EFFECTS OF END WINDING POROSITY UPON THE FLOW-FIELD AND VENTILATION LOSSES IN THE END REGION OF TEFC INDUCTION MACHINES

The authors describe the fundamental nature of the flow field and the influence of the end winding's porosity within the end region of a TEF C induction machine. A simulated end winding of simplified geometry wa s used for the investigation. Effects upon the flow field and ventilat ion losses are reported. Owing to the physical size and positioning of the end winding, changes in porosity produce large changes in flow ra te and circulation affecting the flow rates by varying the flow resist ance at the fan outlet and affecting the amount of flow through the en d winding itself, This affects all aspects of the flow field by alteri ng the angular momentum in the now circulation. The changes in flow ra te and circulation are also reflected by large changes in the ventilat ion losses.