钝体尾迹区通气空泡流动特性研究

In this paper, the characteristics of ventilated cavitating flow in the wake over a bluff body were investigated by experimental method. The flow pattern map of ventilated cavitating flow at different flow conditions is obtained. They are classified into two different categories: vortex shedding type and relatively stable type. When the gas entrainment coefficient is 0.0866, the flow patterns are all belonged to vortex shedding type, even if the Reynolds number changes. When the gas entrainment coefficient is 0.278, there is a ventilated cavity attached the bluff body. Under the circumstances, with the increase of Reynolds number the length of the cavity decreases significantly, and it changes from the relatively stable type to the vortex shedding type. When the Reynolds number remains fixed, with the increase of gas entrainment coefficient, the vortex shedding type would transform to the relatively stable type. In addition with the increase of Reynolds number, the critical value of gas entrainment coefficient for change the flow patterns increases.