Light oil-gas two-phase flow pattern identification in different pipe orientations: An experimental approach

In this paper, an experimental study on the flow patterns of two-phase air-light oil flow is performed in a 20 mm diameter pipe with a length of 6 m in different orientations with pipe angles in the range of -45 to +45. The flow regimes are captured by a high-speed camera. In the experiments, the following are used: the air with the viscosity of 0.019 mPa.s and the density of 1.2 kg/m as well as the light oil with the viscosity of 2.6 mPa.s and the density of 840 kg/m3. During the experiments, different flow patterns are observed such as bubbly, slug, smooth stratified, wavy stratified, and annular flows. Flow regimes in different pipe inclination angles are inspected in a two-phase air-light oil flow, and flow pattern maps are proposed for every pipe inclination angle. In addition, a comprehensive study on the major forces acting on dispersed phase is presented theoretically to perform a thorough discussion on the effects of pipe inclination angle on transition boundaries between flow patterns in the two-phase air-light oil flow. It is inferred that non-stratified flows are dominant flow patterns in the upward flows, and stratified flows are dominant flow patterns in the downward flows. © 2017 Sharif University of Technology. All rights reserved.