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Anyone able to provide some info on why this type of engine might be "better"? Is it's use likely to become widespread? Can it be scaled up to propel larger cra

Anyone able to provide some info on why this type of engine might be "better"? Is it's use likely to become widespread? Can it be scaled up to propel larger craft?

dr_dshiv 4y ago
I assume because you can use (mini)nuclear explosions in deep space?
- numpad0 4y ago
  Detonation engines has nothing to do with nukes, it’s just a different way of burning fuel, in a detonation mode/regimen/whatever. Which is I suppose more violent and rapid and efficient, but much more finicky compared to conventional combustion method/type/phenomenon. Sort of like ramjet vs scramjet difference. “I guess that’s better, if you think it can be done, I don’t know though” thing.
  - dr_dshiv 4y ago
    But the valuable energy density of nuclear doesn’t have a combustion equivalent, right? Only explosions or slow burns.
    - numpad0 4y ago
      I believe nuclear “explosions” are slow burns too, just a sun in Earth’s atmosphere out of nowhere has to cause explosion-like phenomena, and equivalence with chemical explosion can be established. In vacuum it will be just a molten ball. This one uses continuously happening detonation along a circular path, and has little to do with those.
kortex 4y ago
RDEs are more efficient than regular rocket engines. Also, a big part of engineering rocket combustion chambers is balancing power with combustion instability, which can cause flame-out at best, and rapid unscheduled disassembly at worse. RDEs lean into that high energy stochiometric reaction to eke out more efficiency. Due to the tyranny of the rocket equation, even a modest increase in efficiency can greatly increase payload to orbit.
xeonmc 4y ago
Pushing on solid wall is more effective than pushing on air. Shockwaves are effectively momentarily solid air that you could push on. RDE basically uses shockwaves as turbine blades. (technically I should say "incompressible vs compressible" but you get the imagery)
handol 4y ago
The detonation produces higher pressure and temperature, causing higher exhaust gas velocities. More energy in the exhaust means more push from the same amount of propellant. About 15% more. The other yet to be realized in practice advantage is that by eliminating the compressor stages on a rocket engine its construction is simplified, and despite needing a much stronger combustion chamber, it could actually be lighter. If it can live up to more efficient, cheaper, and lighter then it will certainly see widespread use. There are bound to be issues with new larger designs, but nothing show stopping is expected.

Anyone able to provide some info on why this type of engine might be "better"? Is it's use likely to become widespread? Can it be scaled up to propel larger craft?

dr_dshiv 4y ago

I assume because you can use (mini)nuclear explosions in deep space?

numpad0 4y ago
Detonation engines has nothing to do with nukes, it’s just a different way of burning fuel, in a detonation mode/regimen/whatever. Which is I suppose more violent and rapid and efficient, but much more finicky compared to conventional combustion method/type/phenomenon. Sort of like ramjet vs scramjet difference. “I guess that’s better, if you think it can be done, I don’t know though” thing.
- dr_dshiv 4y ago
  But the valuable energy density of nuclear doesn’t have a combustion equivalent, right? Only explosions or slow burns.
  - numpad0 4y ago
    I believe nuclear “explosions” are slow burns too, just a sun in Earth’s atmosphere out of nowhere has to cause explosion-like phenomena, and equivalence with chemical explosion can be established. In vacuum it will be just a molten ball. This one uses continuously happening detonation along a circular path, and has little to do with those.

kortex 4y ago

RDEs are more efficient than regular rocket engines. Also, a big part of engineering rocket combustion chambers is balancing power with combustion instability, which can cause flame-out at best, and rapid unscheduled disassembly at worse. RDEs lean into that high energy stochiometric reaction to eke out more efficiency. Due to the tyranny of the rocket equation, even a modest increase in efficiency can greatly increase payload to orbit.

xeonmc 4y ago

Pushing on solid wall is more effective than pushing on air. Shockwaves are effectively momentarily solid air that you could push on. RDE basically uses shockwaves as turbine blades. (technically I should say "incompressible vs compressible" but you get the imagery)

handol 4y ago

The detonation produces higher pressure and temperature, causing higher exhaust gas velocities. More energy in the exhaust means more push from the same amount of propellant. About 15% more. The other yet to be realized in practice advantage is that by eliminating the compressor stages on a rocket engine its construction is simplified, and despite needing a much stronger combustion chamber, it could actually be lighter. If it can live up to more efficient, cheaper, and lighter then it will certainly see widespread use. There are bound to be issues with new larger designs, but nothing show stopping is expected.