Two-phase pressure drop for gas and non-Newtonian liquid flows through circular microchannel

Abstract

This study investigated pressure drop for gas and non-Newtonian liquid two-phase flows in a horizontal circular microchannel. The microchannel was a fused silica tube with 0.25 mm I.D. Polyacrylamide aqueous solutions with different mass concentration, which exhibit pseudo plastic behavior, were used as non-Newtonian liquid, while the nitrogen gas was used as the test gas. Pressure drop was measured with a calibrated differential pressure transducer. The pressure drop data have been compared with calculations by various correlations, usually used for prediction of the pressure drop in mini/micro channels as well as conventional sized channel. As the comparison results, the data have been correlated with separated flow model by using a newly developed equation of two-phase friction factor as well as homogenous flow model with an effective viscosity accounting for non-Newtonian effects. The Lockhart-Martinelli model also predicted well the present data if an appropriate C-value in two-phase friction multiplier was adopted.