Experimental Investigation of Heat Transfer Enhancement from Pin Fins with Delta Winglet Vortex Generators in Square Channel
Study has been carried out in a 50 mm × 50 mm test section to understand the influence of delta winglet vortex generators on heat transfer characteristics in a square channel. Reynolds number based on the hydraulic diameter is varied from 8000 to 20000. With constant heat flux, experiment was performed to calculate heat transfer characteristics by installing pin fins and delta winglet vortex generators on the flat plate. The horizontal pitch of pin fin is varied by 18 mm, 20 mm and 22 mm. Then delta winglets were installed on the finned plate with angle of attack varied from 30º, 45º and 60º. After test setup validation, experiment was conducted and test results were compared with the flat plate results. From experiment it is found that the heat transfers increases by using delta winglet vortex generators. Best results are obtained for Re 20000 with 18mm pin fin pitch having angle of attack of 45º, Enhancement ratio was found to be 3.77 on account of pressure drop across the test section. Thermo Hydraulic performance (Nu/Nu0)/ (f/f0)1/3 were found 2.96. So from the experiment it is concluded that by using delta winglets, heat transfer enhances without severe penalties associated with the pressure drop.
Swapnil Gajanan Chitnis* and Sandeep S Kore
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