Two-phase pressure drop of air–water in minichannels

Results of experimental investigations of pressure drop in two-phase adiabatic flow in tubular minichannels are presented. Air–water mixture was used as a working fluid. Eight tubular minichannels with internal diameter dw = 1.05 ÷ 2.30 mm and the test section length of 300 mm made from stainless steel were used. The investigations were conducted within the range: mass flow rate of water 0.65 ÷ 59 kg/h, mass flow rate of air 0.011 ÷ 0.72 kg/h, mass fraction of air in the two-phase mixture x = 0.0003 ÷ 0.22, total mass flux (wρ) = 139 ÷ 8582 kg/(m2 s). It was found, on the basis of the experimental investigations, that the application of commonly used methods to evaluation of pressure drop in two-phase flow, provided poor results. It is therefore necessary to make some corrections and modifications for the two-phase flow in minichannels correlations.