Underwater shock-free surface-structure interaction

A recently developed numerical method has been employed to evaluate the influence of free surface on shock loading in a cylindrical underwater explosion carried out near to both a free surface and a cylindrical rigid structure. In the usual simulation of underwater shock-structure interaction, the shock loading tends to accelerate/move the (rigid) structure only in the resultant force direction. The presence of a free surface and explosion bubble suggests the existence of a reverse loading and provides an additional torque (rotational moment) on the loaded structure. The numerical results also demonstrate the possible existence of a cavitation zone/region in the immediate vicinity of the free surface due to the near-surface underwater explosion.