Measurements of liquid-metal two-phase flow by using neutron radiography and electrical conductivity probe

Neutron radiography and electrical four-sensor conductivity probe method were applied to measurement of liquid-metal two-phase flow. Visualization and measurements of nitrogen gas-molten lead bismuth two-phase flow were performed by using neutron radiography technique. Simultaneous measurements of void fraction by using high-frame-rate neutron radiography and four-sensor probe were also performed to observe the bubble-probe interaction. At the same experimental conditions, four-sensor probe was applied to the measurements of interfacial area concentration in radial direction. From the visualization of the two-phase flow, it turned out that cap bubbles or elongated slug bubbles were dominant at the superficial gas velocity of 1.1-38.3 cm/s and no stable Taylor bubbles were detected in this experiment. Measured radial void fraction profiles obtained by neutron radiography and electrical conductivity probe agreed well with each other. From these measurements, the measurement error and basic characteristics of gas-liquid-metal two-phase flow were clarified.