Questions tagged [scramjet]

A jet engine that uses ram pressure to compress incoming air, and where the airflow throughout the entire engine is at supersonic speeds.

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86 views

Rocket Thrust vs Air breathing jet engine why is a rocket better [duplicate]

What are design dynamics that give the rocket engine higher thrust than an air breathing jet engine of similar size in comparison to a turbo jet engine, turbo fan engine, high by pass turbo fan engine,...
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Does/Can combustion instabilities occur in SCRAM jet?

I was told that combustion occurs at Supersonic speeds in SCRAM jet. So acoustic disturbances/ pressure fluctuations can't travel into incoming jet stream. Does this avoids combustion instabilities in ...
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1answer
201 views

Could liquid alkali metal fuels be used for ramjet/scramjet propulsion?

In particular, I'm thinking about lithium, but sodium could be considered as well. Lithium has low molecular weight, very high propellant density, and low melting point. At sufficiently high ...
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2answers
261 views

Could hydrazine be used as a scramjet propellant?

Hydrazine is used a monopropellant in Satellite OMS rockets. But interestingly enough, it's highly exothermic decomposition into ammonia, nitrogen, and hydrogen provides heat for an endothermic ...
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3answers
204 views

What mechanism or design aspect prevents jet blast from escaping the front of a Ramjet or scram jet?

Enormous air pressures result in the thrust of a Scram jet or ramjet engine, more so the pressure required to drive the aircraft forward at supersonic and hypersonic speeds. Given that these engines ...
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1answer
543 views

What technical problems stopped scramjets from being used on hypersonic aircraft?

I have been researching hypersonic aircraft and scramjet engines after running a few calculations looking at ramjet/rocket hybrids for making single stage to orbit vehicles. After doing the analysis ...
2
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1answer
258 views

Is there a viable alternative to liquid hydrogen as a fuel for scramjets?

Given the difficulty and complexities of storing liquid hydrogen for commercial flight and the high velocity of air passing through a scramjet, do other types of fuel provide a feasible alternative ...
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0answers
70 views

What is the operating temperarature of a scram jet at its theoretical maximum speed?

What is the operating temperature of a scram jet at its theoretical maximum speed of Mach 24? For those with access to a simulator and do such simulators exist and are they possible? Given this ...
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0answers
541 views

What is the effect of Mach number on efficiency, thrust and specific fuel consumption of a ramjet engine?

My graphs show that overall efficiency and thrust first increase, reach a peak and then fall in the supersonic range (M=1-5) whereas SFC first and then increases rapidly near M 5. Why does this ...
6
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3answers
6k views

Are there any planes that have ramjet or scramjet engines?

Are there any planes that have ramjet or scramjet engines? If so, how did they reach the required mach speed for the engines to start functioning?