A New Device for Gas-Liquid Flow Measurements Relying on Forced Annular Flow

Abstract

A new measurement device, consisting of swirling blades and capsule-shaped throttling elements, is proposed in this study to eliminate typical measurement errors caused by complex flow patterns in gas-liquid flow. The swirling blades are used to transform the complex flow pattern into a forced annular flow. Drawing on the research of existing blockage flow meters and also exploiting the single-phase flow measurement theory, a formula is introduced to measure the phase-separated flow of gas and liquid. The formula requires the pressure ratio, Lockhart-Martinelli number (L-M number), and the gas phase Froude number. The unknown parameters appearing in the formula are fitted through numerical simulation using computational fluid dynamics (CFD), which involves a comprehensive analysis of the flow field inside the device from multiple perspectives, and takes into account the influence of pressure fluctuations. Finally, the measurement model is validated through an experimental error analysis. The results demonstrate that the measurement error can be maintained within ±8% for various flow patterns, including stratified flow, bubble flow, and wave flow. KEYWORDS Gas-liquid flow measurement; blocking flowmeter; measurement model; pressure fluctuations; numerical simulation; experimental control Nomenclature Fr g Froude number Pr Pressure difference ratio ρ Fluid density (kg/m 3 ) β Equivalent diameter ratio This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.