A ramjet, sometimes referred to as a stovepipe jet, or an athodyd,'s a form of jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets therefore require forward motion through the air to produce thrust. Ramjets require considerable forward speed to operate well, and as a class work most efficiently at speeds around Mach 3, and this type of jet can operate up to speeds of at least Mach 5. Ramjets can be particularly useful in applications requ… (More on Ramjet)