Researchers develop new rocket-propulsion system (2020) | Hacker News Reader

Researchers develop new rocket-propulsion system (2020)

ucf.edu

27 pointszeristor15 comments

I fail to see how this was "revolutionary" even back in 2020.

The principle has been known since the Apollo-era when von Braun and his team discovered it by accident (rotating detonations destroyed the F1-engine's combustion chamber) and several teams across the globe have been working on it ever since.

There's prototypes of such engine running at the TU Berlin since at least 2017, for example, and the Łukasiewicz Research Network in Poland even launched a rocket using such engine last year. JAXA also did a successful engine test in space last year.

So a prototype back in 2020 doesn't sound novel or even revolutionary to anyone even remotely interested in rocketry. But alas, press releases being press releases again...

I fail to see how nuclear fusion is "revolutionary". The principles are simple and has been known for a century.

There's a difference between a natural process being harnessed using technology and claiming a breakthrough when there's extensive research and working devices that are are further ahead in terms of TRL already.

But I guess you know that and just wanted be snarky ¯\_(ツ)_/¯

Having working engine launched would be "revolutionary", but prototype of something that was already prototyped aint that.

But JAXA got one launched in 2021...

In my book it's revolutionary when things start .. revolving. So to you it's not revolutionary because this is old news, and to me it's too early to be revolutionary. I'd say, this rocket tech can potentially spell a revolution.

I think the revolutionary aspect of a rotation detonation engine is the "rotation" (i.e. continuous) part, not the "detonation" part. IMO, it is pretty novel.

They developed it - that's in the title. No one had sustained it before. It's all in the details, and they nailed it. Which makes it news?

Since there's no rocket in existence (as far as we know) that uses it for launching payloads it's revolutionary. Rockets are so large because they need enormous amounts of fuel to fulfill their mission. Making rocket engines more efficient cuts down on the fuel usage and reduces their size, or alternatively, increases mission flexibility.

"Combustion and Flame" has to be one of the best journal names out there.

A video by Scott Manley explaining what a rotating detonation engine means: https://www.youtube.com/watch?v=rG_Eh0J_4_s

Integza built one of these at home! He interviewed with some of the creators as well.

https://youtu.be/fRMMSyCcTDI

The upper limit of the velocity of the explosions is stated as 5600 mph, which is 2500 m/s, and less than the 3000 m/s exhaust velocity on a Falcon 9 engine. Why is this useful?

This speed of the detonation front has nothing to do with exhaust velocity. This is a replacement for the combustion chamber sort of.

The throat and nozzle accelerates the propellants.

If memory serves the Raptor 2 has a diminished ISP in order to improve peak thrust. They widened the throat in order to push more power through it.

Raptor also trades efficiency for durability.

Methane is much cleaner burning than kerosene (RP-1) and leaves no soot inside the engine. Important if you want to reuse it!

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