Receptivity of a supersonic boundary layer to solid particulates

摘要: Laminar–turbulent transition in the boundary layer at supersonic speeds can be initiated by small solid particles present free stream. Particulates interacting with boundary-layer flow generate unstable wavepackets related to Tollmien–Schlichting (TS) waves. The latter grow downstream and ultimately break down turbulent spots. This scenario of TS-dominated is modelled using Mack amplitude method. A theoretical model describing receptivity mechanism developed predict initial spectrum TS With these conditions growth instability calculated linear stability theory. onset associated point where disturbance reaches a threshold value. As an example, calculations are carried out for 14° half-angle sharp wedge flying standard atmosphere altitude 20 km, Mach number 4 zero angle attack. It shown that spherical radius from density cause corresponding amplification factor , which empirical range flight data. indicates atmospheric particulates may major source on aerodynamically smooth surfaces speeds. provides foundation further treatments different cases dusty environments. also used predictions particle-induced subsonic hypersonic