Development of Direct Steam-Water Phase Change Analysis Method Applying to BWR Operating Condition

Abstract

A simulation method applicable to estimation of the two-phase flow in Next Generation BWR fuel assembly has been developed. In this paper, to realize “design-by-analysis”, two CFD analysis models were developed. Firstly, the hybrid two-phase flow analysis model was developed to simulate the flow pattern transition. Using this model, it was confirmed that the generation of large bubbles by bubble coalescence could be simulated. Secondly, to analyze boiling phenomena, a phase-field model combined with Navier-Stokes equations was developed. We succeeded in simulating the boiling process, bubble nucleation, growth, and departure from heating wall directly under the BWR in-core pressure condition.