Numerical research of water jet characteristics in underwater explosion based on compressible multicomponent flows

Abstract

Owing to the high-speed motion and high-pressure load characteristics of water jet, explosion bubble plays an important influence on the surrounding structures in underwater explosion (UNDEX). Based on interface compression and density correction treatment, an important compressible multicomponent flow model is proposed and its discrete method is briefly introduced in the study. This method shows a great potential in multicomponent flow, especially in the research of water jet characteristics caused by bubble collapse in underwater explosion. The bubble dynamic behavior caused by a weighted of 0.2 kg charge at a depth of 50 m is researched under the condition of different distance to diameter ratio near a rigid wall. It can be observed that when the bubble shrinks to the minimum volume, the collapsed pressure on the center of the wall (coordinate origin) does not reach the maximum, excluding γ = 0.24. Owing to the strong nonlinearity of the water jet, the characteristics of the pressure load on the wall are very complex. For the example in the study, the maximum water jet velocity under different γ conditions is between 140 and 280 m/s, and the maximum pressure of the bubble collapse on the wall is between 13.8 and 48.0 MPa. Under such a high-speed impact, a local high-pressure zone is formed near the wall, indicating that the impact damage caused by the water jet to nearby structures cannot be ignored in the underwater explosion.