Studies on the Fluctuation of Pressure Drop in Two-Phase Slug Flow : 3 rd Report, Pressure Recovery behind a bubble, and Lengths of Bubble and Liquid Slug

Abstract

The variation of pressure difference in a vertical tube when a single gas bubble rose in still water, was investigated experimentally and theoretically, as a fundamental study of two-phase slug flow. The pressure recovery Δp_R due to the momentum of liquid film around a gas bubble was studied experimentally. It was shown that Δp_R is about 30 kg/m² or less theoretically, and agrees with the experimental value. Moreover the theory was extended to the general two-phase flow, and the results that Δp_R takes a value of 40∼50 kg/m², was obtained experimentally and theoretically. And also the statistical characteristics of the lengths of bubble and slug were described, which were used in the analysis of the fluctuation of pressure drop in the 1st and 2nd reports.