Investigation On Cavitation Of Underwater Explosion Shockwave Near Complex Boundaries With Coupled CEL Method

In the field of ship and marine engineering,underwater explosion has always been a hot topic of scholars to improve the ship’s anti-blast capability is the focus of national navies.Submarine explosions often make the ship plastic deformation and even break the case,so the study of underwater explosions not only help to understand the mechanism of underwater explosion damage on the ship,but also contribute to the ship’s impact resistance design,Help to improve the vitality of naval vessels.The forms of underwater explosion damage to the ship are mainly divided into the damage of the ship by the shock wave,the damage of the ship by the bubble pulsating load and the damage of the ship by the cavitation effect.There has been a great deal of research on shock wave and bubble pulsation all along,but there are few researches on underwater cavitation cavitation.This paper mainly studies the cavitation phenomenon caused by underwater explosion.Reflection occurs when the shock wave reaches the fluid-solid interaction interface.The superposition of the reflected wave and the incident wave may cause a negative pressure zone near the interface.Cavitation occurs when the pressure in the water reaches the cavitation pressure of water.Cavitation Will be secondary structure of the nearby load effect and thus damage the structure.First of all,this paper starts with the basic phenomena of fluid-solid coupling in underwater explosion,and uses acoustic-structure coupling method to simulate one-dimensional cavitation phenomenon in classical Bleich&Sandler one-dimensional plate model,and calculates the change of cavitation area and flat plate velocity in one-dimensional plate model.The law,which compares the calculated results with the analytical solutions,verifies the accuracy of the acoustic-structure coupled method for calculating underwater explosion and cavitation problems.Secondly,based on the axisymmetric model,the infinite wide water area,the cylindrical water area with rigid wall,the underwater explosion process and the cavitation phenomenon in a flat plate water area are simulated.Under different boundary conditions,the shock wave in the free surface Near and in the vicinity of the rigid wall,and investigates the pressure-time characteristics at different locations in the cavitation zone.Based on the three-dimensional finite element model,the underwater explosion process and cavitation in a wavy wall with a wavy wall and a wavy surface were simulated.The influence of boundary conditions on the cavitation characteristics in a three-dimensional water area was summarized.Pressure Characteristics in Secondary Cavitation in Different Boundary Waters and Secondary Loading.In this paper,based on the acoustic-mechanical coupling method,the underwater stiffened plate structure and the cabin structure in the typical structure of a ship are numerically simulated.The characteristics of the stiffened plate and the cavitation area near the cabin structure under shock wave are studied.Considering the cavitation effect and the dynamic response of the structure without considering the cavitation effect,the phenomenon of secondary loading of the cavitation phenomenon is discussed,which aims to provide a reference for the study of underwater explosion and ship impact.