just proposed some ways it might have been done or not, not all of their sketches need to show the truth. Anyway, I would be intrested on how they originally intended to deal with the icing problem...Not possible with the REL design, simply look at photos of that precooler and at the minimal distance between the tubes. Look also how it is supposed to be installed inside SABRE engine and the direction of air flow.Is de-icing really impossible, or could it be done e.g., by switching of sections of the heat exchanger periodically? They might also use a device to scrap of the ice from the tubes or they might use something else which we might not know
That can't be correct. They started building that precooler model already 20 years ago.For 25years RE was a company with just 3 employees, obsessed with solving just one problem.
The "customers which were private citizens" (you mean shareholders?) were not disappointed until about 2015. The Theranos stock price went very high and they were very happy, but then an investigative journalist spoiled the party by publicly questioning what Theranos was really doing.Theranos did everything inside their company with investor funds and was found to be fraud when they failed customers which were private citizens. The disappointed customers brought in the government regulators. With RE in Colorado the customer is the US government including their internal audit process.
As soon as an investigative journalist publicly starts questioning what REL is really doing that will also be the beginning of the end.
There is nothing hypersonic going on by RE in Colorado, no high Mach number and nothing cryogenic.The US gov DARPA sponsored hypersonic research conducted by RE in Colorado is reproducing the flow condition in a cryogenic heat exchanger at high Mach number. It’s frankly absurd to claim that such a purpose built facility conducting such a focused test could switch LN2 with water and the sponsor wouldn’t notice.
That test facility is just a big hair dryer blowing low speed hot air over a piece of some inconel alloy of which it's known already for decades that it can withstand that.
That DARPA falls for that is really shocking, hence my suspicion that the people who made that decission know little or nothing about heat transfer but were influenced by FOMO.
Not possible with the REL design, look again at photos of that precooler and at the minimal distance between the tubes. Look again how it is supposed to be installed inside SABRE engine and the direction of air flow.Another approach could be switching the direction of the air flow trough the heat exchanger (inside out to outside in and vise versa). The icing will only occure in the downstream section after the air is cooled below 0° C, by changing the direction of the air flow periodically, the ice will always be removed in split seconds.
How REL pretended to avoid freezing up the precooler is not a secret. They wrote and talked about it long time ago. In my professional judgement that is a joke.
I said it already several times (but fanboys prefer to ignore it) REL does not talk about -150 oC anymore on their website, or in the brochure that overscan posted in post #487 (see relevant page in attachment), but merely about cooling down to ambient, which is easy.
For 25years RE was a company with just 3 employees, obsessed with solving just one problem.
That can't be correct. They started building that precooler model already 20 years ago.
There is nothing hypersonic going on by RE in Colorado, no high Mach number and nothing cryogenic.
That test facility is just a big hair dryer blowing low speed hot air over a piece of some inconel alloy of which it's known already for decades that it can withstand that.
That DARPA falls for that is really shocking, hence my suspicion that the people who made that decission know little or nothing about heat transfer but were influenced by FOMO.
Do you expect us to dig through some 300 pfds to look for ..... what exactly?For 25years RE was a company with just 3 employees, obsessed with solving just one problem.
That can't be correct. They started building that precooler model already 20 years ago.
Yawn - So how about we look at some independent evidence?
U.K. Companies house filings;- 1989 to present day
REACTION ENGINES LIMITED filing history - Find and update company information - GOV.UK
REACTION ENGINES LIMITED - Free company information from Companies House including registered office address, filing history, accounts, annual return, officers, charges, business activityfind-and-update.company-information.service.gov.uk
So you agree that nothing hypersonic is going on by RE in Colorado, no high Mach number and nothing cryogenic.As for TF2, Yes I know there’s no gas traveling at hypersonic speed but that’s not the intent;- it’s reproducing the thermal/pressure/flow conditions within the HTX when the thing would be doing hypersonic speed…. A while ago I watched similar testing on ramjets and gas turbine core stages… it’s how we do things in aerospace… aka “an element test”.
A water pressure test, that's all. No "element test" for heat exchangers.Each year thousands of heat exchangers are designed and built all over the world for use in the process industry.
Are each of them tested to check whether they will perform as intended? No. The design correlations to determine the required size of an exchanger are known and there is no need to check them in a test facility.
Are each of them tested to check whether they can withstand the temperature that they will have to endure during actual operation? No. The materials of each exchanger are selected based on the mechanical design temperature and corrosivity (if applicable). The mechanical properties of each alloy are well known. There are codes and standards that govern the material selection as well as what tensile strength (safety margin included) to be used for wall thickness calculations. There is no need to test them again and again.
Are each of them tested to check whether they can withstand the pressure that they will have to endure during actual operation? Sort of. They are tested at 1.5 to 2 times the mechanical design pressure using cold water. That's all. A simple, cheap test that takes little time. No test of simultaneous occurrence of high temperature and high pressure. That is covered by the factor 1.5 to 2. Following the codes and standards is all a designer and manufacturer needs to do.
That is typical manager talk and moreover sounds like it was written by REL PR department: “Reaction Engines technology is world-class". What a joke.US Air Force partners with Reaction Engines on ‘high-Mach’ engine testing
The UK-based manufacturer specialises in managing the build-up of heat in a variety of aerospace functions, including hypersonic engines.www.flightglobal.com
Note “USAF FCT manager William Reed. “Reaction Engines technology is world-class and is a great fit for the FCT programme.”and “The US Air Force (USAF) is partnering with the UK’s Reaction Engines to improve the performance of hypersonic and near-hypersonic engines.”
