Numerical Modelling of Phase Distribution in Interconnected Subchannels

Abstract

The ASSERT subchannel code has been developed specifically to model flow and phase distributions within CANW fuel bundles. ASSERT uses a drift-flux model which permits the phases to have unequal velocities, and can thus model phase separation tendencies which may occur in horizontal flow. The basic principles of ASSERT are outlined, and computed results are compared against data from three air-water experiments in interconnected subchamels. The paper concludes with a discussion of the, use of the code to model boiling water vertical flow bundles and horizontal flow CANDU type geometries.