Presentation Information
[3E04]Development of Mechanistic Prediction Method of DNB Heat Flux Based on Two-Phase Flow CFD(8) Numerical analysis of vapor mass formation under forced convective boiling
*Ayako Ono1, Tomio Okawa2 (1. JAEA, 2. UEC)
Keywords:
Boiling,Bubble,Modeling,Large bubble formation,DNB,Forced convective boiling
We are developing a new prediction method for a departure from nucleate boiling (DNB) in the fuel assemblies, contributing to the design and safety evaluation for the new-generation reactors. In our project, we consider that the formation of a large vapor mass on the heating surface is the first trigger of the DNB. Therefore, we decided to predict the heat flux to form the large vapor mass by combining two-phase flow CFD and the large vapor mass formation model based on the mechanism. This method enables us to predict the DNB heat flux conservatively. In this study, we developed a simple numerical analysis method that simulates the generation, growth, motion, and coalescence of bubbles in order to predict the large bubble formation. We will report the basis of the models in the simple numerical analysis method and the results of the preliminary analysis.