Theoretical Study of Two-Phase Flow Oscillation in a Hot Channel, (I)

Theoretical Study for Interpreting the Mechanism of Hydrodynamic Instability

Abstract

Spontaneous two-phase flow oscillation, which can induce reactivity instability in BWR, is studied by numerical simulation, using a Fortran code. It is indicated that unstable flow is much more influenced by heat transfer characteristics than currently believed. In this study, particular attention is paid to such processes as energy storage, dissipation and transformation. Nonlinear flow oscillation of two-phase flow is dominantly governed by exchanges of heat between fluid and channel wall, which alternatively stores and releases the heat energy.