Heat transfer analysis of square and circular perforated fines in stagged arrangement

Abstract

The experiment on heat transfer enhancement over a surface equipped with square and cylindrical pin fins with cylindrical perforations in a rectangular channel in a staggered manner. The channel has a cross-section of 100x250 mm2. The experiment covered the following range Re=13,500-42000, Clearance ratio=0, Inter –fin spacing Sy/D=1.208, 1.524. Co-relation equations were developed for the heat transfer, Friction factor, Effectiveness. The experimental result showed that the use of cylindrical fin gives the max heat transfer enhancement. Effectiveness varies from 1.1-1.5 depending upon the inter-fin spacing. The friction factor also decreases. Thus the maximum effectiveness is obtained at minimum velocity and more inter-fin spacing. The average Nusselt number calculated on the basis of projected area increased with decreasing inter-fin spacing ratio. The friction factor increased with decreasing inter-fin distance ratio. Enhancement efficiencies increased with decreasing Reynolds number. Therefore, relatively lower Reynolds number led to an improvement in the heat transfer performance.