Direct Numerical Simulation of Supersonic Flows over Two Tandem Cavities

Supersonic turbulent flows over two tandem cavities are investigated by direct numerical simulation. For the purpose of comparison, a single cavity case is also included. The flows at Mach number 1.5 and 2.5 are calculated. The interactions between the two cavities are carefully studied. Results show that the cavity flows are basically dominated by the shear-layer oscillations. The upstream cavity can strengthen the shear-layer over the downstream cavity and reduce its sound pressure level on the walls. Contrarily, the impact of the downstream cavity on its upstream counterpart is weak. The sound waves generated by the cavities are directional. Their directions of propagation are affected by the Mach number. © 2020, Science Press. All right reserved.