Flow Visualization on Gas-Liquid Two-Phase Flows in a Parallel 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 paper, we visualized gas-liquid two-phase flows in each the helical coil tubes with two curvature radii to investigate the effect of centrifugal acceleration, and also the slug flow in parallel helical coil tubes with same pressure condition at outlet part are visualized.