Heat Transfer Intensification of a Confined Impinging Air Jet via a Guiding Baffle

The heat transfer intensification of a confined imping jet was achieved using rough surface, pin fines as well as using modified nozzle such as chamfering, chevron, sweeping, swirling, etc. In the current work, the enhanced cooling process utilizing a single confined air jet impinged on a flat plate using a guiding baffle is implemented. The impacts of Reynolds number (Re) ranged from 500 to 5000, guiding baffle diameter-to-nozzle diameter (D/d) of 2, 4, and 6, and guiding baffle height-to-nozzle to impinging plate distance (h/H) of 1/3, 1/2, and 3/4 on the cooling process are studied. The distributions of surface temperature are acquired experimentally using the thermal infrared camera. As well, the local Nusselt number,(Nu) stagnation Nusselt number (Nu¯st), average Nusselt number,(Nu¯) and average Nusselt number ratio (Nur¯) are evaluated. The results reveal that the enhancement of heat transfer is achieved due to installing a baffle with a D/d of 2 for all values of baffle height and Reynolds number. In addition, the (Nur¯) is increased with increasing the Re in the range from 500 to 2500, then it is decreased by a further increase in in Re. Moreover, based on the experimental results, an empirical correction is proposed to compute (Nu¯) the average Nusselt number depending on Re, D/d, and h/H with a ± 2.65% standard deviation.