Posted on 04/08/2019 7:06:11 PM PDT by BenLurkin
Fans of supersonic flight have been yearning for a new way to break the sound barrier ever since Concorde stopped flying in 2003.
Now successful tests of a key part of an air-breathing rocket engine may have brought that dream a step closer to reality.
UK company Reaction Engines announced successful tests of a precooler on Monday, simulating conditions at Mach 3.3, or more than three times the speed of sound.
That's more than 50% faster than the cruising speed of Concorde -- which used to make the journey between New York and Paris in around 3.5 hours -- and matches the speed record of the fastest jet aircraft ever made, the Lockheed SR-71 Blackbird.
The precooler tests were part of the company's plans to develop the Synergetic Air-Breathing Rocket Engine (SABRE) engine and took place at a testing facility at the Colorado Air and Space Port in the United States.
At such high speeds, air flowing through the engine can reach incredibly high temperatures, which can potentially cause damage.
A precooler reduces the temperature of gases before they enter the core engine itself.
(Excerpt) Read more at cnn.com ...
The thermal gradients alone on those heat exchanger elements are very high. Tough to manage those thermal stresses and avoid cracking that would leak hydrogen.
I’ve got a lot of faith in these UK guys though. They’ve been at it awhile.
Common metals and alloys could not handle that kind of thermal stress. They must be using some exotic material to that kind of rapid temperature gradient.
I work in the electric power industry and we have strict heat up and cool down rates to prevent exceeding thermal stress limits.
That kind of cool down rate wouldn’t even be possible in our condenser. But of course, we don’t have liquid hydrogen or oxygen flowing through our tubes.
It’s U.K. not US. And while brits have their own national security interests; if Brexit ever does happen, such technology would be of enormous economic benefit.
Yea, and it’s fuel tanks leaked like a sieve on the ground until it got airborne and up to speed. And it needed special JP fuel with a really high ignition temp.
Isn’t this a scram jet?
Wonder what the un-simplified version looks like... ;)
No, a sramjet uses supersonic air for compression. Blackbird is more of a ramjet. Those spikes at the front of the nacelles along with by-pass doors, manage the SS airflow to bring it subsonic for the turbine to compress before combustion.
Nvermind. I was talking the 71 and you were talking about the new engine.
I havent delved into yet. Been busy.
The SR 71 increased about a foot in length at top speed, which created many problems.
That’s why it was skinned in titanium, too. At rest, on the runway, there were gaps in the skin. Some big enough you can put your fingers through.
“Sled Driver” from Brian Shul is an awesome look at what it takes to drive an SR-71.
I found it in PDF format, online, 2 years or so ago. Let me know if you want a link.
After reading everything again, I have come to the conclusion that the inlet is blocked off entirely before it ever gets into the transition phase, the precooler would otherwise be destroyed.
That would be the blocker door to the precooler/compressor. The inlet portion to the ramjet would remain open.
Thanks for the article. This is an excellent explanation of a combined cycle engine.
Sure, send it along. The SR 71 is one of the most fascinating planes of all time.
Of course, the most beautiful plane ever built is the Boeing 747.
https://www.dropbox.com/s/d2obrrulsyk90dd/Sled%20Driver%20%28Shul%29.pdf?dl=0
I was a fan of the SR-71, and the YF-12. To me, combined with the B-1 (Bone), and the B-2 Spirit, are the prettiest birds in the air.
There’s also a declassified Blackbird flight manual out there that makes for a very interesting read.
I hope they do not make the mistake of Boeing and Airbus with their faulty sensors or this plane will hit the earth at mach 3.3
“Note: Mach 25 is orbital, thus not reacting with atmospheric friction in the same way.”
Not really true. Re-entry conditions are Mach 25, 180 db, and 3000 degress f. Look at some pictures of the bottom of space shuttles. That must have been a wild ride back into the atmosphere even if it only lasted a couple of minutes.
Noted. Though full speed of a Mach 25 range, would not last the entire re-entry period, would it?
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