Abstract:
The experiments of shock wave/transitional boundary layer interaction were performed in FD-20 wind tunnel to study the interactions between shock wave and transitional boundary layer. The experimental model was compression corner. The Mach number is 8, and the Reynolds number 0.5×10
7~2×10
7/m. Film resistance thermometers and pressure sensors were used in the experiments to measure the distributions of the heat flux and the pressure. According to the state of boundary layer in the upstream and downstream of the separation region, the experiment was divided into laminar/turbulence interference part and transition/turbulence interference part. The distributions of parameters and unsteady characteristics of heat flux fluctuations were compared in separation region where transition occurred. The experimental results show that the characteristics of the distributions of transitional interaction are different from those of the turbulence interaction and the laminar interaction. Cross-bispectrum analysis shows that the transitional fluctuations and the separation bubble fluctuations appear and grow simultaneously with the boundary layer transition occurring in separation region. The transitional fluctuations may interact with the separation bubble fluctuations nonlinearly, when the amplitudes of the both fluctuations are large enough. The fluctuation structures with new frequency characteristics are induced, leading to remarkable increment of the amplitudes of the fluctuations.