Assessment of Two Phase Turbulent Mixing Models for Subchannel Analysis Relevant to BWR

Abstract

Determination of turbulent mixing rate of two phase flow between neighboring subchannels is an important aspect of subchannel analysis in reactor rod bundles. Various models have been developed for two phase turbulent mixing rate between subchannels. These models show that turbulent mixing rate is strongly dependent on flow regimes; their validity was examined against specific or limited experiments. It is vital to evaluate these models by comparing the predicted two phase turbulent mixing rate with available experimental data conducted for various subchannel geometries and operating conditions. This paper describes evaluation of different models for two phase turbulent mixing rate for both gas and liquid phase against large range of experimental data which are obtained from various subchannel geometries. The results indicate that there is large discrepancy between the predicted and experimental data for turbulent mixing rate.

Keywords: Subchannel analysis, two phase turbulent mixing model, turbulent mixing rate