Effect of surface modification of a rectangular vortex generator on heat transfer rate from a surface to fluid

Abstract

Surface cooling is an essential tool in many industrial applications. Effective utilization of the wetted surface area is an important factor in the heat transfer enhancement. It may be done by optimizing the shape of the extended surfaces meant for increasing the thermal diffusion, or by improving the thermal interaction between the solid and the fluid. Creation of differential pressure using vortex generator may improve the way the thermal energy is exchanged. It may be obtained by reenergizing the boundary layer using the generated vortices. In the present work the effect of surface textures of the vortex generator on heat transfer and vortex dynamics are studied. The CFD results show that multiple and single texturing on the leading and the trailing faces of the vortex generator, respectively, can enhance the primary vortex downstream of the vortex generator. This in turn enhances the heat transfer by increasing the average Nusselt number and the skin friction coefficient of the plate. The surface temperature is also found to be reduced by the stretching of the vortex with a minimal pressure drop.