Experimental investigation of heat transfer enhancement through embossed fin heat sink under natural convection

Artificial surface irregularity in the form of embossed impressions is an effective technique to enhance heat transfer rates from the surface. The present study explores the heat transfer characteristics of embossed heat sink having repeated impressions on the fin surface subjected to natural convection. Heat transfer performance of the embossed fin heat sink is expressed as the Nusselt number enhancement ratio and embossed fin effectiveness for the range of impression angle from 30° to 90° while impression pitch is considered as 12 mm, 16 mm and 20 mm under different heat input rates. A maximum enhancement in the Nusselt number for embossed fin is found to be 2.86 corresponding to the impression angle of 45° and impression pitch of 12 mm with regard to smooth fin.