“…Also, flow conditions will make change when the planes takeoff, land or change the flight condition, which can lead to the corresponding change inside of the inlet flow, further affect the performance of the engine parts and even the whole machine. The study of flow characteristic of inlet started early abroad; however, the in-depth study of S-shaped inlet begins with a jet plane, and then has been applied on the cruise missile [4][5][6][7][8][9][10][11][12] . Plas [13] systematically studied the boundary layer suction for promoting the performance of the system, the results show that the boundary layer suction can reduce fuel consumption by a few percentage points, and the distortion along the piping is the main reason for the overall performance.…”