SCHOOL OF MECHANICAL ENGINEERING SEMINAR Monday, June 25, 2012 at 15:00 Wolfson Building of Mechanical Engineering, Room 206

Ph.D. student of Prof. Lev Shemer, School of Mechanical Engineering, Tel-Aviv University

Two-phase gas liquid pipe flow is studied experimentally by quantitative measurements of the cross sectional distribution of phases within the pipe. A wire mesh sensor is used for this purpose. The wire-mesh sensor can be seen as an intrusive tomograph with high sampling frequency. The accumulated records of the sensor allow one to obtain cross sectional phase distribution information leading to an ability to reconstruct the 3D structure of the phase distribution in a pipe.

In the current research slug flow was thoroughly investigated. Experiments were carried out in two 10 m long pipes with different internal diameters. Inclined and vertical with co-current upward and downward water-air flows were investigated. The effect of different pipe inclinations and flow conditions on gas-liquid distribution within the pipe was experimentally studied. In addition to the wire mesh sensor, conductance probes were used to provide measurements of the gas-liquid interface propagation velocity, which is crucial for quantitative reconstruction of the 3D picture of two phase pipe flow.

Processing of the wire-mesh sensor data was applied to carry out statistical analysis of characteristic parameters of slug flow. Information on elongated bubble and liquid slug lengths distributions, as well as the ensemble-averaged elongated bubble and liquid slug parameters were obtained. Detailed analysis of the 3D void distribution along the liquid slug was presented. The elongated bubble was characterized by shapes of the bubble nose, bubble tail, as well as the liquid film thickness along the representative elongated bubble. Moreover, the gas volume was determined in the representative slug unit. The representative 3D structure of an elongated bubble in slug flow is obtained. The current research findings were compared to theoretical models and available data in literature.

Hydrodynamic Characteristics of Gas-Liquid Slug Flow in Pipes

Elena Roitberg