Simulation of Evaporation Heat Transfer in a Rectangular Microchannel

Due to high heat transfer coefficient and compactness of the system, microchannel based cooling and heating techniques have immense prospect in dissipating high heat flux from electronic device. In respect of cooling performance, two-phase evaporative flow or flow boiling in microchannel is more effective than the single phase flow due to involvement of latent heat in the process. In this paper a numerical model is proposed to simulate evaporation heat transfer of a multiphase flow in a channel using different boundary conditions at channel walls. Volume of fluids approach was used which governs the hydrodynamics of multiphase flow. The source terms accounting for the energy and mass transfer at the interface of the liquid and vapor were included in the governing equations for conservation of energy and volume fraction. A two dimensional microchannel of length 1000 μm and hydraulic diameter of 100 μm was developed in ANSYS FLUENT 14.0. The fluid used was water and the liquid mass flux at inlet was given as 1 kg/m2s. Results were analyzed in terms of the variation of volume fraction of vapor at different locations along the microchannel