Thermal Performance Prediction in the Air Gap of a Rotor-Stator Configuration: Effects of Numerical Models

Abstract

This study is dedicated to a numerical investigation of convective heat transfer on the rotor surfaces of a rotor-stator configuration that is typically found in large hydro-generators. The computational fluid dynamics calculations with two turbulence modelling approaches are used to predict the flow structure and heat transfer in the air gap of the rotor-stator configuration. The steady state mixing plane approach is employed at the interface to couple the rotor and stator components. Results show that the location of mixing plane interface in the air gap plays an important role in the prediction of heat transfer on the pole face. Also, it is indicated that the prediction of temperature distribution on the pole face is greatly affected by the turbulence models used. Furthermore, through a comparison between the pure convective and conjugate heat transfer methodologies, it is shown that the inclusion of solid domain into the numerical model significantly improves the thermal prediction of the solid components of the machine.