Fluid dynamic analysis and heat transfer of the inclined impingement cooling in a channel backward facing step

Abstract

In this paper, a computational investigation has been performed to analyze the turbulent flow characteristics inside a channel backward facing step under an inclined impingement cooling. The impinging jets were inclined towards the upstream cross flow and the angle of inclination was varied from 30° to 90°. The effect of an inclination angle, the size of slot jets and the contraction ratio on the flow and thermal field was examined. The governing elliptic Navier-Stockes, energy and turbulence model equations were discretised by using a finite volume method. The k-e model was used to model the turbulence. A computer program was developed to solve these equations by using the SIMPLE algorithm with a staggered grid technique. The aim of this paper is to show how the inclined impingement cooling inside a channel backward facing can represent a significant factor to enhance the rate of heat transfer and producing complex flow field features. The computed results show that the size and strength of recirculation regions are increased as angle of inclination increases. Such increase is also found with increasing the contraction ratio (SR). However this effect seems to be little compared with angle of inclination. The local rate of heat transfer is enhanced as the angle of inclination increases. The validation of the present scheme is performed through comparison with available published results.