Abstract: A gas turbine engine includes a shroud with an abradable section and a non-abradable section that cooperatively define a shroud surface. The gas turbine engine also includes a rotor that is supported for rotation within the shroud to generate an aft axial fluid flow. The rotor includes a blade with a blade tip that is crowned and that opposes the abradable section and the non-abradable section of the shroud surface. A crown area of the blade tip opposes the abradable section. A casing treatment feature is provided in the non-abradable section of the shroud to oppose the blade tip of the rotor.

Abstract: A compressor includes a rotor platform; a rotor blade; and a casing having an inner surface surrounding the tip and spaced radially outwardly from the tip to define a gap. A secondary air flow system includes a bleed inlet configured to remove secondary air flow from the primary air flow; an injection opening disposed in the inner surface of the casing upstream of the bleed inlet; an accessory conduit; and a plenum fluidly coupled to the bleed inlet, the injection opening, and the accessory conduit. The bleed inlet and plenum at least partially define a secondary air flow path such that a first portion of the secondary air flow is directed in through the bleed inlet, through the plenum, and out through the injection opening and a second portion of the secondary air flow is directed in through the bleed inlet, through the plenum, and out through the accessory conduit.

Abstract: A rotor includes a plurality of airfoils and each airfoil has a span that extends from 0% at a root to 100% at a tip, a chord that extends from 0% at a leading edge to 100% at a trailing edge and a pressure side opposite a suction side. The pressure side of each airfoil has a pressure side surface shape and the suction side of each airfoil has a suction side surface shape based on an operating state of the rotor. Each airfoil has the same suction side surface shape between 10% and 90% of the chord and between 80% and 100% of the span at a first state. At least one first airfoil has a different suction side surface shape between 10% and 90% of the chord and between 80% and 100% of the span than at least one second airfoil at a static state of the rotor.

Abstract: A gas turbine engine includes a shroud with an abradable section and a non-abradable section that cooperatively define a shroud surface. The gas turbine engine also includes a rotor that is supported for rotation within the shroud to generate an aft axial fluid flow. The rotor includes a blade with a blade tip that is crowned and that opposes the abradable section and the non-abradable section of the shroud surface. A crown area of the blade tip opposes the abradable section. A casing treatment feature is provided in the non-abradable section of the shroud to oppose the blade tip of the rotor.

Abstract: High performance wedge diffusers utilized within compression systems, such as centrifugal and mixed-flow compression systems employed within gas turbine engines, are provided. In embodiments, the wedge diffuser includes a diffuser flowbody and tapered diffuser vanes, which are contained in the diffuser flowbody and which partition or separate diffuser flow passages or channels extending through the flowbody. The diffuser flow channels include, in turn, flow channel inlets formed in an inner peripheral portion of the diffuser flowbody, flow channel outlets formed in an outer peripheral portion of the diffuser flowbody, and flow channel throats fluidly coupled between the flow channel inlets and the flow channel outlets. The diffuser vanes include a first plurality of vane sidewalls, which transition from linear sidewall geometries to non-linear sidewall geometries at locations between the flow channel inlets and the flow channel outlets.

Abstract: A rotor for a compressor includes a hub and a plurality of airfoils having a root, a tip opposite the root and a span that extends from 0% at the root to 100% at the tip. Each of the airfoils is coupled to the hub at the root and is spaced apart from adjacent ones of the airfoils over the span by a throat dimension. The throat dimension has a maximum value at a spanwise location between 60% of the span and 90% of the span of the adjacent ones of the airfoils, and at 10% of the span of the adjacent ones of the airfoils above or below the spanwise location of the maximum value, the throat dimension is less than 97% of the maximum value. The throat dimension at 5% of the span of the adjacent ones of the airfoils is less than 70% of the maximum value.

Abstract: Multistage gas turbine engine (GTE) compressors having optimized stall enhancement feature (SEF) configurations are provided, as are methods for the production thereof. The multistage GTE compressor includes a series of axial compressor stages each containing a rotor mounted to a shaft of a gas turbine engine. In one embodiment, the method includes the steps or processes of selecting a plurality of engine speeds distributed across an operational speed range of the gas turbine engine, identifying one or more stall limiting rotors at each of the selected engine speeds, establishing an SEF configuration in which SEFs are integrated into the multistage GTE compressor at selected locations corresponding to the stall limiting rotors, and producing the multistage GTE compressor in accordance with the optimized SEF configuration.

