Abstract
Intermittent and heterogeneous behavior caused by interface motion is important for gas-liquid two-phase flow dynamics. Its complex characteristics are commonly treated with constitutive equations obtained from experimental database in the conventional two-fluid model. Numerical simulation by the extended two-fluid model, developed to calculate interface motion directly, can be an alternative tool to a part of experiments. Correlation of CCFL, counter current flow limiting, of upper tie plate is important for coolability assessment of BWR fuel assembly during LOCA conditions. Airwater CCFL experiments of a perforated thick plate were performed, and the falling water flow rates were measured as a function of upward air supply. Three-dimensional simulation of the experiments using the extended two-fluid model predicted the observed CCFL characteristics within data scatter. It is expected the simulations by the extended two-fluid model is useful to actual tie plate design of future reactor fuels.
