Flow of Incompressible Two-Phase Mixtures through Sharp-Edged Orifices

Abstract

Equations are developed for the flow of gas-liquid or vapour-liquid mixtures through sharp-edged orifices under conditions where the density change of the gas or liquid through the orifice is negligible. The theoretical development differs from previous treatments in allowing for the interfacial shear force between the phases, and leads to an equation which is shown to be in good agreement with available experimental evidence. The determination by experiment of a single coefficient characterizing the pipe and orifice arrangement permits the prediction of both the two-phase flow rate and the ratio of the phase velocities for a given pressure drop and gas-liquid weight ratio. The range of conditions examined extends over weight ratios of gas to total mixture from 0·1 to 98 per cent, and ratios of downstream to upstream pressures greater than 0·99. The accuracy of correlation of two-phase flow data is now approaching that of single-phase flow.