The Coupling Effects Between the Underwater High-Pressure Bubble and the Marine Structure

Abstract

When underwater explosion breaks out, usually the bubble with a radius of meters is generated. The bubble’s oscillation may cause the damage of the floating structure thereabout. In the present paper, a 3-D Boundary Element Method (BEM) model based on the potential theory is implemented to simulate the strong non-linear interaction process. The focusing problem is to track the movement of the contact line between the structure and the free surface with some degree of robustness. Although the negative mirror image model could take the free surface’s effect into consideration without catching the contact line, its assumption that the free surface be motionless wasn’t tally with the real situation to some extent. Non-linear free surface effect is simulated in this paper. By splitting the nodes, both the Direchlet and the Neumann boundary conditions will be satisfied of the nodes on the contact line. Therefore, the moving boundaries’ deformation can consistent with the actual situation well. In this paper, the authors firstly introduce a 3-D BEM model for bubble dynamics, and present a way to deal with the strongly integral for the open boundary. Then the accuracy of the model is examined in comparison with the negative mirror image model. By using the numerical model, bubble dynamics near a marine structure with varying increment’s position and weight are studied respectively. We find out that the depth and the weight of charge will affect the bubble’s shape. This paper has its implication to offer ideas on multiphase fluid interaction and the damage mechanism induced by high-pressure bubble on floating structures.