An interface sharpening technique for the simulation of underwater explosions

In this study, a simple and effective interface sharpening technique is proposed to simulate underwater explosions. The five-equation model is used as the numerical model for underwater explosions. The multi-dimensional problem can be split into multiple one-dimensional problems using the Strang splitting. The MUSCL–Hancock Method (MHM) is employed to solve the governing equations in one-dimensional space, and the HLLC (Harten–Lax–van Leer contact) scheme is adopted to solve the Riemann problem approximately. The numerical results show that the five-equation model cannot accurately simulate underwater explosions due to the diffusion problem. To overcome this problem, a new interface sharpening model based on the five-equation model is obtained by adding the anti-diffusion source term to the volume-fraction transport equation. A fractional step method is employed to solve equations of the interface sharpening model in two separate steps. The model is validated by conducting numerical cases. On this basis, the one-dimensional and two-dimensional underwater explosion simulations are conducted. The numerical results indicate that the interface sharpening model based on the five-equation model can accurately simulate underwater explosions.