Abstract: A system for delivering a flow stream of a gas to a compressor. A shroud extends from an inlet to the compressor and defines a main inlet passage configured to direct the flow stream from the inlet to the compressor. A communication plenum is separated from the main inlet passage. A port system includes first and second port subsystems that each provide an opening between the main inlet passage and the communication plenum. The first port subsystem is disposed further from the compressor than the second port subsystem. The port system is configured so that a portion of the gas enters or exits the compressor through the second port subsystem, depending on operating conditions of the compressor.

Abstract: A turboprop engine system for an aircraft includes an engine, a propeller, and a gear train coupled to and configured to provide power from the engine to the propeller at a predetermined gear reduction. The engine system also includes a gearbox that houses at least part of the gear train. The gearbox includes a gearbox flow structure and an inlet flow structure that is removably attached to the gearbox. The inlet flow structure and the gearbox flow structure cooperate to define an inlet flow passage to the engine. The inlet flow passage has an upstream end and a downstream end that are cooperatively defined by the inlet flow structure and the gearbox flow structure. The upstream end is configured to receive an airstream that is directed along the inlet flow passage to the downstream end and toward the engine.

Abstract: A turboprop engine system for an aircraft includes an engine, a propeller, and a gear train coupled to and configured to provide power from the engine to the propeller at a predetermined gear reduction. The engine system also includes a gearbox that houses at least part of the gear train. The gearbox includes a gearbox flow structure and an inlet flow structure that is removably attached to the gearbox. The inlet flow structure and the gearbox flow structure cooperate to define an inlet flow passage to the engine. The inlet flow passage has an upstream end and a downstream end that are cooperatively defined by the inlet flow structure and the gearbox flow structure. The upstream end is configured to receive an airstream that is directed along the inlet flow passage to the downstream end and toward the engine.

Abstract: A system for delivering a flow stream of a gas to a compressor. A shroud extends from an inlet to the compressor and defines a main inlet passage configured to direct the flow stream from the inlet to the compressor. A communication plenum is separated from the main inlet passage. A port system includes first and second port subsystems that each provide an opening between the main inlet passage and the communication plenum. The first port subsystem is disposed further from the compressor than the second port subsystem. The port system is configured so that a portion of the gas enters or exits the compressor through the second port subsystem, depending on operating conditions of the compressor.

Abstract: High temperature rolling element bearings and methods for manufacturing high temperature bearing components, such as bearing races or rings, are provided. In one embodiment, the method includes obtaining a powder mixture containing a superalloy powder admixed with hard wear particles, such as carbide particles. The powder mixture is consolidated utilizing a spark plasma sintering process during which the powder mixture is compressed into a sintered blank, while an electrical current is conducted through the powder mixture to heat the powder mixture to a sintering temperature. The sintered blank is then machined to impart the bearing component with its final shape. Precipitate hardening may also be performed, if desired. The spark plasma sintering process is controlled to limit the temperature and duration of the powder consolidation process thereby imparting the resulting bearing component with an enhanced hot hardness and other desirable properties at highly elevated operating temperatures.

Abstract: High temperature rolling element bearings and methods for manufacturing high temperature bearing components, such as bearing races or rings, are provided. In one embodiment, the method includes obtaining a powder mixture containing a superalloy powder admixed with hard wear particles, such as carbide particles. The powder mixture is consolidated utilizing a spark plasma sintering process during which the powder mixture is compressed into a sintered blank, while an electrical current is conducted through the powder mixture to heat the powder mixture to a sintering temperature. The sintered blank is then machined to impart the bearing component with its final shape. Precipitate hardening may also be performed, if desired. The spark plasma sintering process is controlled to limit the temperature and duration of the powder consolidation process thereby imparting the resulting bearing component with an enhanced hot hardness and other desirable properties at highly elevated operating temperatures.

