Receptivity of a supersonic boundary layer over a flat plate. Part 2. Receptivity to free-stream sound

摘要: In this paper, we continue to study the mechanisms of receptivity supersonic boundary layer free-stream disturbances by using both direct numerical simulation and linear stability theory. Specifically, a Mach 4.5 flow over flat plate fast acoustic waves is studied. The slow waves, entropy vorticity will be studied in future. oblique shock wave induced boundary-layer displacement plays an important role because disturbance first pass through before entering layer. A high-order shock-fitting scheme used simulations order account for effects interactions between wave. results show that flat-plate leads excitation Mack modes family stable modes, i.e. mode I, II, etc. It found forcing do not interact directly with unstable modes. Instead, I play process they Mack-mode waves. Through interactions, transfer energy from second incident angles, frequencies, wall temperature perturbation conditions on are very different those which properties these discrete conditions. maximum receptivities mode, II planar obtained when angles approximately equal 26 ◦ ,4 5 , 18 ,r espectively. beam leading edge one most efficient regions receptivity.