Numerical study of the effect of exit configurations on supersonic inlet buzz

Numerical simulations of flows around Nagashima et al.'s supersonic inlet with three exit configurations are performed to determine the effects of exit configurations on inlet buzz. Two exits are axisymmetric configurations with different locations, and the other is a 3-D configuration exit with several holes. The supersonic inlet used in the simulations is an external compression type, and axisymmetric except the exit. Three-dimensional simulations are carried out using a Reynolds-averaged Navier-Stokes (RANS) solver with the Spalart-Almaras turbulence model. Results with two axisymmetric exit configurations indicate that the amplitude of the pressure oscillation and the dominant frequency are larger than those of the experimental data. On the other hand, the result with the 3-D configuration exit shows that both the pressure history and the dominant frequency are good agreement with experimental data.