Numerical investigation on the hydrodynamic characteristics of a cylinder of different head construction out of launch tube

The effects of the head-form on the hydrodynamic characteristics during the launching of underwater vehicles out of a vertical tube were numerically solved by combining the mixture model, Singhal cavitation model, and standard turbulence model into the Reynolds-averaged Navier-Stokes (RANS) equations under the dynamic mesh system, and the solutions of the interaction of the dynamic boundary conditions of the cylinder and environmental fluid were obtained. The axial symmetric gravity flow field and hydrodynamic characteristics of the underwater cylinder were derived by using numerical simulation. Simulation and analysis results show that different head construction affects the trajectory of the underwater cylinder and hydrodynamic load. The volatility reason of differential pressure coefficients and viscous force coefficients as well as toll force coefficients were derived by analyzing simulation results. Water trajectory and hydrodynamic force of the #3 model is relatively stable in the process of launching from the tube, which may give it various engineering applications.