Determination of Lockhart-Martinelli parameter using CFD in 2D vertical rectangular and offset mini-channels with R717

Abstract

Study of mini-channels has become more popular in the current scenario due to the increasing developments in the field of compact heat exchangers due to the inherent property of increased heat transfer coefficients. Two types of vertical mini-channels, rectangular and offset channels are studied at six different configurations. The flow properties are analyzed using commercial CFD code by varying hydraulic diameters from 1 – 3 mm and mass flux from 5 – 75 kg/m2s. The friction factor is determined using CFD in two dimensional steady state conditions. The results are compared with available empirical correlations. Modified correlations are proposed for friction factor to determine Lockhart-Martinelli parameter based on CFD results. The Lockhart-Martinelli parameters are determined from modified friction factor correlations. © Research India Publications.