Gas turbine engine cooling systems having hub-bleed impellers and methods for the production thereof

A gas turbine engine cooling system comprising:

• an impeller, comprising:
• a hub;
• a plurality of impeller blades projecting from the hub;
• and
• a plurality of hub flow paths generally defined by an outer circumferential surface of the hub and the plurality of impeller blades;
• a central bleed air conduit having an inlet proximate the interior of the hub and having an outlet;
• a plurality of hub bleed air passages formed through an intermediate portion of the hub and fluidly coupling the hub flow paths to the central bleed air conduit, the plurality of hub bleed air passages conducting bleed air from the hub flow paths, through the hub, and to the central bleed air conduit to cool at least one component of the gas turbine engine during operation thereof;
• and
• a plurality of vortex spoiler tubes disposed within the hub and through which the plurality of hub bleed air passages extends.

A method for producing a gas turbine engine cooling system, comprising:

• assembling an impeller from an inducer piece and an exducer piece, the trailing radial face of the inducer piece residing adjacent the leading radial face of the exducer piece when the impeller is assembled;
• forming a plurality of hub bleed air passages in an intermediate portion of the impeller and extending from an outer circumferential surface of the impeller to an inner circumferential surface thereof;
• and
• disposing a plurality of vortex spoiler tubes within the impeller and through which the plurality of hub bleed air passages extends, the plurality of hub bleed air passages formed in at least one of the trialing radial face of the inducer piece and the leading radial face of the exducer piece prior to assembling the impeller.