Archive for the ‘scramjet’ Category


Because I already got some objections about the fact that no normal person could possibly know what a SCRAMJET is, I put some pictures of 2 concepts of a SCRAMJET-based aircraft. Principally, such an engine does not have any moving parts like turbines, axes, etc. As simple as its geometry is, as complex is the flow-phenomena happening inside it. The air enters in the engine at a hypersonic velocity ( Mach > ¬†5, meaning at least five times more than the speed of sound, meaning more than 1500 m/s ) creating shock-waves whenever it encounters even the smallest geometry change (angles or obstacles). Because of these shock waves the flow is decelerated up to approximately Mach = 2 in the combustion chamber. There the fuel (in most of the cases hydrogen is preferred) is injected, mixed with the air, ignited and burned while is traveling further downstream. At the end of the combustion chamber the supersonic flow is expanded, therefore accelerated, producing thrust. And ta daaaaaa! You got yourself an engine! The principle is quite simple, is the details which are killing us: like the shock-waves which are reflecting at the wall, like the fuel-air mixing, like the types of injectors we prefer, like what materials we want to use to support such high heat loads… and all kind of crap.

So..with this, I hope I haven’t bored you. If you, however, want more of this supersonic stuff¬†just raise your hand and I will be coming to your desk to deal with it.

Signed: the mad scientist on duty


Here you see the difference between a conventional engine and a SCRAMJET. The X43 A concept is a very nice story told by proud NASA people. They actually managed to fly the thing some years ago.


The HVT-3X is an aircraft to be….

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