Effect of winglet vortex generators configuration on thermal performance of a heated rectangular channel

Abstract

In present paper, a three dimensional turbulent flow; and heat transfer inside a rectangular  channel equipped with array of winglet vortex generators has been investigated experimentally and numerically. Three pairs array of winglet vortex generators of different geometrical configuration  as rectangular, triangular, semi circle and parabolic are considered. The array of winglet vortex generators is formed and distributed on the bottom hot surface with a facility for changing the angle of attack from (0° to 60°). ANSYS Fluent Code (15.0) based on a finite volume method is used to get the numerical results while a k-w turbulence model is used to model the turbulent . The Reynolds number range is from 10000 to 50,000 under a constant heat flux boundary condition. The spin wise between the vortex generators are set to 1 cm and  1.5 cm while the stream wise between the vortex are 9cm,12cm and 18 cm respectively. The results indicated that the rectangular winglet vortex generators array indicated the optimum thermal performance with considerable penalty of the pressure  drop while the parabolic vortex generator stated the minimum performance among the considered vortex generators shapes. The overall efficiency  for rectangular, triangular, semi circle and parabolic winglet vortex generators is enhanced by (166%), (130%), (165%) and (121%) respectively as compared with plane channel.