Hypervelocity High Altitude and Low Dynamic Pressure Flexible Cover Correlation Between Wind Tunnel and Flight Interference Forces

The flexible cover is wrapped on the aircraft surface, and plays a protective role in the mid-flight. Due to the combined action of aerodynamics and aerothermodynamics during the reentry process, it pulls away from the aircraft surface and falls off, and the additional interference force/moment generated during the falling-off process affects the reentry attitude of the aircraft, causing inertial landing point deviation. The ground wind tunnel was used to simulate the hyperso-nic, high altitude and low dynamic pressure environment, to assess the separation process of the connecting rope of the flexible cover under the aerodynamic force under different reentry dynamic pressure conditions. The interference force/moment generated by the falling-off process on the aircraft was also examined. According to the dynamic similarity criterion, the falling-off process of the cover model under the ground test condition was deduced to the flight condition, and a rigid body dynamics simulation model was established to calculate the landing point. Compared with the theoretical landing point of the non-interference model, the probabilistic method was used to analyze the aircraft landing point deviation caused by the flexible cover falling off, so as to provide support for the optimal design of the flexible connection form.