The effects of computing grid and artificial viscosity coefficient on underwater explosion numerical simulation

The mesh size and artificial viscosity coefficient have great effects on the calculation accuracy of underwater explosion numerical simulation. The reasonable mesh size and artificial viscosity coefficient are very important to improve the accuracy and reduce the amount of calculation. The underwater explosion test of TNT is carried out. The maximum shock wave pressure and the bubble pulsation period are calculated by using the empirical formulae based on underwater explosion similarity law, and the accuracy of empirical formulae is verified by the experimental results. The underwater explosion numerical models of cylindrical and spherical charges are established, the underwater explosion processes are calculated in different mesh sizes and artificial viscosity coefficient. The effects of mesh size and artificial viscosity coefficient on the maximum shock wave pressure and bubble pulsation period are analyzed by comparing the numerical results with the empirical results. The results show that the maximum shock wave pressure is an exponential function of the mesh size and the artificial viscosity coefficient, and the higher accuracy of underwater explosion numerical simulation can be achieved when the mesh density is more than 400 times of the artificial viscosity coefficient.