Comparative study of ultrafast X-ray tomography and wire-mesh sensors for vertical gas-liquid pipe flows

Wire-mesh sensors and ultrafast X-ray tomography were developed to investigate two-phase flows with high spatial and temporal resolution. In this study we present results of a comparative study for both imaging techniques, where disperse gas-phase velocity was available from both techniques for the first time. For the experiments we designed a special test section which was operated at HZDR's two-phase flow facility TOPFLOW. A very small vertical distance between X-ray planes and wire-mesh sensor guarantees that lateral flow changes during passage of the respective planes are almost negligible. Experiments were conducted with varying water and air superficial velocities, giving flow regimes from bubbly flow via slug flow to annular flow. Typical experimental results are presented and discussed in detail in this paper. Eventually, the application ranges for both measurement techniques are briefly discussed.