Development of Drift Flux-Type Correlations Considering Bubble Induced Turbulence in Vertical Gas-Liquid Metal Two-Phase Flow

Abstract

In hypothetical steam generator tube rupture (SGTR) accident scenario of pool-type liquid metal cooled fast breeder reactor, water is injected from SG into primary circuit through the break and flash. The injected steam bubbles may transport into the core region and insert positive reactivity, which threaten the reactor safety. To accurately predict the void fraction for evaluation of accident consequence, drift flux model applied to gas-liquid metal two-phase flow is useful and need to be developed. In this contribution, an algebraic model aimed at bubble induced turbulence (BIT) is introduced to improve the underestimation of turbulent viscosity calculated by Clark’s force balance model to accurately predict the one-dimensional liquid velocity distribution along radial direction in flow channel. On this basis, the distribution parameter is calculated. Analysis result shows that distribution parameter is assuming very high values at low Re number. With Froude number increase, distribution parameter tends to decrease. At lower void factions, distribution parameter is also assumed to be high values. It indicates that the pipe size, flow rate and void fraction can all influence distribution parameter. Considering the quantitative laws of above influence factors obtained by theoretical analysis and fitting test data, a new correlation for gas-liquid metal two-phase flow is developed and evaluated.