Flow pattern and water holdup measurements of vertical upward oil–water two-phase flow in small diameter pipes

• Published in: International journal of multiphase flow Vol. 41; pp. 91 - 105
• Main Authors: Du, Meng, Jin, Ning-De, Gao, Zhong-Ke, Wang, Zhen-Ya, Zhai, Lu-Sheng
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2012; Elsevier
• Subjects: Exact sciences and technology; Flow pattern map; Fluid dynamics; Fundamental areas of phenomenology (including applications); Instrumentation for fluid dynamics; Multiphase and particle-laden flows; Nonhomogeneous flows; Physics; Time–frequency representation; Vertical oil–water flows; VMEA sensor; Water holdup; Water holdup; Flow pattern map; Time–frequency representation; VMEA sensor; Vertical oil–water flows; Water; Test facilities; Oils; Vertical pipe; Circular pipe; Measuring methods; Experimental study; Time-frequency representation; Flow regime; Two-phase flow; Liquid liquid interface; Vertical oil-water flows; Sensor array
• ISSN: 0301-9322; 1879-3533
• DOI: 10.1016/j.ijmultiphaseflow.2012.01.007

► We propose a criterion of vertical oil-water flow pattern transition. ► We extract total energy and time-frequency entropy to characterize flow patterns. ► The conductance method is a good way to measure two-phase flow characteristics. We experimentally investigate vertical upward oil–water two-phase flow in a 20mm inner diameter pipe. We first using vertical multiple electrode array conductance sensor measure the water holdup, and using mini-conductance probes define five observed flow patterns, i.e., very fine dispersed oil-in-water (VFD O/W) flow, dispersed oil-in-water (D O/W) flow, oil-in-water slug (D OS/W) flow, water-in-oil (D W/O) and transition flow (TF). Then we present an experimental flow pattern map with oil and water superficial velocity ranging from 0.258m/s to 3.684m/s and 0.184m/s to 1.474m/s, respectively. In addition, we obtain the flow pattern transition boundaries in terms of water holdup. Finally, we propose an effective quadric time–frequency representation, i.e., the adaptive optimal kernel time–frequency representation (AOK TFR) to investigate the complex behavior underlying vertical upward oil–water flow. In particular, we extract total energy and time–frequency entropy to characterize the evolutions of flow patterns. The results suggest that AOK TFR based method could potentially be a powerful tool for characterizing the dynamical characteristics of different vertical upward water-dominant oil–water flow patterns.