Experiment and numerical investigation of flow control on a supersonic inlet diffuser

Design of a two-dimensional supersonic inlet was developed. Numerical simulation and wind tunnel experiment were carried out to investigate the aerodynamic performance and variable geometric rules of the inlet. The result indicates that the variable geometry scheme adopted solves the contradiction between starting performance at low Mach number and aerodynamic performance at high Mach number. Inlet works normally and stably over a wide speed range. Compared with the diffuser without suction, the performance of the diffuser with suction is higher. Total pressure recovery coefficient sigma(e) improves by 2%-3% while outlet Mach number decreases by about 0.03 under different inflow Mach numbers. During the process of shock train moving upstream, the propagation gradually transforms from up and down mode to left and right mode. Flow separation caused by the shock train is mainly concentrated on the sidewall in the upstream of the diffuser. Sidewall suction case is more effective to eliminates the low-energy flow and stabilize the terminal shock wave. As backpressure increases, shock train changes from weak lambda-type to strong lambda-type and finally to X-type near the suction slots. (C) 2020 Elsevier Masson SAS. All rights reserved.