A PARAMETRIC STUDY OF THE AIR FLOW IN AN ELECTRIC GENERATOR THROUGH STEPWISE GEOMETRY MODIFICATIONS

Paper i proceeding, 2011

The air flow through an electric generator has been numerically investigated to give a better understanding of the flow for cooling purposes. A simple generator design has been chosen to start with, and stepwise modifications have been imposed to the design of the rotor and the stator. The flow properties for all cases have been compared to each other to investigate the effect of each parameter change on the flow inside the machine. The flow is predicted with the OpenFOAM solver MRFSimpleFOAM, which is a steady-state solver that uses the Frozen Rotor concept for the rotor-stator interaction. This means that there is no actual mesh movement in this study, but instead, the rotating regions in the domain are provided with source terms that account for rotation. The flow through the machine is not explicitly specified. Instead, it is the effect of the rotating regions that drive the flow through the machine. The reason for this is the lack of knowledge of the flow rate and inlet velocity distribution, which requires an approach without inlet and outlet. The flow is thus recirculating in the computational domain.