Flow around a Columnar Body with the Separated Shear Layer Excitation ( The Case of a Triangular Prism )

Abstract

In this study, we investigate flow control around a triangular prism in a uniform flow by utilizing receptivity to an external acoustic disturbance; we also investigate the mechanism of this flow control. The mean pressure fields on a prism surface are measured and the velocity fields around it are carefully investigated using Single type and X-type hot-wire probes. When a disturbance corresponding to the instability of a separated shear layer is added to a flow, the growth and the three-dimensionalization of the shear layer vortices related to flow randomization changes. Consequently, as the position of the Karman vortex shedding and the spanwise correlation of the vortex structure are changed, the force exerted by a fluid increases or decreases depending on the frequency of the disturbance.