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

The heat transfer intensification of a confined impinging jet was achieved using a rough surface or pin fins as well as using modified nozzles such as chamfering, chevron, sweeping, swirling, etc. In this work, an 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-tonozzle 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 a thermal infrared camera. As well, the local Nusselt number (Nu), stagnation point Nusselt number (Nust), average Nusselt number ((Nu) over bar), and average Nusselt number ratio ((Nu) over bar (r)) are evaluated. The results reveal that the enhancement of heat transfer is achieved due to installing a guiding baffle with a D/d of 2 for all values of baffle height and Reynolds number. In addition, the (Nu) over bar (r) is increased with increasing the Re in the range from 500 to 2500, then it is decreased by a further increase in Re. Moreover, based on the experimental results, an empirical correlation is proposed to compute the (Nu) over bar depending on Re, D/d, and h/H with a +/- 62.65% standard deviation.