Computational study of Supercritical Forced Oscillations in a Mixed-Compression Air Inlet at Mach Number of 2

This study examines forced oscillations under supercritical conditions in a supersonic air inlet designed for a Mach number of 2. The preparation of inlet geometry, fluid flow simulations, and result postprocessing are performed using Ansys software and some in-house Fortran and Matlab numerical codes. Turbulence modeling was performed using the kω−SST turbulent model which has been approved in the past. The disturbances at the inlet’s exit are due to flow fluctuations in the combustion chamber. These are modeled by applying a sinusoidal excitation function in this study. The excitation function’s key parameters are amplitude and frequency. Despite the complex flow in the field, one of the main findings of this study is the observation of a frequency similar to the excitation frequency. Furthermore, the study investigates the effects of different excitation parameters on the upstream movement of fluctuations, and as the most important achievement the physical phenomena of supersonic flow are fully described.