Experimental and numerical investigations of local condensation heat transfer in a single square microchannel under variable heat flux

This paper presents an experimental investigation on the local and average condensation heat transfer in a single noncircular microchannel. Furthermore, it develops one dimensional model for annular condensation flow in a microchannel under variable heat flux condition. The condensate film thickness is calculated for each location in a microchannel including the effects of capillary number, Boiling number, contact angle, heat flux, vapor pressure, and hydraulic diameter. A comparative study shows that the present model well predicts the experimental data concerning local condensation heat transfer coefficient. The mean deviation between the local predictions of the theoretical model with the measurements for local heat transfer coefficient is 20%. It is found that the correlation of Quan et al. (2008) [19] gives the good predictions of the measurements with maximum deviation of 13% at high Reynolds number.