Abstract: A method for manufacturing a valve assembly includes the steps of: providing one or more nickel-based superalloy components of the valve assembly, wherein the one or more components are designed to be subjected to operating environments including temperatures of about 760° C., +/?about 30° C.; aluminizing the one or more components using an aluminizing process, wherein the aluminizing process causes inter-diffusion between the nickel-based superalloy and aluminum as well as forms an aluminum-rich surface layer on the one or more components, thereby forming one or more aluminized components; and subjecting the one or more aluminized components to a plasma electrolytic oxidation process to convert the aluminum rich surface layer into a hard, wear-resistant, and oxidation-resistant aluminum oxide coating layer, wherein the hardness, wear-resistance, and oxidation-resistance of the aluminum oxide coating layer is maintained in the operating environments including temperatures of about 760° C., +/?about 30° C.

Abstract: Methods of forming dual microstructure components include consolidating a powder material comprising an alloy to form a billet, the billet having a first grain structure, inductively heating the billet at an inductive heat treat temperature above a gamma prime solvus temperature of the alloy and subjecting the billet to a subsolvus heat treat temperature that is below the gamma prime solvus temperature of the alloy, waiting a period of time for the first grain structure in an outer portion of the billet to transform into a second grain structure that is coarser than the first grain structure, after the steps of inductively heating and subjecting the billet to the subsolvus heat treat temperature. The methods also include dividing the billet into at least two sections, and machining a final shape into one or more of the at least two sections to form the dual microstructure component.

Abstract: There is provided a method for fabricating a dual alloy structure that may in turn be machined to fabricate a rotary component for use in a gas turbine engine. The method provides a powder metal (PM) nickel based superalloy and a nickel aluminide intermetallic based alloy. The powder metal (PM) nickel based superalloy displays characteristics, such as improved strength, low cycle fatigue resistance, fracture toughness, and crack growth resistance. The nickel aluminide intermetallic based alloy displays characteristics, such as high temperature creep and oxidation resistance, suitable for use in the outer radial area of an impeller. A bore sub-element is fabricated from the powder metal (PM) nickel based superalloy. A body sub-element is fabricated from the nickel aluminide intermetallic based alloy. The bore sub-element and body sub-element are joined by inertia welding or diffusion bonding at a common mating surface.

Abstract: Methods of forming dual microstructure components include consolidating a powder material comprising an alloy to form a billet, the billet having a first grain structure, inductively heating the billet at an inductive heat treat temperature above a gamma prime solvus temperature of the alloy and subjecting the billet to a subsolvus heat treat temperature that is below the gamma prime solvus temperature of the alloy, waiting a period of time for the first grain structure in an outer portion of the billet to transform into a second grain structure that is coarser than the first grain structure, after the steps of inductively heating and subjecting the billet to the subsolvus heat treat temperature. The methods also include dividing the billet into at least two sections, and machining a final shape into one or more of the at least two sections to form the dual microstructure component.

Abstract: There is provided a method for fabricating a dual microstructure component that may in turn be machined to fabricate a rotary element such as an impeller characterized as capable of withstanding high heat conditions for use in a gas turbine engine. The method provides a nickel based superalloy suitable for application of an impeller in a gas turbine engine. The bore region is manufactured having a grain size finer than ASTM 10.0 and the body region is manufactured having a grain size coarser than ASTM 7.0. The bore region and the body region define a dual microstructure and an interface.

Abstract: There is provided a method for fabricating a dual alloy structure that may in turn be machined to fabricate a rotary component for use in a gas turbine engine. The method provides a powder metal (PM) nickel based superalloy and a nickel aluminide intermetallic based alloy. The powder metal (PM) nickel based superalloy displays characteristics, such as improved strength, low cycle fatigue resistance, fracture toughness, and crack growth resistance. The nickel aluminide intermetallic based alloy displays characteristics, such as high temperature creep and oxidation resistance, suitable for use in the outer radial area of an impeller. A bore sub-element is fabricated from the powder metal (PM) nickel based superalloy. A body sub-element is fabricated from the nickel aluminide intermetallic based alloy. The bore sub-element and body sub-element are joined by inertia welding or diffusion bonding at a common mating surface.