楔形体底升角对入水多相界面演化作用研究

Study on Effect of Dead-Rise Angle on Evolution of Multiphase Interface in Wedge Water Entry Problems

跨介质入水是一个具有强非线性的多相流动问题,涉及到入水冲击、流动形成和空泡演化等多个方面。入水空泡的存在对物体的冲击载荷特性和运动特征有重要影响,同时入水空泡的发展受物体的几何构型及入水速度等多种因素影响。结合光滑粒子流体动力学(SPH)方法在处理大变形和运动界面问题上的优势,考虑空气在入水过程中的影响,建立了适用于跨介质流固耦合问题的多相流SPH模型。选取楔形体入水算例为研究对象,对数值模型进行了验证,模拟了多相流场下的空泡发展过程,并分析了结构几何形状对入水冲击的影响,结果表明楔形体底升角对空泡形态和闭合特性有重要影响。

Water entry is a multi-phase problem with strong nonlinear, involving impacting, flow formation and cavity evolution.The existence of water entry cavity has a significant impact on the impact load and motion characteristics. The development of water entry cavity is affected by many factors such as the geometric shape of objects, impact velocity, and so on. The characteristics of cavity evolution during water entry are studied using a multi-phase solver based on Smoothed Particle Hydrodynamics(SPH) method.A typical water entry case is selected as a benchmark to verify the numerical model, and the flow characteristics with respect to the generation, development and closure of cavity during the water entry process are analyzed. Then the water entry of wedges with different dead-rises are simulated. The results indicate that the cavity behaviors, including cavity shape evolution and pinch-off location, are significantly affected by body geometry.