I reckon everyone reading this is aware that Mr W Reed of the USAF knows more about this than we do.
Using Water for heat transfer of the charge cooler is nothing new and other Formula 1 teams (e.g. Ferrari) did the same. The cooler is (if not done by Mercedes themself) most likely a product from Mezzo (https://www.mezzotech.com/).How about that. Our own Calum Douglas is surely the man to ask - his day job is Mercedes F1 engine design. I just pinged him, fingers crossed.The cooler in question uses technology developed by a UK company called Reaction Engines, which is working on the development of air breathing rocket motors. These engines have a similar requirement to a turbocharged gasoline engine in that incoming charge air is compressed and needs cooling, but to a much higher degree. The engines are designed to hurtle through the air at five times the speed of sound, with this forward speed helping to ram air into the engine inlet, heating it to around 1000°C in the process. Reaction Engines had to develop what it calls a pre-cooler to drop this temperature back down to ambient levels, and it turns out the technology has lots of uses beyond rockets – including F1.The rocket tech behind Mercedes’ cutting-edge F1 coolers
A new compact air cooler, using rocket engine technology, could be the key to Mercedes' new slim F1 sidepods. Lawrence Butcher examines how it workswww.motorsportmagazine.com
Rocket technology to thank for Mercedes’ tiny sidepods – Symonds
Formula 1's chief technical officer, Pat Symonds, has provided some insight into how Mercedes has shrunk its sidepods down towww.motorsportweek.com
So you agree that nothing hypersonic is going on by RE in Colorado, no high Mach number and nothing cryogenic.
It’s not "reproducing the thermal/pressure/flow conditions within the HTX when the thing would be doing hypersonic speed" either. It's just blowing some smooth low speed hot air over a bunch of inconel tubes. No sonic shock waves that compress the air and heat it from ambient to 1000 oC, no residual turbulences that can hit the flimsy tubes. Just a perfectly safe show.
Cooling is not SABRE related?How does it come, that we talk so much about the pre-cooler???Cooling in general is not directly SABRE-related and belongs in a different topic. Since you are not reporting on work in the field, The Bar would be the appropriate forum here, thanks.To help with cooling perhaps
Reminds me of the J58 test stands at P&W Florida plant. They had a J75 engine (minus afterburner) feeding its exhaust into the front of the J58 to simulate the M3 / 80K inlet conditions. While the J58 AB could not operate at full power due to the partial oxygen depletion in the J75, the rest of the engine was seeing the appropriate temperatures and pressures for the test objectives.So you agree that nothing hypersonic is going on by RE in Colorado, no high Mach number and nothing cryogenic.
It’s not "reproducing the thermal/pressure/flow conditions within the HTX when the thing would be doing hypersonic speed" either. It's just blowing some smooth low speed hot air over a bunch of inconel tubes. No sonic shock waves that compress the air and heat it from ambient to 1000 oC, no residual turbulences that can hit the flimsy tubes. Just a perfectly safe show.
I'm not sure why exactly you think hypersonic flow would be required to reproduce the real operating conditions - it will NOT encounter hypersonic air, ever, in-flight either. As you say yourself, the very reason why the air flow is so hot (and why the HX is even there) is because it has been compressed - that is to say *decelerated* from hypersonic free-stream to subsonic - in the inlet. So long as you can supply enough air at the correct pressure and temperature by other means, there's absolutely no need to include the inlet and free-stream in a test setup concerning the HX only?
EDIT: In fact, if they are using jet engine exhaust as an air supply, the test is significantly more onerous than real operation in a key respect. There will be much higher water vapour content than in stratospheric air, which might in turn explain why they aren't cooling to below ambient.
Then they should simply have called it 'High Temperature Test Facility', but that would not have the same propaganda value.So you agree that nothing hypersonic is going on by RE in Colorado, no high Mach number and nothing cryogenic.
It’s not "reproducing the thermal/pressure/flow conditions within the HTX when the thing would be doing hypersonic speed" either. It's just blowing some smooth low speed hot air over a bunch of inconel tubes. No sonic shock waves that compress the air and heat it from ambient to 1000 oC, no residual turbulences that can hit the flimsy tubes. Just a perfectly safe show.
I'm not sure why exactly you think hypersonic flow would be required to reproduce the real operating conditions - it will NOT encounter hypersonic air, ever, in-flight either. As you say yourself, the very reason why the air flow is so hot (and why the HX is even there) is because it has been compressed - that is to say *decelerated* from hypersonic free-stream to subsonic - in the inlet. So long as you can supply enough air at the correct pressure and temperature by other means, there's absolutely no need to include the inlet and free-stream in a test setup concerning the HX only?
EDIT: In fact, if they are using jet engine exhaust as an air supply, the test is significantly more onerous than real operation in a key respect. There will be much higher water vapour content than in stratospheric air, which might in turn explain why they aren't cooling to below ambient.
I would not expect the helium to be cold enough to exhibit superfluid properties (which I assume is what you mean). At 1 atmosphere it is liquid below 4.2 K but does not become superfluid until around half that. No doubt RE's working pressure and temperature are somewhat higher. So a claimed performance significantly below the superfluid's calculated capabilities would be sensible enough.And, IIRC, this was compounded by Helium's 'super-critical' properties under those conditions.
To his surprise, REL seemed to have significantly under-stated the performance...