Abstract: A gas turbine engine includes a fan drive turbine driving a fan rotor through a main gear reduction. A primary lubricant system supplies lubricant to the main gear reduction. An auxiliary oil pump supplies oil to the main gear reduction. An auxiliary pump epicyclic gear train drives the auxiliary pump when the fan rotor is rotating in either direction. The main gear reduction is separate from the auxiliary pump epicyclic gear train.

Abstract: A bearing compartment of a gas turbine engine includes a rotationally fixed structure defined about an engine longitudinal axis; a gutter section formed in the front support; an oil drainback assembly mountable to the gutter section to direct oil into a drain passage to communicate oil from the gutter.

Abstract: A combustor assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a combustion chamber, and a fuel injector assembly in communication with the combustion chamber that has a swirler body situated about a nozzle to define an injector passage that converges to a throat. The throat is defined at a distance from the combustion chamber. The nozzle includes a primary fuel injector and an array of secondary plain jet fuel injectors.

Abstract: A gas turbine engine includes a fan section that includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor includes a greater number of stages than the low pressure turbine. A high spool includes a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine stage high pressure compressor and includes a pressure ratio per stage of greater than or equal to 1.20 and less than or equal to 1.33.

Abstract: A gas turbine engine has a compressor section and a turbine section. A secondary cooling air includes a first fluid connection to tap cooling air and pass the cooling air through a plurality of tubes, and a second fluid connection for returning air from the tubes back to at least one of the compressor and turbine for cooling. A sensor senses a condition of the cooling air downstream of the tubes and a control compares the sensed condition of the cooling air to an expected condition, and to identify a potential concern in the cooling air system should the sensed condition differ from the expected condition by more than a predetermined amount.

Abstract: A gas turbine engine includes an engine case along an engine axis, a conformal accessory drive gearbox housing mounted to the engine case, and at least one accessory mounted to the conformal housing.

Abstract: A vane system includes a plurality of vane assemblies and a continuous support ring. The vane assemblies are arranged circumferentially about an axis and each include a hollow airfoil fairing and a spar. The spar has a spar flange and a spar leg extending radially inwardly from the spar flange and through the hollow airfoil fairing. The continuous support ring has radially inner and outer sides and defines a circumferential row of through-holes between the radially inner and outer sides. The spar legs extend through the through-holes and the spar flanges are affixed at the radially outer side of the continuous support ring.

Abstract: A seal assembly for a gas turbine engine, having a seal formed of a carbon material; and a seal seat positioned for rotation relative to the seal, wherein the seal and the seal seat each have a sealing surface which together define a sliding seal, and wherein at least the sealing surface of the seal seat is made of the same carbon material as the sealing surface of the seal.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a propulsor section, a geared architecture, a high spool and a low spool. The high spool includes a high pressure compressor and a high pressure turbine. The low spool includes a low pressure compressor and a low pressure turbine. At least one stage of the turbine section includes an array of rotatable blades and an array of vanes. A ratio of the number of vanes to the number blades is greater than or equal to 1.55. A mechanical tip rotational Mach number of the blades is greater than or equal to 0.5 at an approach speed.

Abstract: A cooling system for a plurality of conductive cables in a gas turbine engine includes a cooling source and an electric motor disposed in a tail cone. The cooling source may comprise an electric fan or an oil pump. The cooling source may be configured for active cooling of the plurality of conductive cables. The electric fan may be in fluid communication with ambient air during operation of the gas turbine engine.

Abstract: A method of coating a component including aluminizing an array of internal passageways within the component; and chromizing a portion of the array of internal passageways within the component. A component, including an airfoil having an array of aluminized internal passageways, the array of aluminized internal passageways chromized up to a demarcation.

