Studies on the Fluctuation of pressure Drop in Two-Phase Slug Flow : 1 st Report, Experimental Study

Abstract

Experimental and theoretical studies of the fluctuation of air-water two-phase slug flow in a vertical tube, have been described in three papers. Among them, the experimental results are presented in this paper. It was verified that the time variation of pressure drop is predicted by the variation of lengths of gas bubble and liquid slug flowing in the tube. It was also shown that the probability distribution of pressure drop in long segments of tube is normal distribution, and that in short segments, distribution has generally two peaks at Δp^* (i.e., dimensionless pressure drop) =0 and 1. The maximum amplitude of the pressure drop was given by the following empirical equation δΔp_max^*/Δp_m^*=0.7L_T^-0.62w_l0^-0.62w_g0^0.9 where, δΔp_max^* and Δp_m^* are the maximum amplitude and the mean value of dimensionless pressure drop, respectively; w_l0 and w_g0 superficial liquid and gas velocity, respectively; and L_T is the length of segment of tube.