Abstract: A shrouded impeller includes an impeller having a plurality of blades and configured to rotate about an axis, and a shroud disposed adjacent to the impeller and configured to corotate about the axis with the impeller and translate axially relative to the impeller. A method of varying a geometry of a flow area of the shrouded impeller includes rotating the shroud and the impeller about the axis and axially translating the shroud relative to the impeller to increase or decrease a rate of flow between the shroud and the impeller.

Abstract: A shrouded impeller includes an impeller having a plurality of blades and configured to rotate about an axis, and a shroud disposed adjacent to the impeller and configured to corotate about the axis with the impeller and translate axially relative to the impeller. A method of varying a geometry of a flow area of the shrouded impeller includes rotating the shroud and the impeller about the axis and axially translating the shroud relative to the impeller to increase or decrease a rate of flow between the shroud and the impeller.

Abstract: A propulsion system for an aircraft includes a core engine that includes a core flow path that is in communication with a compressor section, combustor section and a turbine section, the core engine is configured to generate a high energy gas flow, a first cycle turbine that is configured to drive a first cycle compressor at a cycle speed in response to expansion of a heated working fluid flow between a first inlet and a first outlet of the first cycle turbine, and a first power turbine that is configured to drive a first output shaft at a power speed that is different than the cycle speed in response to expansion of a working fluid flow received from the first outlet of the first cycle turbine.