Study of Fluid Flow and Heat Transfer In Circular Micro Channel

The computational fluid dynamics (CFD) model equations are solved to predict the hydrodynamic and thermal behavior of the exchanger. The geometry of the problem and meshing of it have been made in ANSYS 14.0. The models have been solved by ANSYS Fluent 14.0 solver. Water and its nanofluids with alumina (A2O3) are used as the coolant fluid in the microchannel heat sink. The present CFD calculated heat transfer coefficient values have compared with the analytical values and very close agreement is observed. The relation between heat transfer coefficient and thermal conductivity of the fluid i.e. h � k is proved in the present study. Thus use of nanofluids has been found beneficial both in laminar and turbulent zone. The result shows that nanofluids help to increase the heat transfer coefficient by 15% and 12% respectively in laminar and turbulent zone. The entrance length for the fully developed velocities depends on Reynolds number. The experimental work done by Lee and Mudawar (2007) has been predicted by the present CFD results. The hydrodynamics and thermal behaviour of a rectangular microchannel are studied here. The variation wall temperature, pressure drop in the channel and the friction factors calculated using ANSYS Fluent can well predict the experimental data. The effect of Re on the behavior the channel are also studied. Its behavior also have been analysed with the help of temperature, pressure and velocity contours.