Prediction of the equilibrium two-phase flow distributions in inter-connected subchannel systems

This paper discusses the hydrodynamic equilibrium two-phase flow distributi on phenomena in unheated subchannel systems. A set of two-fluid governing e quations is solved and the solutions are compared with the equilibrium air- water two-phase flow experimental data from an inter-connected two-subchann el test section in the slug to chum-turbulent flow regime. It is shown that the two-phase flow under the hydrodynamic equilibrium condition is distrib uted to make the minimum of possible pressure gradients. It is also shown t hat this minimum pressure gradient is closely related to the minimum energy dissipation of the total flow system. Finally a model is proposed to predi ct the hydrodynamic equilibrium two-phase flow distribution in a rod bundle as a minimization problem of the energy dissipation with mass continuity a nd momentum balance equations as the constraints.