NUMERICAL SIMULATION OF CHAIN-REACTION IMPLOSIONS AND ANALYSIS OF DIFFERENT IMPLOSION BEGINNING POSITIONS

Hollow ceramic pressure hulls in the deep-sea underwater vehicles have potential risk of destructive chain-reaction implosions. A numerical simulation method for the chain-reaction implosions of multi-ceramic pressure hulls is developed. The underwater implosion in the ultra-high pressure is solved by the compressible multiphase flow theory. This method has been verified by the comparison with implosion experiments. The structure finite element method (FEM) is used to solve the response of ceramic pressure hull under implosion flow field loads and is combined with the failure criterion of ceramic materials as the judgment basis for inducing implosion. It is found that the pressure drop caused by the expansion wave generated by the implosion of the ceramic pressure hull triggers the implosion of the adjacent pressure hull. The implosion shock waves overlap each other, and generate shock wave pressure peaks larger than the implosion of a single pressure hull. Finally, three ceramic pressure hulls are arranged in a straight line, and the influence of different beginning positions of implosion on the flow field is also compared and analyzed.