The starting performances of two typical supersonic sidewall-compression inlets were investigated from Mach number 1.5 to 5.0 by means of numerical simulation.The influence of height on performance was studied.The investigation shows that the flow features of inlets with different heights differ a lot during the starting process.For a proper height

the inlet performance prior to startup is improved significantly

oscillations of performance parameters become weaker

and the self-starting Mach number is smaller(a minimum value exists).In such case

the inlet with this height has a better starting performance

and can operate well when the incoming Mach number is less than self-starting Mach number.