绕空化器回转体非定常通气空化流动特性的实验研究

为了研究绕回转体通气空化流场特性，以带空化器回转体为研究对象，采用实验的方法运用全流场流动显示技术获得了不同条件下的空泡形态、流场结构。研究结果表明：在相同傅汝德数下，空泡形态随通气率的增大而增大，从最初的游离空泡发展成超空泡，在超空化阶段的显著特点是在主流区和超空化区之间存在着光滑而清晰的分界面，空泡的稳定性增强；在相同通气率下，空泡形态随傅汝德数的增大而减小，由于空泡界面的滑移速度增大，通入的定量气体来不及聚积成大的空泡而被高速来流带到流场的下游，使得泄气量加大；通气空化流场呈现非定常特性，其反向射流的推进速度随通气率的增大而增大。

Experimental Study on Unsteady Ventilated Cavitating Flows around an Axisymmetric Body with Cavitator

The unsteady characteristics of ventilated cavitating flows around axisymmetric body with a cavitator are addressed by using experimental methods. Cavities around the body are observed by means of a high-speed video camera in the different conditions. The results show that the shapes of the cavities increase with the increase in ventilation rate at the same Froude number, and they develops from the free cavities to the supercavities. In the supercavitating flow stage, a smooth and clear interface exists between main stream and supercavitating region. The cavity shapes decrease with the increase in Froude number at the same ventilation rate. The ventilated air doesn’t form a big bubble because the air flows to downstream of flow field with the high speed flow. The unsteady characteristics can be observed in ventilated cavitating flow field. The velocity of re-entrant jet increases with the increase in ventilation rate.