SOME INVESTIGATIONS ON TWO-PHASE UPWARD FLOW IN SMALL CHANNELS AT SMALL MASS FLUXES

This paper presents adiabatic two-phase pressure drop measurements in vertical upward flow in small channels at small mass fluxes. The measurements show a mismatch between the measured and the predicted pressure drops at these conditions. The paper demonstrates that normal two-phase pressure drop correlations based on the slip ratio fail to predict the liquid hold-up for small mass fluxes. A modification, which improves the agreement with experimental data, is developed in the paper.