无后体空化器双涡管泄气模式通气超空泡内部流动结构研究

Study on Flow Structure in Supercavity Ventilated by Double Vortex Tube in Backless Cavitation Device

该文基于数值仿真方法对由圆盘空化器产生的通气超空泡流动特性进行了研究。数值模拟考虑通气压缩性和重力效应,采用VOF多相流模型和SST湍流模型,建立了通气超空泡流动的数值模拟方法。分析了超空泡内部压力和速度的三维分布特性,研究了不同通气和来流参数对超空泡内部流动结构的影响。结果表明:沿来流方向,超空泡内部存在微小的压力增长;整体上,超空泡内部气体呈现明显的由外部水体剪切驱动的旋涡运动,空泡内正向流量系数CQ+的分布,尤其在空泡前半段具有确定的变化规律,几乎不随通气系数CQ和Fr数等无量纲参数而变化。

Based on the numerical simulation method,the flow characteristics of a ventilated supercavity generated by a disk cavitation device are studied.A numerical simulation method of ventilated supercavity flow is established by using VOF multiphase flow model and SST turbulence model,considering the ventilation compressibility and gravity effect.The three-dimensional distribution characteristics of pressure and velocity in supercavity are analyzed,and the effects of different aeration and inflow parameters on the flow structure in supercavity are studied.The results show that along the direction of incoming flow,there is a small pressure increase inside the supercavitation.On the whole,the gas inside the supercavitation presents obvious vortex motion driven by the shear of the external water.The distribution of the forward flow coefficient inside the cavitation,especially in the first half of the cavitation,has a definite change law,and almost does not change with the non-dimensional parameters such as the ventilation coefficient number.