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 T-w/T-r = 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.

Automated summary

The interaction between shockwave and turbulent boundary layer on a flat plate was investigated through direct numerical simulation at different wall temperatures. It was found that as the wall temperature increases, the skin friction decreases, resulting in stronger separation and increased turbulent kinetic energy on the heating wall. The study also observed an acceleration and amplification of the process of near-wall strip vortices evolving into complicated 3-dimensional structures at high wall temperatures.