Two Phase Pressure Drop Multipliers and ICE Technique Applied in a Multibubble Slug Ejection Model

Abstract

Two-phase flow of coolant is described in subassemblies of liquid metal fast breeder reactors by a one-dimensional two-phase multibubble slug ejection model. Vapor flow of sodium between the slugs is modeled as annular flow with a moving liquid film of variable thickness wetting structural surfaces. The two-phase pressure drop multiplier concept introduced by Lockhart-Martinelli is used in the frame of the slug ejection model with an algorithm that simultaneously computes interfacial friction coefficient and liquid film axial velocity distribution. The implicit continuous Eulerian (ICE) technique developed by Harlow and Amsden for computing pressure distribution in a continuum medium is applied in heterogeneous two-phase flow to the governing equations for the vapor phase. This solution method is more stable than the numerical solution by finite differences of the vapor momentum equation.