Numerical study on dynamics of an underwater explosion bubble based on compressible homogeneous mixture model

•Dynamics of an underwater explosion bubble are numerically investigated.•The numerical method is based on a compressible homogeneous mixture model.•Good agreement is obtained between numerical and experimental results.•Details of the pressure pulse, water jet impact, and velocity field are discussed.•Effects of the buoyancy parameter on the bubble dynamics are carefully analyzed. A compressible homogeneous mixture model was adopted to numerically investigate the dynamics of an underwater explosion bubble. The bubble-water interfaces were captured by solving an interface advection equation using a compressive high-resolution interface capturing method. The numerical model was validated by comparison with experimental results for a free-field underwater explosion. The results exhibited good agreement overall. Complex phenomena of dynamic bubble motion, including the bubble expansion, contraction, collapse, jet, and rebound, were accurately predicted. Under the effects of buoyancy on the dynamic motions, the upward migration process of the bubble was determined and analyzed in detail. Furthermore, the pressure pulse and jet velocity fields at typical moments were examined. Additionally, the effects of the buoyancy parameter on the bubble dynamics were carefully investigated. It was found that the upward migration behavior was stronger and the non-dimensional maximum jet velocity decreases for a larger buoyancy parameter.