If the mach number is >> 1, the flow speed is much higher than the speed of sound - and the speed is hypersonic. Example - Calculating an Aircraft Mach Number An aircraft flies at speed 500 mph at an altitude of 35000 ft. The surrounding temperature is -60 oF. The speed of sound ...
These vehicles are driven by scramjet mode of operation at about 20–30 km altitude [1] where the ambient pressures and temperatures are low. To initiate combustion process under such conditions, it is necessary to compress the air to a required level [2]. Thus, ram compression is an ...