带尾翼水下自然超空泡射弹数值模拟研究

基于Navier-Stokes方程,考虑气液间相变,采用大涡模拟湍流模型,PISO算法及VOF方法,利用自行开发的程序对绕三维带尾翼水下自然超空泡射弹的非定常空泡流动进行了数值模拟研究.通过计算结果得到超空泡从射弹头部初生至完全包裹弹身的形成过程.在此基础上,计算不同攻角条件下的超空泡形态,并给出射弹表面空泡厚度分布曲线,分析不同攻角对超空泡形态特性的影响规律,以及在零攻角条件下,分析尾翼对空泡形态的影响.另外计算不同空化数条件下的超空泡无量纲长度和厚度,将计算结果与实验数据进行对比,两者吻合较好.研究结果为进一步研究水下高速射弹的水动力特性和弹道特性问题提供理论基础.

Numerical investigation of underwater natural supercavitating projectiles operating with the empennages

Based on the Navier-Stokes equations,adopting the LES turbulence model,algorithm of PISO and VOF method,the numerical simulation of three-dimension unsteady cavitating flow around supercavitating wing-projectile adopting the self-developed program has been implemented in this paper,through the consideration of mass transfer between gas and liquid.The process that the supercavity configuration produces from warhead of projectile until enwraps the whole body is achieved.Based on it,the cavity configuration is calculated at different attack angles,and the distributed curves of cavity thickness on the surface of projectile are also given.The analysis that different attack angles influence the configuration characteristic of cavity has been made,and also the effect of empennages and cavity configuration in conditions of zero attack angle.Furthermore,the dimensionless length and thickness of supercavity at different cavitation numbers have been calculated.The comparison of calculation result with experiment result has been made.It is indicated that numerical result can preferably agree with the experimental result.This research offers academic reference for the study of hydrodynamics and ballistic performance of underwater high-speed projectiles.