Abstract: A compressor section includes a shroud surface and a rotor with a blade tip that opposes the shroud surface. The rotor is configured to rotate within the shroud about an axis of rotation. Moreover, the compressor section includes a serration groove that is recessed into the shroud surface. The serration groove includes a forward portion with a forward transition and a forward surface that faces in the downstream direction. The forward transition is convexly contoured between the shroud surface and the forward surface. The serration groove includes a trailing portion with a taper surface and a trailing transition. The taper surface tapers inward as the taper surface extends from the forward surface to the trailing transition. The trailing transition is convexly contoured between the taper surface and the shroud surface.

Abstract: Multistage gas turbine engine (GTE) compressors having optimized stall enhancement feature (SEF) configurations are provided, as are methods for the production thereof. The multistage GTE compressor includes a series of axial compressor stages each containing a rotor mounted to a shaft of a gas turbine engine. In one embodiment, the method includes the steps or processes of selecting a plurality of engine speeds distributed across an operational speed range of the gas turbine engine, identifying one or more stall limiting rotors at each of the selected engine speeds, establishing an SEF configuration in which SEFs are integrated into the multistage GTE compressor at selected locations corresponding to the stall limiting rotors, and producing the multistage GTE compressor in accordance with the optimized SEF configuration.

Abstract: A method of manufacturing a multistage axial-centrifugal compressor for a gas turbine engine and a multistage axial-centrifugal compressor that includes a series of axial compressor stages each having a rotor mounted to a common shaft positioned upstream from a centrifugal compressor stage mounted to the common shaft. The method includes determining an operational rotor tip speed for each of the axial stages. The method includes comparing the operational rotor tip speed to a threshold range value and determining to machine an airfoil of the rotor for at least one of the axial stages by an arbitrary manufacturing approach based on the operational rotor tip speed as greater than the threshold range value. The method includes determining to machine an airfoil of the rotor for at least one of the axial stages by a flank manufacturing approach based on the operational rotor tip speed as less than the threshold range value.

Abstract: A propulsion and electric power generation system includes a gas turbine propulsion engine, an electrical generator, an aircraft power distribution system, a plurality of auxiliary fans, and a controller. The gas turbine propulsion engine includes at least a low-pressure turbine coupled to a fan via a low-pressure spool, and the low-pressure turbine is configured to generate mechanical power. The electrical generator is directly connected to the low-pressure spool and generates a total amount of electrical power (Pe). The aircraft power distribution system receives a first fraction (Pa) of the total amount of electrical power. The auxiliary fans receive a second fraction (Pf) of the total amount of electrical power. The controller is configured to control a ratio of Pf to Pa (Pf/Pa) such that the ratio spans a range from less than 0.6 to at least 0.9.

Abstract: Circumferentially-split diffuser assemblies utilized within compression systems, such as centrifugal and mixed-flow compression systems employed within gas turbine engines, are provided. In embodiments, the diffuser assembly includes flow passages, which extend through the diffuser assembly and which include diffuser flow passage sections. Diffuser airfoils are interspersed with the diffuser flow passage sections. The diffuser airfoils include inboard and outboard airfoil segments distributed around a diffuser assembly centerline. The inboard and outboard airfoil segments are contained in and, thus, defined by inner and outer annular diffuser structures, respectively. The outer annular diffuser structure circumscribes the inner annular diffuser structure.

Abstract: A system and method for determining particulate accumulation in a gas turbine engine includes sensing the number, size, and type of particulate at a first position on the gas turbine engine and supplying first data representative thereof, where the first position located at a first side of a gas turbine engine component; sensing the number, size, and type of particulate at a second position on the gas turbine engine and supplying first data representative thereof, where the second position located at a second side of the gas turbine engine component and downstream of the first position; and processing the first data and the second data to determine the mass of the particulate accumulated on the gas turbine engine component.

