A Preliminary Study of the Transition of an In-Line Pipe Vortex to Slug Flow Using Particle Image Velocimetry

In this preliminary work, the performance of a Slug Flow Expander (SFE) was investigated. Multiphase flows consisting of air and water were injected into the SFE, a device designed to generate quality slug flow at regular intervals. It was observed that for water flow rates of 1.25 L/s & 1.50 L/s combined with air flow rates above 1.0 L/s, the flow regime within the SFE transitioned to slug flow. A LaVision Flowmaster3 stereo digital PIV system was used to perform two-component velocity measurements on the SFE design prototype. The current investigation focused on discerning the velocity profile of the liquid component within the SFE. Radial and azimuthal velocity components were extracted from the mean velocity field data. Circulation and vorticity were then computed from the azimuthal velocity component by Stokes theorem, and were used to characterize the flow physics of the liquid component as a function of increasing air flow rate. It was found that the velocity profile may be closely approximated with an Oseen vortex.