用E-L方法计算圆平头物体垂直入水空泡的面闭合和深闭合

本文根据非线性自由面理论,用E-L方法计算了圆平头物体垂直入水空泡发生、发展、面闭合、拉离和深闭合等一系列连续变化过程。空泡中气体流动分为三个阶段加以处理。采用Riabouchinsky映象板模型,初步解决了高F_r数下数值模拟空泡深闭合的困难。计算结果表明,对于给定的物体头型,F_r数、空气出度数、物体质量数是影响入水空泡发展过程的主要因素。

NUMERICAL SIMULATION OF CAVITY SURFACE CLOSURE AND DEEP CLOSURE DURING VERTICAL WATER ENTRY OF DISK-HEAD BODIES WITH E-L METHOD

In the present paper, on the basis of nonlinear free surface theory, the various stages, such as open cavity, surface closure, pullaway and deep closure, of the cavity development after vertical water entry of disk-head bodies are simulated numerically by means of the E-L method. The air flow in the cavity is treated in three steps. By using the Riabouchinsky Imaging Model the author has solved the problem of simulating the process of cavity deep closure when the Fr number is high. Computational results show that the Fr number, the air-density number and the body-mass number are the primary factors of affecting the cavity development during water entry of a given body.