Wall temperature effects on shock wave/turbulent boundary layer interaction via direct numerical simulation

Shockwave/turbulent boundary layer interaction on flat plate are investigated by using direct numerical simulation at different wall temperature of Tw/Tr=0.5,1.0,2.0 respectively. Responses of skin friction, velocity profile and root mean square velocity profile are examined. Analysis on velocity profiles indicate that streamwise velocity in the outer part of boundary layer experiences a reduction with wall temperature going up. Skin friction decreases while wall is heating mainly caused by a lower velocity gradient near the wall at a high temperature. A lower skin friction on high wall temperature results in a stronger separation. The comparison of root mean square velocity profile shows turbulent kinetic energy is augmented on a heating wall. The maximum value moves closer to the wall with wall temperature increasing. The scale of separation bubble is amplified with wall temperature increasing. Near-wall streaks become unstable and get an increment in spanwise distance. The process of near-wall strip vortices evolving to complicated 3-dimonsional structures is accelerated and amplified in a high wall temperature. Counter-rotating vortex in reattachment process is evaluated in the three cases. The scale of such vortex gets larger when wall temperature gets higher. The spanwise distance between counter-rotating vortices rises obviously and break down to smaller coherent structures quicker. •Skin friction goes down with wall temperature increasing.•Near-wall streaks stay more stable on a cooling wall due to weaker momentum exchange.•Separation gets stronger on a heating wall.•Maximum of turbulent kinetic energy moves closer to the wall with wall heating.•Evolvement of coherent structures is accelerated on a heating wall.