超空泡航行器升沉运动流体动力特性研究

Research on hydrodynamic characteristic of super-cavitating vehicle in heave state

基于Rayleigh-Plesset方程的单一介质可变密度Mixture模型,采用动坐标系法完成了对带空泡航行器作升沉运动时空化流场的数值模拟,并分析了该状态下航行器流体动力特性变化规律,对升沉运动频率和幅值对航行器流体动力系数的影响以及升沉运动对航行器自主运动弹道的影响进行了对比研究。研究结果表明,升沉运动过程中,航行器流体动力系数出现周期性变化,增加升沉运动频率和幅值不仅将导致航行阻力和升力增大,同时会造成阻力系数和升力系数幅值波动加剧;升沉运动使航行器速度及角速度出现周期性震荡。本文结论为研究超空泡航行器动力学建模、附加质量计算及弹道设计奠定了基础。

Based on the Rayleigh-Plesset homogeneous hypothesis and the compressible Mixture multi phase model,numerical simulation of cavitation flow in the simple harmonic heave state of super-cavitat ing vehicle enveloped with cavity was performed in moving coordinate system. The law of changes of the vehicle＇s hydrodynamic characteristic was analysed. Also,a comparative study of influence of heave fre- quency and amplitude on the vehicle＇s hydrodynamic force coefficients was carried out. In heave state, the trajectory of vehicle＇s autonomic movement was simulated. Results have showed that in the simple harmonic heave state,the vehicl＆s hydrodynamic force coefficients change periodically. The increment of heave frequency and amplitude will cause drag force and lift force to increase, and intensify the amplitude fluctuation of drag coefficient and lift coefficient. The velocity and angle velocity are in periodic oscilla tion with the vehicle＇s heave. The conclusion of this paper can afford theory basis for the further study on dynamic modeling,added mass caculation and trajectory design and of super-cavitating vehicle.