Enhanced heat transfer in plate fin heat sink with dimples and protrusions

The heat transfer and flow performance of the plate fin heat sink in a horizontal rectangular channel with dimples and protrusions on the fin surfaces has been experimentally investigated in forced convection. The Nusselt number and friction factor are obtained by varying the system parameters as depth and pitch of the dimples for inline and staggered arrangements. The Reynolds number is considered in the range of 6800 to 15,200. The effect of depth and pitch of dimples are examined under constant heat flux while keeping the constant diameter of dimples. Experimental results indicate that the heat transfer and flow performance of fin array are significantly influenced by increasing the depth of dimples. The heat transfer from fin array is enhanced and the flow resistance is increased by decreasing the pitch ratio (s/d) and increasing the depth ratio (D/d). The maximum fin performance of dimpled fin heat sink corresponds to the staggered arrangement of dimpled heat sink with dimple pitch ratio (s/d) of 2.5 and dimple depth ratio (D/d) of 0.5.