3 ms·

Rotating Detonation Engine of some kind? I've had a bit of a thrust-crush on that configuration since I heard they were working on the fluid dynamics to make th

Rotating Detonation Engine of some kind? I've had a bit of a thrust-crush on that configuration since I heard they were working on the fluid dynamics to make them work. Pulse Detonation Engines are cool and all, but no one wants a kilometer of tailpipe hanging off the ass end of their vehicle. That fluid problem really is the Achille's heel of RDE, because it requires such a clean airflow in the thing, in order to synchronize the blast waves. The longest burns to date, so far as I know, have been with LOX.

ethbr1 3y ago
They look otherworldly too. Recent NASA test: https://m.youtube.com/watch?v=UShD03eG9IU https://m.youtube.com/watch?v=UShD03eG9IU
- nielsbot 3y ago
  Was this a destructive test? Thing looks like it destroyed itself. (What's with the foil just flying all over the place?)
  - ridgeguy 3y ago
    Some of the instrumentation wire harnesses were wrapped in foil, which got ripped off by air currents driven by the exhaust plume. Foil wraps shield against heating by IR radiation from the plume. It's cheap but effective.
  - MilStdJunkie 3y ago
    The sound from these things can literally tear other nearby assemblies apart. Aside from the "clean flow" problem, this is another gigantic engineering hurdle to scaling these things up to a larger size. There's such a thing as too powerful.
nielsbot 3y ago
> no one wants a kilometer of tailpipe hanging off the ass end of their vehicle speak for yourself
JumpCrisscross 3y ago
> Rotating Detonation Engine of some kind? No, if only by the sound. By the way, what happened to SABRE [1]. Slowly plugging along, or a victim of Brexit? [1] https://en.wikipedia.org/wiki/SABRE_(rocket_engine)#History https://en.wikipedia.org/wiki/SABRE_(rocket_engine)#History
- mattashii 3y ago
  Most "news articles" on the company website over the past year were joint projects from spinoff technologies and corporate rewards, with the most exciting things being them raising 40 million last year. In the meantime, I've noticed that another company "Hermeus" is building on similar concept engines to be used on their hypersonic planes, though currently they seem to be targeting modified versions of existing jet engines (changing the compressor while keeping combustion chamber intact), not a whole new model of jet engine.

ethbr1 3y ago

They look otherworldly too. Recent NASA test: https://m.youtube.com/watch?v=UShD03eG9IU https://m.youtube.com/watch?v=UShD03eG9IU

nielsbot 3y ago
Was this a destructive test? Thing looks like it destroyed itself. (What's with the foil just flying all over the place?)
- ridgeguy 3y ago
  Some of the instrumentation wire harnesses were wrapped in foil, which got ripped off by air currents driven by the exhaust plume. Foil wraps shield against heating by IR radiation from the plume. It's cheap but effective.
- MilStdJunkie 3y ago
  The sound from these things can literally tear other nearby assemblies apart. Aside from the "clean flow" problem, this is another gigantic engineering hurdle to scaling these things up to a larger size. There's such a thing as too powerful.

nielsbot 3y ago

> no one wants a kilometer of tailpipe hanging off the ass end of their vehicle speak for yourself

JumpCrisscross 3y ago

> Rotating Detonation Engine of some kind? No, if only by the sound. By the way, what happened to SABRE [1]. Slowly plugging along, or a victim of Brexit? [1] https://en.wikipedia.org/wiki/SABRE_(rocket_engine)#History https://en.wikipedia.org/wiki/SABRE_(rocket_engine)#History

mattashii 3y ago
Most "news articles" on the company website over the past year were joint projects from spinoff technologies and corporate rewards, with the most exciting things being them raising 40 million last year. In the meantime, I've noticed that another company "Hermeus" is building on similar concept engines to be used on their hypersonic planes, though currently they seem to be targeting modified versions of existing jet engines (changing the compressor while keeping combustion chamber intact), not a whole new model of jet engine.