Dynamic characteristics analysis of hammer shock in serpentine inlet

To analyze the dynamic characteristics of hammer shocks caused by engine surge, a serpentine inlet with a front fuselage is simulated under conditions of subsonic inflow and three flight angles based on the improved delayed detached eddy simulation method. An unsteady back pressure boundary condition in an aerodynamic interface plane is used to simulate the overpressure during engine surge. There is a certain angle between the normal line of the hammer shock and the centerline, which is approximately equal to the corresponding flight angle. The inlet wall pressures are above 2.3 times of the free-stream static pressure, and even local transient pressures reach more than 3 times. Complex flow field structures are generated behind the shock, which are affected by the centrifugal force and lateral pressure gradient. The velocities and intensities of the hammer shocks and the pressure distributions on the wall and the shapes of the flow field structures are greatly affected by the flight angle. In a large yaw angle, the hammer shock velocity is the fastest, and the internal airflow and load are the most severe. In particular, it is necessary to consider the influence of the ultra-high dynamic loads in the opposite direction at the two bends in a short period of time.