Abstract
The cavity flow is not only a fundamental problem in fluid dynamics, but also an important engineering problem. One of the actual problems of the cavity flow is pressure disturbance or acoustic noise generated in a duct with a cavity. The fundamental mechanism of pressure disturbance or noise generation in the cavity flow has been investigated. However, the structure of cavity flow depends on the shape of it and the flow condition in the duct. The flow in an axially symmetric cavity is not the same with the flow in a rectangular cavity. In this report, the flow in an axially symmetric cavity is investigated experimentally by using high-speed-video PIV. The results obtained by time series measurements of the flow show that the unsteadiness of the cavity flow depends on the cavity ratio and the circumferential structure of the flow must be considered.
