Numerical investigation of heat transfer using impinging jets on triangular and square ribbed roughened walls

This paper presents a heat removal study on triangular and square ribbed surfaces under an array of impinging air jets. the investigation was carried out using nozzles with a 7x3 rectangular array of circular jets. the effect of re number,jet-to-plate distance,and rib arrangement on heat transfer and fluid flow characteristics was examined numerically. two arrangements have been studied. arrangement a considers the situation when the cooling jets are directed towards the ribs,while arrangement b considers the situation when the jets are directed towards the centre line of the cavity between two ribs. wall jets of neighboring jets have a stronger interaction with increasing reynolds number. the lowest and highest local heat transfer for all rib geometries was obtained for h/d=8 and h/d=4-6,respectively. on triangular ribbed surfaces the stagnation point nusselt number values for arrangement a are significantly higher than the stagnation point nusselt numbers for arrangement b. © 2017 tibtd printed in turkey.