DIRECT IMAGING OF 2-PHASE FLOWS BY ELECTRICAL-IMPEDANCE MEASUREMENTS

This paper presents a two-phase flow direct imaging sensor, based on m ultiple electrical impedance measurements. The electrode configuration is optimized to provide imaged information on the phase distribution within the probe's sensing volume, As a consequence, the time evolutio n of the flow topology can be represented by simply plotting the signa ls corresponding to the peripheral impedance measurements, and therefo re needs no numerical reconstruction from the experimental data, Sever al transient tests are performed in a two-phase air-water loop. They d emonstrate that the sensor exhibits not only large structures such as slugs and plugs, but also some finer details such as the wavy or rugge d interface in stratified flow, or liquid film drainage during the tra nsition between intermittent and annular flows, The methodology propos ed in this work constitutes a simple and inexpensive alternative to to mographic imaging techniques, and is thus fully adapted to online proc ess monitoring of multiphase flow systems.