Visualization of gas-liquid interfacial behavior in a narrow channel using high-speed neutron imaging

Gas-liquid two-phase flow is a very complicated flow phenomenon that involves the interaction between gas and liquid phases. Recently, an accurate simulation technique of two-phase flow has been developed. However, the validation of the simulated results is insufficient due to less experimental data. It is especially difficult to measure interfacial behavior with significant spatio-temporal fluctuation. To understand such phenomena, measurement methods with high spatial and temporal resolutions are required. Neutron imaging is a powerful tool for two-phase flow visualization. It can be applied to flow measurement in an opaque channel and has applicability to the heated condition. In this study, two-phase flow in the narrow rectangular channel was visualized by high-speed neutron imaging. The dynamics of the interfacial structure of air-water flow were investigated from the neutron transmission images, and the liquid film behavior was observed qualitatively. (author)