航行器垂直入水空泡特性与流体动力研究

Research on Cavitation and Hydrodynamic of Vertical Water-Entry for Supercavitating Vehicles

研究超空泡航行器垂直入水空泡形态与流体动力特性,针对空泡出现流体动力特性改变,为了确定入水参数,根据标准k-ε模型,采用三维动网格技术,对超空泡航行器入水过程重力场下非定常空泡特性以及流体动力参数进行了数值仿真。得出结果,攻角越大,空泡形态不对称性越明显,迎流面空泡越短越薄,背流面空泡越长越厚,迎流面与背流面的空泡闭合时差越大,且流体动力系数越大。证明对同一入水深度时,从曲线上分析,阻力系数的斜率基本一致,升力系数与俯仰力矩系数的斜率随攻角的增大而增大。研究结果可为入水弹道的研究提供了流体动力参数。

Study on caviting shape and hydrodynamic on vertical water-entry of supercavitating vehicles.Based on standard k-ε model,the unsteady cavity character in a longitudinal gravity force field was numerically simulated by using 3D dynamic mesh technique during the supercavitating vehicle vertical enter water.Result shows that the angle of attack is larger,the asymmetry of the cavity is more obvious,the cavity of the confronted stream surface is shorter and thinner,the cavity of the opposing stream surface is longer and thicker,and the time difference of the closed cavity of the confronted and the opposing stream surface is longer.The angle of attack is larger,the hydrodynamic coefficient is larger;at the same water-entry depth,the slop of the drag coefficient curve is approximate equivalent at different angle of attack,and the slop of the lift coefficient curve and the pitching moment coefficient curve is larger with a larger angle of attack.The result can be used for research on water-entry trajectory.