Abstract:
The state equation for detonation products is one of the fundamental equations in computational explosion mechanics, and changes in the values of its parameters directly affect the results of numerical analysis. This study focused on the influence of the parameters of the JWL(Jones-Wilkins-Lee) state equation for TNT explosives on the numerical simulation of underwater explosion shock waves. Based on the LS-DYNA finite element program, a refined one-dimensional numerical model of underwater explosion was constructed by comparing with empirical formulas. An in-depth analysis was conducted on the variation laws of key processes, such as the pressure attenuation of explosion shock waves and energy release under different values of each parameter in the JWL state equation for detonation products. The results show that the parameters of the JWL state equation have significant impacts on parameters such as the peak pressure, specific impulse, and specific shock wave energy of underwater explosion shock waves, and the impact varies at different distances from the explosion center. In terms of peak pressure, in the near field range, the influence of R1 is much greater than that of other parameters, while in the middle and far field ranges, E0 has the greatest influence. Moreover, a higher peak pressure indicates a faster attenuation. In terms of specific impulse, changes in E0 have the greatest influence, and when E0 is changed, the calculated value of specific impulse has a linear relationship with the parameter value. Similarly, E0 has the greatest influence on specific shock wave energy. The research results can provide a reference basis for the reasonable selection of JWL equation parameters in the numerical simulation of underwater explosions.