2 PHASE PRESSURE-DROP MULTIPLIERS AND ICE TECHNIQUE APPLIED IN A MULTIBUBBLE SLUG EJECTION MODEL

Two-phase flow of coolant is described in subassemblies of liquid meta l fast breeder reactors by a one-dimensional two-phase multibubble slu g 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 in troduced by Lockhart-Martinelli is used in the frame of the slug eject ion model with an algorithm that simultaneously computes interfacial f riction coefficient and liquid film axial velocity distribution. The i mplicit continuous Eulerian (ICE) technique developed by Harlow and Am sden for computing pressure distribution in a continuum medium is appl ied in heterogeneous two-phase flow to the governing equations for the vapor phase. This solution method is more stable than the numerical s olution by finite differences of the vapor momentum equation.