Numerical estimation of losses in steam flow through LP turbine stages

The aim of this work is to estimate the losses in the steam flow through the LP steam turbine rotor and the whole stage. For steam flow two types of losses take place, aerodynamic (profile, secondary flow, leakage) and thermodynamic (due to the heat addition caused by condensation). Presented numerical results are split into two groups. In the first part of this work the comparison of the three different calculation methods of steam flow is carried out. To this end the geometry of LP steam turbine last rotor is chosen. The first method is a Streamline Curvature Method (SCM) used on the meridional plane with losses correlations, and the next two methods, commercial and an in-house CFD codes, solve the Reynolds averaged Navier-Stokes equations for a 3-D flow. Below the saturation line the first two codes model equilibrium steam properties, and the last one models non-equilibrium steam properties. Then for the geometry of the penultimate stage, with the use of an in-house CFD code, the comparison of the different types of condensation models on the losses prediction is examined.