A pressure based Eulerian-Eulerian multi-phase model for non-equilibrium condensation in transonic steam flow

A model for homogeneous nucleation in high-speed transonic flow and applicable to the wet stages of a steam turbine is presented. The model, implemented within a full Navier-Stokes viscous flow solution procedure, employs a pressure based finite-volume/finite-element discretization of the governing equations of fluid motion. Eulerian multiphase equations, governing both the vapor and liquid phases, are formulated utilizing Classical nucleation theory and the concept of droplet interfacial area density. For the mass conservation of liquid a scalar equation is derived which includes the dispersive motion of the droplets due to turbulent unsteadiness. The solution strategy applies implicit time integration with no constraints on the time-step. Convergence strategies with the highly non-linear homogeneous nucleation process are described. These equations are applied to predict the moisture distribution in low- and high-pressure steam flow in a Laval nozzle and 2D rotor-tip section of a stage turbine. (C) 2003 Elsevier Ltd. All rights reserved.