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British aerospace company claims biggest engine advance since the jet

uk.reuters.com

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Re: British aerospace company claims biggest engine advance since the jet

#51

Post by rfugger »

bernardom wrote: post #14

From the article: "The company has deliberately avoided filing patents on its heat exchanger technology to avoid details of how it works - particularly the method for preventing the build-up of frost - becoming public." I would think that for something like this, the patent system would actually work fine. Anybody who tries to make this is going to be located in the US, Canada, Western Europe, or Japan. It's not like…

According to this BBC Four documentary (found in another comment)

https://www.youtube.com/watch?v=vZ_a21fPkYM

the engineers wanted to apply for a patent once the British government stopped funding their work, but the government classified their work as secret, preventing them from doing so.

EDITED TO ADD: Apparently the original secret classification expired in 1993, at which point they filed a patent which ended up being owned by Rolls Royce. Their current work circumvents that patent.

Re: British aerospace company claims biggest engine advance since the jet

#52

Post by marshray »

tocomment wrote: post #31
tocomment wrote: post #12

Does anyone have guesses on how the heat exchanger might work to prevent frost? Perhaps ultrasound?

How about dividing the heat exchanger into two sections? One section cools the air while the other section defrosts, and then alternate.

That was my first guess too. With that many pipes, they could have many sections which migrate the frosty sections down into the engine in waves.

Re: British aerospace company claims biggest engine advance since the jet

#53

Post by tvon »

drzaiusapelord wrote: post #35
mtgx wrote: post #5

Elon Musk was specifically asked about this technology when he was at Martin School last week. He didn't hear about it, but he seemed skeptical that it would work better than rockets. His response here: http://youtu.be/c1HZIQliuoA?t=48m55s SpaceX might still be the first one with a re-usable rocket if they finish the Raptor engine in 3 years. Plus, his could actually be used to land on Mars, while this can only be us…

Funny how this stuff works. The hot whiz-bang kid rewriting all the rules can become tomorrow's rent-seeking cronyistic old guard overnight. I wonder if a rocket vs sabre engine war is about to start. I hope so. Easier access to orbit and a 4 hour trip from NY to Tokyo would be pretty amazing.

I think you're forcing that narrative, the old guard does not tend to start out their statements with "I may have totally incorrect assumptions here, but...".

Re: British aerospace company claims biggest engine advance since the jet

#54

Post by pyre »

joonix wrote: post #45

Personally I'm always more intrigued by the prospect of getting around the world quicker. Making the world a smaller place, and more accessible to all, would do wonders for humanity.

You're missing the "cheaper" part that would be required to make it accessible to all.

Re: British aerospace company claims biggest engine advance since the jet

#55

Post by gvb »

krisoft wrote: post #39
gvb wrote: post #27

Earlier quoted context omitted.

My guess is that they inject liquid hydrogen into the hot air, so the cooling is actually done in free "air" rather than on the surface of a traditional metal heat exchanger - that would explain how they cool it so fast and help explain how they prevent frost in the heat exchanger during the cooling. This reformulates the problem into "how do we prevent the injectors from..." a) Melting (liquid hydrogen inside would…

Can't say anything about the plausibility of the scheme you mention, but the diagram in the BBC article contradicts it. There you can see that the primary cooling medium is liquid helium, in a closed circuit and a liquid nitrogen heat exchanger. Obviously the diagram can be just flawed, either as a disguise or unintentionally.

My bad, I did not read the much more informative BBC article before speculating.

Having a closed circuit nitrogen heat exchanger is interesting because it is a heat exchanger... you still need to get rid of the heat somewhere. For the demo (per the BBC), they evaporated some of the nitrogen to get rid of the heat, but that means you need excess nitrogen to boil off enough to reject the heat. I wonder how they plan to get rid of the heat in a real aircraft.

It also makes me wonder how they can have enough surface area to absorb the heat in the precooler but maintain enough airflow to generate the thrust they would need.

Re: British aerospace company claims biggest engine advance since the jet

#56

Post by stephengillie »

tompko wrote: post #26
mtgx wrote: post #5

Elon Musk was specifically asked about this technology when he was at Martin School last week. He didn't hear about it, but he seemed skeptical that it would work better than rockets. His response here: http://youtu.be/c1HZIQliuoA?t=48m55s SpaceX might still be the first one with a re-usable rocket if they finish the Raptor engine in 3 years. Plus, his could actually be used to land on Mars, while this can only be us…

> while this can only be useful where you still have atmosphere and oxygen The planned SABRE engine can act as a rocket as well closing the intake and using stored liquid oxygen so it would be capable of operating without an atmosphere and oxygen and landing on Mars.

Can it take off from Mars? In another HN thread a month ago, we discussed how Mars' atmosphere is so thin that a Cessna would need 747 wings and near Mach 1 velocity to take off.

Re: British aerospace company claims biggest engine advance since the jet

#57

Post by stcredzero »

lazyjones wrote: post #36

This is great news, but it also makes me a bit sad - because all this innovation died down in the 80's when everyone lost interest in the space race. We could be 30 years further down the road already and many of us probably won't live to see people setting foot on Mars.

I think many of us will.

Re: British aerospace company claims biggest engine advance since the jet

#58

Post by Create »

tocomment wrote: post #31
tocomment wrote: post #12

Does anyone have guesses on how the heat exchanger might work to prevent frost? Perhaps ultrasound?

How about dividing the heat exchanger into two sections? One section cools the air while the other section defrosts, and then alternate.

playing with pressure differences, thermodynamics, sections and annealing, you could think about freeze-drying while drinking your lyo coffee.

Re: British aerospace company claims biggest engine advance since the jet

#59

Post by stcredzero »

ChuckMcM wrote: post #50
stcredzero wrote: post #48

Earlier quoted context omitted.

Fuel (energy) cost is less than 1% of the cost to launch. The big costs are manpower, maintenance, and refurbishment.

That was the interesting takeaway from the Elon Musk talk about how cheap the fuel was compared to everything else. Having the Skylon be reusable then shifts some of the operational costs back to fuel. Of course a plane that can fly a Mach 5 and 100,000' has other uses, the most obvious one being the SR-71 replacement. Nothing like a bit of high speed aerial surveillance "right now" to help folks on the ground make b…

Yes, but having anything be reusable does that. If you can make up what you would have gained with Skylon by making the fuel tank 5% larger, then the opportunity cost of developing a radically new engine isn't worth it. Mach 5 does have other uses, though.

Re: British aerospace company claims biggest engine advance since the jet

#60

Post by stcredzero »

gvb wrote: post #55
krisoft wrote: post #39

Earlier quoted context omitted.

Can't say anything about the plausibility of the scheme you mention, but the diagram in the BBC article contradicts it. There you can see that the primary cooling medium is liquid helium, in a closed circuit and a liquid nitrogen heat exchanger. Obviously the diagram can be just flawed, either as a disguise or unintentionally.

My bad, I did not read the much more informative BBC article before speculating. Having a closed circuit nitrogen heat exchanger is interesting because it is a heat exchanger... you still need to get rid of the heat somewhere. For the demo (per the BBC), they evaporated some of the nitrogen to get rid of the heat, but that means you need excess nitrogen to boil off enough to reject the heat. I wonder how they plan to…

I wonder how they plan to get rid of the heat in a real aircraft.

Boil hydrogen. (All there for reading or watching.)

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