Questions regarding the design or design process for a propulsion system.
Questions tagged [engine-design]
416 questions
14
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1 answer
What is that second (smoke) exhaust on a rocket engine for?
In this video of a Korea Aerospace Research Institute (KARI) rocket engine test, you can clearly see a second exhaust where thick smoke comes out.
Is this an essential part of the engine, or just an extra attribute required when testing? In both…
user10509
10
votes
3 answers
Why not use tap-off gas for repressurization for a simple rocket engine cycle?
In a tap-off cycle, combusted gases are extracted from the combustion chamber and routed to the turbines, which then drive fuel/oxidizer pumps.
In a pressure-feed cycle, fuel/oxidizer is fed into the combustion chamber by high tank pressures. A…
spookysys
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10
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Multiple engines vs one engine with multiple combustion chambers
What is the fundamental difference between a construction of n engines vs one engine with n combustion chambers?
For example, Energia rocket used four boosters, each with a 4-chamber RD-170 engine, and four separate single-chamber RD-0120 engines…
SF.
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How much propellant is "wasted" in the gas generator power cycle?
The gas generator power cycle is an open cycle, with pre-burner exhaust vented after driving the turbine instead of contributing to thrust as in more advanced power cycles.
What percentage of the propellant is usually used to feed the pre burner?…
user3596218
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Is it possible to keep fuel and oxidizer tanks pressurized during flight by heating up their contents using exhaust gases?
This could be done by leading tapped-off exhaust gases through heat-exchangers in the tanks (being careful that the exhaust gases don't freeze and block the pipe).
I'm imagining this as an alternative to carrying separate pressurization gases in…
spookysys
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4
votes
1 answer
In turbopump designs where no propellant is dumped overboard what causes efficiency loss in engines?
In some turbopump designs, propellant is burned and used to power the pumps; then it is dumped overboard. This causes a reduced specific impulse, because not all all the propellant is expelled through the nozzle in an efficient way.
However, some…
BWG
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2
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Layout of regenerative cooling tubing?
In F1, and space shuttle engines (I think), the regenerative cooling tubing goes through the inner wall of the nozzle. The russian engines (RD-180 and likes) seem to have smooth inner and outer surfaces for the nozzle. However, I think the outer…
user2277550
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How is gaseous fuel injected in Raptor engine's combustion chamber?
If liquid fuel and oxdizer is injected in a rocket combustion chamber, the mixture will be moving relatively slow before reaching the nozzle, preventing the flame front from escaping outside the engine.
But if the fuel and oxidizer come from gas…
ElEmparuMC
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Could a high specific impulse chemical rocket be built by using some of the fuel in a closed cycle to heat the exhaust?
There is a fundamental limit to the specific impulse of a chemical rocket because the propellant is also the fuel so you are limited by the fuels energy density. What if you burnt some fuel in a closed cycle, and then through the use of heat…
Lex
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