Electrical impedance string probes for two-phase void and velocity measurements

• Published in: International journal of multiphase flow Vol. 10; no. 5; pp. 541 - 556
• Main Authors: Hardy, J.E., Hylton, J.O.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1984; Elsevier
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Instrumentation for fluid dynamics; Metering, regulation, automation in energy; Physics; Theoretical studies. Data and constants. Metering; Water; Two phase flow; Flow(fluid); Measuring system; Monographs; Void fraction; Air; Experimental study; Performance; Water vapor; Velocity
• ISSN: 0301-9322; 1879-3533
• DOI: 10.1016/0301-9322(84)90080-6

An instrumentation system was developed to measure two-phase flow velocity and void fraction. The principle of operation of this system was based on the measurement of the electrical impedance of two-phase mixtures. Two-phase velocity is estimated by time-of-flight analysis of signals from two spatially separated sensors. A technique involving measurement of both the capacitance and the conductance of the mixture was used to determine void fraction and correct for the effect of liquid distribution. The string probe instrumentation proved to be durable in air/water and steam/water flows and demonstrated an ability to measure a wide range of flow velocities (1–17 m/s) and void fractions (0.25−0.99+).