A New Wire-Mesh Tomograph for Gas-Liquid Flows

A wire-mesh tomograph for gas-liquid two-phase flows is presented. It is based on the measurement of the conductivity distribution over the cross section of the flow. Two planes of wire grids are placed into the flow in a short distance from each other. The angle between the wires of both grids is 90 °. The conductivity is measured at all cross points of the wires of the two planes. An imaging rate of 1000 frames per second was achieved, the measured data is directly transformed into local volumetric gas fractions without image reconstruction efforts. The minimal conductivity of the liquid necessary for applying the sensor is very low. Pure water (s » 0.5 µS/cm) can be measured without any problems. Up to now, the 2 x 16 wire mesh sensor was tested in a vertical air-water flow.