Comparative Study of Heat Transfer Performance of Open and Closed Rectangular Microchannel Heat Sink

Numerical simulations have been performed to investigate the heat transfer and coolant flow behaviour in open and closed configurations of parallel rectangular microchannel heat sink. Height of the fins is slightly shorter in open microchannel heat sink which provides open space between fin top surfaces and cover wall. Open microchannel holds fin height of 0.8 mm in comparison to 1.0 mm for closed configuration. Three dimensional (3D) numerical simulations were carried out for both heat sink geometries. Operating range of Re is 100-400 and applied heat flux range is 100-500 kW/m(2). Thermal performance of the heat sink has been analysed through predicted results of temperature distribution, heat transfer coefficient, pressure drop and flow behaviour of the coolant in microchannel. Comparative study reveals that open microchannel heat sink has higher potential to dissipate more heat compared to its counterpart. It is due to the availability of open space at the fin top which provides distinct flow behaviour of coolant that support favourable circumstances for higher heat transfer.