Vortex shedding and tonal noise from a sharp bevelled trailing edge

Abstract

An incompressible numerical simulation of vortex shedding from a bevelled at plate in uniform ow is presented. The results are used to explain experimental observations regarding the radiated noise and velocity uctuations in the wake and boundary layers of the plate. Vortex shedding was found to occur from the trailing edge with frequencies dom- inated by three vortex shedding modes. The frequencies of these modes was determined by the trajectory of the shed vortices from the upper surface, with those occurring further from the surface associated with faster convective velocity and hence higher frequency. Weak convective disturbances from an upstream separation bubble are suspected to inter- mittently couple with the trailing edge vortex shedding process, disturbing the vortex as it forms to create the three observed modes. Further, analysis of numerical wake velocity data can explain low frequency peaks obtained experimentally. Finally, an acoustic analysis of the numerical data is used to explain the existence of the two major tones measured during experiment.