Study On The Effect Of Bubble On The Flow Field In Underwater Explosion

The underwater explosion is divided into two stages,as the first stage,the shock wave phase has been formed in a very mature theory system,its impact on the structure in the water also has a lot of reliable analytical methods.As the second stage.compared to the shock wave phase,the bubble pulsation stage,its theory is not so mature.At the same time,bubble pulsation phase will not only do a damage to the ship’s local part,which caused serious damage,while because of the pulse frequency close to the ship structure natural frequency,it will cause the structure resonance and whipping response,thus causing damage which can not be ignored on the overall ship.Literature on the research of bubble pulsation pressure on the hull structure influence,the bubble pulsation pressure simulation usually adopts Vernon dimensionless equation.The bubble simulationis on the assumption that the surrounding fluid is inviscid,irrotational and incompressible,and the bubbles from the beginning to the end to keep the ball shaped.This research is using the MATLAB programming language to Vernon non dimensional equation to calculate the bubble radius changes with time.The bubble trajectories in the water,bubble induced flow velocity,acceleration and pressure on the size of the changes.At the same time,the kinetic energy of bubbles is discussed without considering the effect of bubble migration or free surface effect.With the change of time,the fluid acceleration vector field and the pressure contour can be more intuitive to understand the fluctuation of the bubbleand the change of energy in the flow field.Without considering the transfer effect,the kinetic energy of the flow field is bigger,and the kinetic energy of the flow field is smalerl when the free surface effect is not considered.Simply summing up with the increasing of distance,the flow field of kinetic energy change law.