Abstract: Feed rate scheduling methods include measuring a topography of a grinding wheel of a machine tool, calculating a topography parameter using the topography, and calculating a feed rate scheduling parameter for a toolpath of the grinding wheel based on the topography parameter. The topography may be measured using microscopy. The topography parameter may include a plurality of parameters including a density of crystals at a given depth (C(h)) of the grinding wheel and/or an area fraction of crystals protruding at a given depth (?(h)) of the grinding wheel. The feed rate scheduling parameter may include a grinding wheel feed rate, a grinding wheel spin rate, and/or a grinding wheel cutting depth, among other parameters.

Abstract: Systems and methods for mesh refinement of finite element analysis simulations employ an analytical modeling program configured to identify a location of contact between two components and a finite element analysis program configured to use the identified location to perform finite element mesh refinement. In this regard, the location of contact (and location of desired mesh refinement) is identified using analytical modeling. Said location of contact is then provided to the finite element analysis program for determining precisely where to perform mesh refinement on the finite element mesh. The finite element analysis program performs a mesh refinement at the exact location of contact between two components to provide for optimized and more efficient finite element analysis.

Abstract: A feed rate scheduling method may comprise: receiving an engagement geometry of a subtractive component for use in a computer numerical control (CNC) machining process; receiving a tool path for forming a component from a workpiece via the CNC machining process; calculating a plurality of bending moments of a spindle at various intervals along the tool path; and determining a feed rate schedule for the tool path of the subtractive component based on the plurality of bending moment.

Abstract: A blade fabrication method is provided and includes additively manufacturing a core, securing the core to a mandrel, electroforming a leading edge sheath directly onto the core and the mandrel and removing the mandrel from the core and the leading edge sheath.

Abstract: A gas turbine engine includes a fan that has fan blades wherein the fan delivers airflow to a bypass duct. A gearbox is defined along an engine axis. A low spool is arranged aft of the gearbox and coupled to drive the gearbox. A front center body assembly is defined around the engine axis. A flexible support supports the gearbox relative to the front center body assembly. A bearing package is mounted to the front center body assembly and the low spool. A front wall is mounted to the front center body assembly. The front wall is removable from the front center body assembly to access at least one of the gearbox or the bearing package. The low spool includes a low pressure compressor hub that provides a spline for engaging the bearing package.

Abstract: An optical probe includes an optical housing, a transmitting lens and a receiving lens. The optical housing extends from a proximate end to an opposing distal end. The transmitting lens is disposed at the distal end and is configured to output a first transmitted signal beams having a first transmission axis and a second transmitted beam having a second transmission axis that is different from the first transmission axis. The receiving lens is disposed at the distal end and configured to receive the first and second reflected signal beams corresponding respectively to the first and second transmitted signal beams. The optical housing has formed therein a transmitting optical channel configured to communicate an input optical signal from the proximate end to the transmitting lens. A receiving optical channel separated from the transmitting optical channel communicates the first and second reflected signal beams to the proximate end.

Abstract: A gas turbine engine includes a turbine section that has a plurality of turbine vanes. Each of the turbine vanes includes inner and outer platforms and an airfoil section that extends there between. The airfoil section is hollow and rib-less and has a first end at the outer platform and a second end at the inner platform. The airfoil section is tangentially bowed from the first end to the second end with a radius of curvature that is from 17 centimeters to 130 centimeters.

Abstract: A method of repairing a tip of an airfoil can comprise: removing a coating from the tip of the airfoil; preparing a repair area for bonding, the repair area including the tip and a portion of a concave side of the airfoil; applying an epoxy film and an abrasive component to the repair area; and bonding the epoxy film and the abrasive component to the repair area.

Abstract: A seal segment has an arcuate body having: a first end; a second end circumferentially opposite the first end; a first face; a second face axially opposite the first face; an inner diameter (ID) face; and an outer diameter (OD) face. The seal segment is shaped to interfit with a plurality of identical seal segments first end to second end to form a seal surrounding a central longitudinal axis. The first face has: a circumferential channel closer to the ID face than the OD face; and a plurality of channels extending from the circumferential channel to the OD face. The ID face has: a circumferential channel closer to the first face than the second face; and a plurality of channels extending from the circumferential channel to the second face. The ID face circumferential channel has an open end.