Systems, methods, and apparatus for passive purge flow control in a turbine

A system for controlling radial temperature gradients in a rotor of a gas turbine, the system comprising:

• an air flow path to a bore of the rotor comprising a plurality of stacked wheels, wherein the path comprises at least one inlet hole on a rotor structure and a plurality of holes in the stacked wheels;
• and
• a sealing device for controlling air flow to the at least one inlet hole based at least in part on axial deflection between the rotor and an associated stator during operation of the gas turbine, wherein at least a portion of the air flow is directed to purge at least one wheel through the plurality of holes in the stacked wheels.

An apparatus for controlling radial temperature gradients in a rotor of a gas turbine, the apparatus comprising:

• an air flow path to a bore of the rotor comprising a plurality of stacked wheels, wherein the path comprises at least one inlet hole on a rotor structure and a plurality of holes in the stacked wheels;
• and
• a sealing device for controlling air flow to the at least one inlet hole based at least in part on axial deflection between the rotor and an associated stator during operation of the gas turbine, wherein at least a portion of the air flow is directed to purge at least one wheel through the plurality of holes in the stacked wheels.