Visualization and image processing for gas-liquid two-phase flow in a helical coil tube

In the steam generator of the fast breeder prototype reactor ''Monju'', heat exchange tubes of helical coil type are utilized. Steam-water two-phase flows in the helical coil tube have unique characteristic due to effects of centrifugal acceleration. In this report, we visualized gas-liquid two-phase flows in the helical coil tube for providing the flow pattern map, and suggested the method for reconstructing the interfacial structures of gas-liquid two-phase flows in the cross-section of the tube. The method was applied to artificial images and experimental images, and the applicability was discussed. (author)