Abstract: A gas turbine engine includes a shroud with an abradable section and a non-abradable section that cooperatively define a shroud surface. The gas turbine engine also includes a rotor that is supported for rotation within the shroud to generate an aft axial fluid flow. The rotor includes a blade with a blade tip that is crowned and that opposes the abradable section and the non-abradable section of the shroud surface. A crown area of the blade tip opposes the abradable section. A casing treatment feature is provided in the non-abradable section of the shroud to oppose the blade tip of the rotor.

Abstract: A compressor for a turbine engine includes a shroud having a grooved section including a plurality of groove segments extending radially into a shroud surface. A rotor assembly rotatably supported in the shroud includes a rotor hub and a plurality of rotor blades. Each rotor blade extends radially from the rotor hub and terminates at a blade tip, which is spaced from the shroud surface by a tip gap and defines a non-constant clearance region between a leading edge position and a medial chord position along the blade chord at the minimum tip clearance. The rotor blades generate an aft axial fluid flow through the shroud and the grooved section is formed in the shroud surface upstream of the medial chord positon within the non-constant clearance region for resisting a reverse axial fluid flow through the tip gap when the compressor section is operated at near stall conditions.

Abstract: Embodiments of a core-protecting fan module are provided, as are embodiments of a turbofan engine containing such a fan module. In an embodiment, the core-protecting fan module contains a nose member, a fan rotor downstream of the nose member, a full span stator downstream of the fan rotor, and a splitter structure downstream of the fan rotor. The fan rotor includes a plurality of fan blades, which extends from a rotor hub and which is angularly spaced about a rotational axis. Certain fundamental angular relationships are observed between the angles formed by rotational axis, the nose member, the fan rotor, and a leading edge of the splitter structure to reduce contaminant ingestion by the core flow path and to promote moisture shedding to reduce susceptibility to icing within the fan module, while further avoiding or minimizing negative impacts to other structural and functional aspects of the turbofan engine.

Abstract: High performance wedge diffusers utilized within compression systems, such as centrifugal and mixed-flow compression systems employed within gas turbine engines, are provided. In embodiments, the wedge diffuser includes a diffuser flowbody and tapered diffuser vanes, which are contained in the diffuser flowbody and which partition or separate diffuser flow passages or channels extending through the flowbody. The diffuser flow channels include, in turn, flow channel inlets formed in an inner peripheral portion of the diffuser flowbody, flow channel outlets formed in an outer peripheral portion of the diffuser flowbody, and flow channel throats fluidly coupled between the flow channel inlets and the flow channel outlets. The diffuser vanes include a first plurality of vane sidewalls, which transition from linear sidewall geometries to non-linear sidewall geometries at locations between the flow channel inlets and the flow channel outlets.

Abstract: A rotor blade for a compressor of a gas turbine engine includes an airfoil extending from a root to a tip and having a leading edge and a trailing edge. The airfoil has a span that extends from 0% at the root to 100% at the tip and a mean camber line that extends from the leading edge to the trailing edge. The airfoil has a total camber distribution that increases from the root to a maximum value of total camber between 5% of the span and 20% of the span.

Abstract: A rotor blade for a compressor of a gas turbine engine includes an airfoil. The airfoil has a span that extends from 0% at the root to 100% at the tip and a mean camber line that extends from a leading edge to a trailing edge. The airfoil has a location of local maximum thickness defined as a ratio of a first arc distance along the mean camber line between the leading edge and a position of the local maximum thickness to a total arc distance along the mean camber line from the leading edge to the trailing edge. A value of the ratio increases from the root to a first position value, decreases from the first position value to a second position value and increases from the second position value to the tip. The first position value is at a spanwise location within 20% to 50% of the span.

Abstract: A rotor for a compressor includes a hub and a plurality of airfoils having a root, a tip opposite the root and a span that extends from 0% at the root to 100% at the tip. Each of the airfoils is coupled to the hub at the root and is spaced apart from adjacent ones of the airfoils over the span by a throat dimension. The throat dimension has a maximum value at a spanwise location between 60% of the span and 90% of the span of the adjacent ones of the airfoils, and at 10% of the span of the adjacent ones of the airfoils above or below the spanwise location of the maximum value, the throat dimension is less than 97% of the maximum value. The throat dimension at 5% of the span of the adjacent ones of the airfoils is less than 70% of the maximum value.