Simulation of Laser-induced Asymmetric Bubble With Lattice Boltzmann Method

摘要

In this paper,the Lattice Boltzmann Method is applied to set up the numerical model of cavitations.The surface of the part is introduced into the symmetric bubble model to form the more realistic model called asymmetric bubble.With the help of simulation,no pulsation is detected but it is noticed that the pressure is no longer present uniform distribution for the four virtual surfaces symmetrically set around the bubble.The pressure close to the part's surface is slightly higher and the velocity gradient is larger than those further away from the solid surface.And the distortion along the flow line is discovered at the end of the solid surface.The asymmetric bubble collapses in a complicated way thanks to the various velocities in different point of the bubble wall.What is more,a micro jet with radius of 10μm is generated which leads to the sharp reduction of momentum of the wall and the increase of the pressure near the bubble wall.According to the simulation,the impact on the work piece peaks at 1.6GPa.