Numerical Examination of Heat Transfer and Entropy Generation in Confined-Slot Jet Impingement Featuring Wing Ribs

Abstract

In this study, a numerical investigation into heat transfer and entropy generation characteristics using confined-slot jet impingement was conducted. Comparisons were drawn between the heat transfer and entropy generation attributes of two wing ribs positioned on the heated impinging target surface and those of a rib-less surface. The influences of variations in the spacing between the stagnation point and the rib (B) of (10-30 mm), ranging from 10 to 30 mm, rib heights (A) between 0.5 to 2 mm, and a Reynolds number of the jet (Re) between 3000 to 8000 on fluid flow, heat transfer, and entropy generation were elucidated. Employing the Finite Volume Method (FVM) managed the continuity, momentum, and energy equations in adherence to the principles of the SIMPLE methodology. Results revealed that the Nusselt number $(\overline{N u})$, pressure drop, and total entropy $\left(\bar{S}_{\text {total }}\right)$ escalated in accordance with Re and A. Conversely, they diminished with reduced spacing from the stagnation point to B. Notably, a superior heat transfer rate was observed when employing a target plate integrated with wing ribs in contrast to a rib-less configuration. Performance Evaluation Criteria (PEC) values were noted to augment with rib height increment. It is demonstrated that the PEC increases as A increases. Also, the lower value of PEC equals 1.044 at A of 2 mm, B of 10 mm, and Re of 8000, while the higher value of the PEC equals 1.68 at A of 2 mm, B of 10 mm, and Re of 3000. The findings suggest that slot-Jet impingement complemented by wing ribs plays a pivotal role in enhancing the cooling efficiency of electronic devices.