Experimental dataset with high-speed visualization for vertical upward steam-water flow with transition from annulus to circular channel

A new database for steam-water flow is developed by the Multiphase Thermo-fluid Dynamics Laboratory (MTDL) at the University of Illinois at Urbana-Champaign. The experiment is carried out in a test section spanning the transition from an annulus to pipe, with one of the goals to study the effects of flow-geometry change on two-phase transport. Four-sensor conductivity probes are used to measure local two-phase parameters such as void fraction, interfacial area concentration, Sauter mean diameter, and gas velocity at 11 radial locations across the flow channel and five axial locations along the flow channel. The radial and axial profiles for selected conditions are presented and their features are discussed extensively. Parametric study is also carried out to understand the impact of flow parameters on steam-water flows under flashing condition. Besides, glass viewports are installed at three axial locations in the test section to observe the flow structure especially at the point of transition between the annulus and the pipe. The dataset, along with the high-speed videos, are valuable for the validation of the modeling and simulation of steam-water flows.