Method and system for modulated turbine cooling

A method of cooling a turbine rotor, said method comprising:

• selectively channeling a first flow of cooling air through a manifold formed of bendable tubing, the manifold circumscribing a portion of the turbine rotor;
• channeling the first flow of cooling air to an inlet opening of a plurality of first inlet openings of an annular inducer through a feed tube extending axially aftward from the manifold to said inlet opening of the plurality of first inlet openings;
• accelerating the first flow of cooling air through a profiled passageway from said inlet opening of the plurality of first inlet openings to a slotted outlet opening, the slotted outlet opening extending approximately 45° of a circumference of an outlet face of the annular inducer;
• turning the first flow of cooling air in the profiled passageway from the inlet opening to the slotted outlet opening such that the first flow of cooling air exits the slotted outlet opening in a direction at least approximately 60° from a centerline of the profiled passageway at the slotted outlet opening;
• channeling a second flow of cooling air to at least one inlet opening of a plurality of second inlet openings of the annular inducer, the at least one inlet opening of the plurality of second inlet openings defining a teardrop shape on a curved surface of the annular inducer providing an efficient load path to stress induced in the annular inducer from a nozzle of a high pressure turbine of the gas turbine engine.

A turbofan engine comprising:

• a core engine including a multistage compressor;
• a fan powered by a power turbine driven by gas generated in said core engine;
• a fan bypass duct at least partially surrounding said core engine and said fan;
• and
• a modulated flow transfer system for transferring a fluid flow from said multistage compressor to a rotor of said core engine, said modulated flow transfer system comprising:
• a first fluid flow supply comprising a bleed connection from said multistage compressor, a feed manifold formed of bendable tubing, and a feed header extending between said bleed connection and said feed manifold, said feed header comprising a modulating valve configured to control an amount of first fluid flow from said bleed connection into said feed manifold;
• a flow supply tube extending axially aftward from said feed manifold;
• and
• an annular inducer configured to receive the first fluid flow from said first fluid flow supply through said flow supply tube, said annular inducer configured to accelerate the first fluid flow in a substantially circumferential direction in a direction of rotation of said rotor, said annular inducer comprising a row of a plurality of first and second fluid flow outlet openings extending circumferentially about said annular inducer, said annular inducer further comprising a row of a plurality of first and second fluid flow inlet openings extending circumferentially about said annular inducer, wherein at least one opening of said plurality of second fluid flow inlet openings comprises a teardrop shape on a curved surface of said annular inducer, said teardrop shape configured to present an efficient load path to stress induced in said annular inducer from a nozzle of a high pressure turbine of the gas turbine engine.