| 主权项 |
1. A method for providing cooling air from a source of cooling air through a cooling air circuit in a turbine section of a gas turbine engine, the method comprising:
providing a first portion of cooling air from the source of cooling air along a first path of the cooling air circuit to a plurality of blades associated with an upstream stage of the turbine section; providing a second portion of cooling air from the source of cooling air along a second path of the cooling air circuit, the second path including a turbine disc bore where the cooling air provides cooling to a radially innermost portion of at least one turbine disc that forms a part of a rotor of the engine, wherein the second path is independent from the first path such that the second portion of cooling air bypasses the upstream stage and is not mixed with the first portion of cooling air in the cooling air circuit after leaving the source of cooling air; and providing a third portion of cooling air from the source of cooling air along a third path of the cooling air circuit to a plurality of blades associated with an intermediate stage of the turbine section, the intermediate stage being downstream from the upstream stage with respect to a hot gas flowpath that is defined within the turbine section and that extends generally parallel to a longitudinal axis of the engine; wherein the third path is independent from the first and second paths such that the third portion of cooling air bypasses the upstream stage and is not mixed with the first or second portions of cooling air in the cooling air circuit after leaving the source of cooling air. |
