Modeling of Interfacial Component for Two-Phase Frictional Pressure Gradient in Microchannels and Minichannels

A simple approach for calculating the interfacial component of frictional pressure gradient in two-phase flow in microchannels and minichannels is presented. This approach is developed using superposition of three pressure gradients: single-phase liquid, single-phase gas, and interfacial pressure gradient. The proposed model can be transformed in two different ways. First, two-phase interfacial multiplier for liquid flowing alone (⁠$φl,i2$⁠) as a function of two-phase frictional multiplier for liquid flowing alone (⁠$φl2$⁠) and the Lockhart-Martinelli parameter, X. Second, two-phase interfacial multiplier for gas flowing alone (⁠$φg,i2$⁠) as a function of two-phase frictional multiplier for gas flowing alone (⁠$φg2$⁠) and the Lockhart-Martinelli parameter, X. This proposed model allows for the interfacial pressure gradient to be easily modeled. Comparisons of the proposed model with experimental data for microchannels and minichannels and existing correlations for both φ_l and φ_g versus X are presented.