Heat transfer enhancement of dynamoelectric machine rotors

A rotor is provided for a dynamoelectric machine having one or more windings. The windings have one or more turns, and the turns have one or more outlet ducts that are located near a chimney. When the outlet ducts are stacked one on top of another, they form substantially radially oriented passages. The heat transfer performance of a portion of the rotor can be improved by locating two or more circumferentially spaced radial ducts near the chimney. A chimney can also be formed of one or more chimney slots defined in at least a portion of the turns, where one or more chimney slots extend in a substantially slanted direction to a radial direction of the rotor. A transition region of the rotor can also include one or more diagonal flow channels, which discharge into one or more chimneys.