Detection of instantaneous phase changes in gas-liquid mixtures

Abstract

The paper presents a direct quantitative comparison of three phase detection systems for determination of local instantaneous phase changes in gas-liquid mixture flows. These include constant temperature heat transfer probes, various resistivity probes and an infrared absorption system. For each probe system estimates could be made of local void fractions, and these values indicated that the single needle resistivity probes caused least disturbance to the flow and were capable of resolving the smallest bubbles. With two such probes displaced axially, the mean transport time of the bubbles could be determined. These values were used to estimate local gas phase velocities which could be integrated to give average gas phase velocities. Values determined in this manner were compared to values from flow rate measurements and showed an average deviation of less than 6.2%.