Abstract: In order to determine the time of the dry bay ignition and the leak speed of fuel after an aircraft is impacted by a high-speed projectile, it is necessary to analyze the cavity formation and collapse induced by high-speed impact and penetration of a rigid projectile into the fuel tank, and determine the cavity collapse completion time and pressure. For simulating the process of the cavity formation and collapse induced by high-speed projectile prenetrating into the fuel tank, an analytical model and a numerical model are founded in this paper. It analyzes the energy transfer for cavity formation and the energy dissipated by the velocity-dependent drag on the projectile, and calculates pressure in the cavity, cavity collapse completion time and location. The results show that the pressure in the cavity and the cavity collapse completion time are almost constant and independent of the impact velocity for a given projectile, and that the collapse initial location is a weak function of the impact velocity.

Key words: fuel tank, dry bay, impact, cavity, projectile