Influence of vibration excitation on the zone of laminar–turbulent transition on a plate

Abstract

Abstract Influence of thermal nonequilibrium on the laminar–turbulent transition is studied on the basis of the eN -method for two widespread flow regimes of a supersonic boundary layer at Mach number M = 4.5. The set of actual frequencies of spatial disturbances was determined from the neutral stability curves for temporal disturbances. The families of N-factor curves were calculated for selected frequencies. The transition Reynolds number was determined for a given transition factor NT = 8 from the envelopes of the families of N-factor curves. Calculations show that for the level of the vibrational excitation below the dissociation limit and for NT = 8 the transition zone shifts downstream by 12÷14 % compared to a perfect gas.