Determination of velocity and angular displacement of bubbly flows by means of wire-mesh sensors and correlation analysis

For the analysis of air–water bubbly flows in vertical pipes a method is presented which determines the radial profiles of velocity and angular displacement of the gaseous phase. Measurements rely on two so-called wire-mesh sensors, put into the flow behind each other and capturing the electrical conductivity distribution in the pipe cross-section at two different axial positions. The time-resolved signal is directly translated into transient two-dimensional distributions of the gaseous phase at both sensor positions. Sensor data analysis is based on two-dimensional cross-correlation within concentric cylindrical planes. The axial and angular displacement of the gaseous phase manifest themselves as the maximum position of the cross-correlation function.