Patent attributes
A turbine assembly including a first rotor assembly with a rotatable outer drum from which one or more stages of a plurality of outer drum airfoils is extended radially inward is provided. An outer casing surrounds the outer drum of the first rotor assembly. A seal assembly is coupled to the outer casing and positioned radially outward from an upstream-most stage of the plurality of outer drum airfoils. The seal assembly is positioned in axial alignment with the upstream-most stage of the plurality of outer drum airfoils. The seal assembly separates a first plenum from a second plenum. The second plenum is formed axially aft of the first plenum and is formed by the seal assembly, the outer casing, and the outer drum of the first rotor assembly. The first plenum is positioned radially outward from the upstream-most stage of the plurality of outer drum airfoils.