中文摘要：

针对圆柱体出筒过程头型对流体动力特性的影响，采用多相流Mixture模型、Singhal空化模型和标准的k-ε湍流模型的方法，并结合动网格技术，求解混合介质RANS方程，实现了圆柱体运动的动边界与流场的流体-固体耦合求解．以此为基础，对有重力影响下的3种头型的圆柱体出筒过程和流体动力特性进行了数值模拟，分析了头型对圆柱体出筒过程中水弹道及其流体动力特性的影响，以及圆柱体压差系数、粘性系数和总力系数变化规律及波动原因．得到模型Ⅲ出筒过程中流体动力变化较小和水弹道比较稳定的结论，为工程实际应用提供有意义的理论指导．

英文摘要：

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 k-ε 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 are relatively stable in the process of launching from the tube, which may give it various engineering applications.