Rotor cooling structures

A rotor defines an axial direction and a radial direction relative to an axis of rotation and includes an annular hub and a core disposed radially outward of the annular hub. The core defines a first axial side and a second axial side. First radial feed holes are formed in the annular hub, and are located between the first and second axial sides. Axial channels are formed between the core and the annular hub, and are in fluid communication with the first radial feed holes and span substantially between the first and second axial sides. The rotor also includes a first member and a second member, adjacent to the first and second axial sides, respectively. First and second apertures are formed in the first and second members, respectively. Each of the first and second apertures is in fluid communication with one of the axial channels.