ENHANCEMENT OF HEAT TRANSFER PERFORMANCE IN AN ALUMINUM HEAT SINK USING DIFFERENT NANOCOATINGS

The recent pioneering advancement in nanotechnology paves the way to further enhance the heat transfer in heat sinks, through various types of nanocoatings. In the present work an aluminum pin-fin heat sink was identified, for the performance enhancement through three different high thermal conductivity material (Cu, Ag, Al)-based nanocoating. The surface characteristics of the coated samples were compared with the uncoated sample and the performance evaluation of the heat sink with and without coating under forced convection conditions were studied. The increase in surface roughness disturbs the thermal boundary layer growth, which in turn increases the surface convection heat transfer coefficient. The increased roughness also enhances the exposed heat transfer surface area. The times required for the coated heat sink surfaces to reach 70°C are nearly 2.7- to 3.15-fold higher than the uncoated heat sink at 27°C and are nearly 1.75- to 2.85-fold higher than the uncoated heat sink when the surrounding temperature is maintained at 31°C. The said effects are higher in the aluminum-coated heat sink than the other surface-treated cases as there is a good mechanical bonding established between the aluminum heat sink and coating due to similar material.