Experimental Investigation of the Effect of Copper Nanowires On Heat Transfer and Pressure Drop For A Single Phase Microchannel Heat Sink
This thesis experimentally investigates the heat transfer and pressure drop characteristics of a shallow rectangular single phase microchannel heat sink with hydraulic diameter of 0.672 mm and whose bottom wall is coated with Cu nanowires (CuNWs) of 200 nm in diameter and 0.050 mm 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 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. Whereas an increase in pressure drop is observed in all test cases due to enhanced roughness. The enhanced thermal performance is possibly attributed to two properties of Cu nanowire arrays- improvement in surface wettability characteristics and enhanced heat transfer area. The surface morphology of the heat sink has also been studied before and after heat transfer experiments through SEM to assess any effect of fluid flow. The SEM results demonstrate no notable change in surface morphology within the Re range in which experiments have been conducted. The presented innovative scheme has the capability to dissipate higher heat flux per unit area and can be extended to two phase microchannel heat sink.
Engineering, Mechanical Engineering, Cu nanowires, enhanced thermal performance, microchannel heat sink
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