Numerical Study Of Underwater Explosion Bubble Dynamics And Damage To An Adjacent Structure

Underwater explosion is a complex physical and chemical process with energy transforming. Its destructive force is the most threat to naval ship lives. Usually underwater explosion physical process is divided into two sequences: (1) Shock wave, (2) Bubble oscillation. In the past, People payed more attention to shock wave, but the experiment and analyse in lastest decades show that bubble oscillation can also cause serious damage to ships or other structures. Underwater explosion bubble movement and interplay between bubble and structure are becoming a focus in international researches.This paper analyzes explosion bubble dynamics and the response of structure under bubble loading by numerical methods. The boundary integral method is used to solve Laplace equation based on potential-flow theory. Coupled with time integral, we establish three-dimensional model of an underwater explosion bubble near a structure. Our main job is as follows:1. Formulate the equations that control bubble dynamic movements, realize discretizing all surfaces into a serial of cells through boundery integral method and finally simulation of bubble dynamic movement. Solve the numerical problems such as bubble large deformation and toroidal bubble modeling.2. Comparisons between numerical and experiment results indicate that they are in good agreement which conform our model accurate and stable. Numerical studies are carried out analyzing explosion bubble movement rules, summarizing jet forming.3. Simulate in detail the explosion bubble near an ellipsoid structure and a floating ship, analyze dynamic behavior every progress, obtaining the fluid pressure around bubble and loadings on structure every calculated step.4. Considering floating ship as a girder with varisized section, structure responses are calculated under loading of explosion bubble by a simplified coupled method.These studies are to be important references in the engineering field of underwater explosion bubble dynamics and destruction mechanism of structure in water. Thanks for National Natural Science Foundation project (code: 50579004).