On Numerical Investigation of Nusselt Distribution Profile of Heat Sink Using Lateral Impingement of Air Jet

Introduction Study of heat transfer augmentation using steady air jet impinging over the heat sink finds abundant applications in material processing industries, drying technologies and electronic packaging systems. As far as the efficiency of these appliances is concerned, determination of local cooling rate due to the impingement of air jet plays a bottom line role. This is regarded as one of the best attempts to replace noisy components like fans and blowers in the cooling technologies. Cooling of these appliances in the electronic system using air jet gives comparatively higher cooling rate as that achieved by conventional cooling practices. The advancement of cooling technology in electronic packaging systems and material processing industries recently demanded the practice of non-uniform cooling rate to be established over the heat sink. The benefit of non-uniform cooling rate in material processing industries was achieving variable metallurgical properties. In order to measure the degree of non-uniformity occurring in the cooling rate, determination of local heat transfer coefficient becomes mandatory. For the benefit and feasibility in the study and development of empirical correlations, a non-dimensional parameter representing heat transfer is mandatory to be introduced. In this study, Nusselt number is the non-dimensional parameter used to represent the cooling rate. The plot of Nusselt magnitude against the radial distance of target surface truly justifies the degree of non-uniformity occurring in the cooling rate. As far as the determination of cooling rate is concerned, experimental as well as numerical analysis is extensively carried out. For experimental study, the basic setup comprises of an air impinging nozzle and a target surface. Constant heating is ensured at the bottom side of the target surface, while the other side is exposed to air jet. It is true that the effort required in performing the experiment is enormous, since the temperature of target surface is initially in a transient state. Hence, numerical analysis is recommended.
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