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为研究高速水流中旋涡空化的形成机理 ,用高速摄影和录像的方法观察了发生在中空射流阀内部流场的空化现象 ,采用数值模拟的方法计算了阀内部非定常粘性流场。发现流场中空化的产生与流动分离以及所伴随的剪切层区域的非定常旋涡运动有关。旋涡空化水流中有两种空穴 ,即空化泡与空化旋涡。在剪切层非定常旋涡从流动分离点产生的过程中 ,旋涡形成区域的压力进一步降低 ,在空化条件下产生大量的空泡 ,部分空泡被旋涡所包容 ,从而形成空化旋涡
In order to study the formation mechanism of vortex cavitation in high-speed water flow, the cavitation occurred in the internal flow field of hollow jet valve was observed by high-speed photography and video recording. The unsteady viscous flow field inside the valve was calculated by numerical simulation. It is found that the cavitation in the flow field is related to the flow separation and the unsteady vortex motion in the region of the shear layer. There are two types of voids in the vortex cavitation flow: cavitation bubble and cavitation vortex. During the shear layer unsteady vortex generated from the flow separation point, the pressure in the vortex forming region is further reduced, a large number of cavities are generated under the cavitation condition, and some of the voids are contained by the vortex to form a cavitation vortex