Numerical simulation of fluid mixing phenomena in boiling water reactor with advanced interface tracking method

吉田 啓之; Zhang, W.; 三澤 丈治; 大貫 晃; 高瀬 和之

Proceedings of 3rd Asian-Pacific Congress on Computational Mechanics (APCOM '07) & 11th International Conference on Enhancement and Promotion of Computational Method in Engineering and Science (EPMESC-11) (CD-ROM), 10 Pages, 2007/12

Thermal-hydraulic design of the boiling water reactor (BWR) is performed by correlations with empirical results of actual-size tests. Development of a method that enables the thermal-hydraulic design of nuclear rectors without these actual size tests is desired, because these tests take a long time and entail great cost. For this reason we developed an advanced thermal-hydraulic design method for BWRs using innovative two-phase flow simulation technology. In this paper, the numerical results applied to the fluid mixing phenomena in the current boiling water reactor rod bundles and tight lattice rod bundles adopted in the innovative FLexible-fuel-cycle Water Reactor (FLWR) are shown and the existing correlations for the fluid mixing phenomena are evaluated by use of these results. And statistical evaluations of numerical simulation results are also performed to develop analytical method to confirm or modify the correlations for fluid mixing phenomena. In these statistical evaluations, attention was focused on instantaneous fluctuation characteristics of fluid mixing. With the calculation of correlation coefficients between the differential pressure and gas/liquid mixing coefficients, the time scales of fluid mixing were evaluated.