Concomitancy of In-situ Concentration Measurements in Two-phase Flow in a Vertical Pipe

This experimental study deals with two-phase air-water flow generated in a vertical pipe measuring 35 mm in diameter. The complex nature of two-phase flow itself creates obstacles in detecting, monitoring and description of flow patterns, which are directly related to spatial and temporal distributions of concentration in the mixture. In addition to that, the difficulties in comparing results and noticed differences in reported results achieved in different experiments require more extensive research in this matter. Because of both high significance and difficulties in concentration measurements and existence of significant differences in the published results, one of the possible direction to close the gap and to more understand properties of the used methods is to conduct a comparative study of two most widely used measurement methods of concentration in terms of differences in the measured in-situ concentration for the same flow conditions (same time and space). This reported experimental study focuses on the comparison of two different concentration measurement methods (capacitive and conductive systems) including the determination of concomitancy for those two systems. In this experimentation a Computer Aided Experimentation System (CAES) is used to generate broad range of flow conditions and flow patterns in the vertical adiabatic flow, where the in-situ concentrations are measured simultaneously in the same time and space for air-water heterogeneous mixture flow. Based on the in-situ concentration measurements (full range of concentration) from both capacitive and conductive systems, the direct comparison between the results is presented and the concomitancy between the two systems is determined.