通气超空泡航行体后体纵摆运动的数值模拟

A numerical simulation of pitching motion of the ventilated supercaviting vehicle around its nose

利用Fluent 6.3对带圆盘空化器的高速水下航行体的通气超空泡流动进行了三维、非定常的数值模拟,通过在FLUENT软件中加入UDF自定义函数的方式求解非惯性系下的N-S方程,分析了通气超空泡航行体水下纵摆运动过程中的超空泡流流动特征和力学特性。结果表明,三维轴对称超空泡水下航行体的压力场具有如下特点:(1)泡内压力低于外界同样水深处水流压力,(2)泡内压力与泡外压力连续变化,(3)泡内压力分布不均匀,泡内气体在压力差驱动下形成沿周向的二次流动;该二次流动是形成超空泡尾部涡管状泄气结构的重要因素。文中将仿真计算结果与空泡水洞试验进行了对比,验证了数值计算的有效性。

In order to investigate the hydrodynamic and the flow characteristics of high-speed underwater vehicle pitching with a ventilated supercavity around its nose,some UDF（user defined functions） subroutines have been added into CFD software,Fluent 6.3.A three dimensional method was brought forward to calculate steady and unsteady ventilated supercavities based on the non-inertial system of coordinates.The simulated results indicated that the pressure field around an axisymmetic vehicle has following characters： 1.the static pressure value inside supercavity is lower than that outside one at the same water depth.2.the pressure is continuous crossing the cavity boundary.3.the pressure inside the whole cavity is not uniform.This pressure difference caused circumfluences inside the supercavity and led to a pair of aerofluxus vortex tube at the end of supercavity.Some comparisons with experimental results were given.The availability was verified.