Experimental investigation of the effect of copper nanowires on heat transfer and pressure drop for a single phase microchannel heat sink.

摘要

This thesis experimentally investigates single phase heat transfer and pressure drop characteristics of a shallow rectangular microchannel heat sink whose surface is enhanced with copper nanowires (CuNWs). The hydraulic diameter of the channel is 672 mum whose bottom wall is coated with Cu nanowires (CuNWs) of 200 nm in diameter and 50 mum in length. CuNWs are grown on Cu heat sink by electroplating technique which is inexpensive and readily scalable. The heat transfer and pressure drop results of CuNWs enhanced heat sink are compared with that of bare copper heat sink using deionized (DI) water as the working fluid at Reynolds Number (Re) ranging from 106-636. The experimental results indicate an enhancement in Nusselt Number (Nu) at all Re with a maximum enhancement of 24% at Re = 106. It is also observed that there is an increase in pressure drop in all test cases due to enhanced roughness.;The enhanced thermal performance is attributed to two properties of Cu nanowire arrays---improvement in surface wettability characteristics and increased heat transfer surface area. The surface morphology of the heat sink has also been studied before and after heat transfer experiments through SEM to assess the effect of fluid flow on CuNWs. The SEM results demonstrate no notable changes in surface morphology for the Re range in which experiments have been conducted.