Optimization of Fin Performance in a Laminar Channel Flow Through Dimpled Surfaces

摘要

The effect of the dimple shape and orientation on the heat transfer coefficient of a vertical fin surface was determined both numerically and experimentally. The investigation focused on the laminar channel flow between fins, with a Re =500 and 1000. Numerical simulations were performed using a commercial computational fluid dynamics code to analyze optimum configurations, and then an experimental investigation was conducted on flat and dimpled surfaces for comparison purposes. Numerical results indicated that oval dimples with their "long" axis oriented perpendicular to the direction of the flow offered the best thermal improvement, hence the overall Nusselt number increased up to 10.6% for the dimpled surface. Experimental work confirmed these results with a wall-averaged temperature reduction of up to 3.7 K, which depended on the heat load and the Reynolds number. Pressure losses due to the dimple patterning were also briefly explored numerically in this work.