| Abstract: | In this numerical investigation we simulate condensing flows typical for the last stages in low pressure steam turbines of large power plants. The main fluid dynamical characteristics are unsteadiness, high free stream turbulence, complex rotor/stator interaction and metastable conditions of the working fluid, leading to partial phase transition and polydispersed two‐phase flow in the transonic regime. Here we focus on a model for simulation of the condensation process which includes simultaneous homogeneous and heterogeneous nucleation. This model is applied to a turbine stage, consisting of one rotor and one stator. We found that the reduction of thermodynamic nonequilibrium by natural or artificial seeding with heterogeneous nuclei can reduce the thermodynamic losses, but after exceeding a certain limit the efficiency may be lower compared with pure homogeneous condensation. |
