摘要
为了了解涡环泄气方式下通气空化的非定常流动特性,采用实验和数值计算的方法研究了绕锥头回转体通气空化流场。数值计算中,为了精确捕捉由于分离流动而产生的旋涡结构采用了基于空间尺度修正的滤波器模型(FBM).实验中,采用高速录像技术观察了对应工况下绕锥头回转体通气空化的空泡形态。研究结果表明:数值计算与实验结果取得较好的一致;通气空化的非定常流动现象为空泡尾流区云雾状空泡团的断裂脱落过程;空泡闭合位置的高压与空泡区域的低压形成较大逆压梯度,使空泡区域出现流动分离,进而在空泡区域产生复杂的旋涡结构,此旋涡结构与主流相互作用引起了空泡断裂,从而产生了脱落空穴涡。
To understand the unsteady characteristics of ventilated cavitation in the form of gas-leakage by toroidal vortex,the ventilated cavitating flows around axisymmetric body are researched by the experimental and numerical methods. A filter-based turbulence model is used in numerical simulation in order to accurately capture the vortex separation. In experiment, the high-speed video camera is used to observe the flow structure. The results show that the numerical results are consistent with the experimental resuits. The unsteady ventilated cavitating flow is the shedding process of cloud bubble in the rear of venti- lated cavity. Flow separation in the region of ventilated cavity is caused by adverse pressure gradient, resuiting in a complex vortex structure. An interaction between vortex structure and the main flow leads to the cloud bubble shedding in the rear of ventilated cavity.
出处
《兵工学报》
EI
CAS
CSCD
北大核心
2014年第5期711-718,共8页
Acta Armamentarii
基金
国家自然科学基金重点项目(51239005)
关键词
流体力学
通气空化
逆压梯度
流动分离
空泡脱落
fluid mechanics
ventilated cavity
adverse pressure gradient
flow separation
bubble shedding
