Transition prediction of the supersonic boundary layer on a cone under the consideration of receptivity to slow acoustic waves

Transition prediction of the supersonic boundary layer on a cone with small angle of attack and Mach number 3.5 is investigated under the consideration of receptivity to slow acoustic waves, as the acoustic waves are the main environmental disturbances in a conventional, i.e. non-quiet, wind tunnel. It is shown that the e-N method can still yield fairly satisfactory results in comparison with those obtained in wind tunnel experiments, provided that the boundary layer receptivity to slow acoustic waves is properly taken into account, including the dependence of the amplitude of disturbances on the frequency and stream-wise location. Neither the conventional e-N method nor the improved e-N method can yield correct result of transition prediction, because the receptivity mechanisms considered there are not in accord with the real situation in the wind tunnel.