圆盘水面弹跳过程运动特性数值研究

本文基于CFD方法对圆盘撞水弹跳过程的运动特性进行了研究,对三种典型撞水运动状态进行了模拟,数值结果与文献中的试验结果吻合良好.基于计算结果,获得了圆盘可以成功弹跳的初始参数组合范围.圆盘弹跳过程中,前方会产生一股射流,其脱离圆盘的射出速度可以达到入水速度的两倍左右.随着圆盘自旋速度的增加,圆盘受到的流体动力逐渐增加,但速度衰减也随之逐渐增加.相对较小的初始倾角和入水角总是有利于圆盘撞水后的弹跳,但过小的初始倾角可能会不利于连续多次弹跳过程.对圆盘连续弹跳过程的数值模拟结果表明,圆盘运动路线并非一直向前,而是受自旋影响运动方向有一定程度的偏转,圆盘第一次撞水弹跳的高度和距离远大于后面几次的弹跳过程.

Numerical Study on Kinetic Characteristics of Disk Skipping over Water Surface

The kinetic characteristics of a disk skipping over the water surface was studied in this pa-per based on the CFD method. Three typical impact states were simulated and the results were in good agreement with experimental results. The domain of successful skips with different initial parameters was obtained from numerical simulations. In the skipping process, a water jet forms ahead of the disk and the velocity of the jet separating from the disk could be twice as fast as the velocity of disk move-ment. With the increase of the spinning velocity, the hydrodynamic response of the water to the disk in-creases while the velocity attenuation of the disk also increases. The initial state with a relative small incidence angle and a tilt angle is always propitious to a successful skip, but a too small tilt angle may not be conducive to multiple skipping process. The simulation results of a complete disk skipping pro-cess indicate that the disk movement orientation is not straight forward but has a deflection in one di-rection affected by the spin. The height and distance of the first skip are much larger than those of the rest skips.