ISI BILIMI VE TEKNIGI DERGISI-JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY, vol.37, no.1, pp.13-24, 2017 (SCI-Expanded)
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.