Investigations of flow phenomena behind a flat plate with circular trailing edge

Abstract

The present study investigates the effect of circular trailing edge on the complex flow phenomena occurring in the near-wake, nearer far-wake and far-wake zones for different Reynolds numbers and angles of attack. The velocity vector depicts that the maximum lift is obtained when the leading-edge vortex attains maximum size, whereas the minimum lift is achieved when the trailing-edge vortex attains maximum size. The near-wake zone extends up to an x/c value of 1.2; thereafter, it undergoes transition for the range of x/c values from 1.2 to 7 and beyond an x/c value of 7, the far-wake zone begins where the complex nonlinear flow phenomena occur, (x is the streamwise distance from the circular trailing edge, and c is the chord length). The spectra reveals the formation of primary vortex shedding with single dominant frequency in the near wake, whereas two dominant frequencies correspond to the primary vortex shedding as well as secondary large-scale oscillations, in the far wake. In the near-wake vortices convect alternately while in the far-wake vortices of opposite sign move in pairs and undulates at low frequency without remaining fixed at the centerline of the circular trailing edge.