Horizontal air- water flow pattern recognition

Wire Mesh Sensor (WMS), based on the measurement of the local instantaneous conductivity of the two-phase mixture, has been adopted to characterize the air-water flow in a test section consisting of a horizontal Plexiglas (transparent) pipe of internal diameter 19.5 mm and total length of about 6 m. The flow quality ranges from 0 to 0.73 and the superficial velocity ranges from 0.145 to 31.94 m/s for air and from 0.019 to 2.62 m/s for water; the pressure ranges from atmospheric pressure to 3.7 bar. The observed flow patterns are stratified-bubble-slug/plug-annular. The void fraction profiles are derived from the sensor signals and their evolution in time and space is analyzed and discussed; the dependence of the signals on the measured fluid dynamic quantities is discussed too