Characteristics of frictional pressure drop of two-phase nitrogen flow in horizontal smooth mini channels in diabatic/adiabatic conditions

The two-phase frictional pressure drop of nitrogen under diabatic and adiabatic conditions is investigated experimentally in two horizontal mini channels. The effects of factors in a variety, including the channel diameter, mass flux, heat flux, inlet pressure and vapor quality are examined on the frictional pressure drop and liquid-phase multiplier of the two-phase flow. The two-phase frictional pressure drop predicted by previous correlations from other studies are compared with the experimental results of this study, and the lowest mean absolute deviation is 18.3% for adiabatic conditions and 10.9% for adiabatic conditions. Based on the experimental results of nitrogen flow, two new correlations in the form of the Chisholm-C correlation are developed to predict the two-phase frictional pressure dropby involving the effect of surface tension, and the mean absolute deviation of which is 12.3% and 10.4% for the adiabatic and diabatic conditions respectively. The new correlations are also shown able to well predict the experimental frictional pressure drop of other studies under different experimental conditions.