Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, a fan, a compressor section, a turbine section including a fan drive turbine and a second turbine, an epicyclic gear system with a gear reduction, first and second bearings, and a fan drive shaft interconnecting the gear system and the fan. The fan drive turbine has a first exit area at a first exit point and is rotatable at a first speed. The second turbine has a second exit area at a second exit point and is rotatable at a second speed. A first performance quantity is defined as the product of the first speed squared and the first area. A second performance quantity is defined as the product of the second speed squared and the second area.

Abstract: An airfoil for a gas turbine engine according to an example of the present disclosure includes a platform section and an airfoil section extending in a spanwise direction from the platform section to a tip portion establishing a tip. The airfoil section has an external wall defining pressure and suction sides extending in a chordwise direction between a leading edge and a trailing edge, and the pressure and suction sides are spaced apart in a thickness direction between the leading edge and the trailing edge. The tip portion includes a tip pocket and a tip shelf extending inwardly from the tip. The tip pocket and tip shelf are on opposite sides of a shelf wall.

Abstract: A wireless sensor system of a gas turbine engine of an aircraft can include a plurality of wireless sensors distributed within an engine core of the gas turbine engine and an energy harvesting system including one or more energy harvesting devices configured to convert mechanical or thermal energy within the gas turbine engine into electric power and provide the electric power to the wireless sensors. The wireless sensor system can also include a data concentrator coupled to the gas turbine engine. The data concentrator can be configured to receive a plurality of wireless sensor data from the wireless sensors and transmit the wireless sensor data to a communication adapter of the gas turbine engine.

Abstract: A replaceable rotor blade tip clearance measurement device for a gas turbine engine, includes a threaded section along an axis and an integral abradable tip with an internal lattice geometry that extends from the threaded section along the axis.

Abstract: Propulsion systems for aircraft include a fan and a low pressure turbine operably coupled to a first shaft, a low pressure compressor and an intermediate pressure turbine operably coupled to a second shaft, and a high pressure compressor and a high pressure turbine operably coupled to a third shaft. A burner is arranged between the high pressure compressor and the high pressure turbine, with a main flow path defined through the propulsion system. A hydrogen fuel system is configured to supply hydrogen fuel to the burner. A condenser is arranged along the main flow path and configured to extract water from exhaust from the burner. An evaporator is arranged along the main flow path and configured to receive a portion of the water to generate steam which is injected into the main flow path upstream from the evaporator.

Abstract: An aircraft propulsion system includes a gas turbine engine; an environmental control system (ECS); and a bleed flowpath from the gas turbine engine through the ECS. A turbine is along the bleed flowpath and a propulsion fan is mechanically coupled to the turbine to be driven by the turbine.

Abstract: A manufacturing method is provided during which a preform component for a turbine engine is provided. The preform component includes a substrate and a locating feature at an exterior surface of the substrate. An outer coating is applied over the substrate. The outer coating covers the locating feature. At least a portion of the preform component and the outer coating are scanned with an imaging system to provide scan data indicative of a location of the locating feature. A cooling aperture is formed in the substrate and the outer coating based on the scan data.

Abstract: A heat exchanger for heat transfer between an external first flow along a first flowpath and a second flow along an internal second flowpath, has: a first manifold; a second manifold; and a plurality of tubes extending from the first manifold to the second manifold and having respective interiors bounding respective legs of the second flowpath. The plurality of tubes comprises a plurality groups of tubes. For each of the groups of the tubes: the tubes of the group have first ends mounted to the first manifold at respective first locations; and the tubes of the group have second ends mounted to the second manifold at respective second locations. From the first manifold to the second manifold, each tube has: a upstream concave first turn; an upstream convex second turn; and an upstream concave third turn; and the second locations are offset downstream along the first flowpath from the respective first locations.

Abstract: An airfoil vane includes an airfoil section which includes an outer wall that defines an internal cavity. A baffle is situated in the internal cavity. The baffle includes a leading edge portion and a trailing edge portion which is bonded to the leading edge portion at a joint. The leading edge portion and the trailing edge portion define an internal cavity therewithin. Both the leading edge portion and the trailing edge portion include a plurality of cooling holes which are configured to provide cooling air to the airfoil outer wall. The trailing edge portion is formed of sheet metal and the leading edge portion is formed of non-sheet-metal. A method of making a baffle for a vane arc segment and a method of assembling a ceramic matrix composite airfoil vane are also disclosed.

Abstract: A method of forming a ceramic matrix composite airfoil includes forming a fibrous ceramic preform by laying up a plurality of plies to form a hollow core cavity, overwrapping the plurality of plies of the core cavity with a first overwrap layer, weaving together a tows of first free portion and tows of a second free portion of the first overwrap layer to form a cross brace, overwrapping the plurality of plies of the core cavity and the first overwrap layer with a second overwrap layer, and consolidating the first free portion and the second free portion of the first overwrap layer and a third free portion and a fourth free portion of the second overwrap layer to form a trailing edge.

Abstract: A process for additively controlled surface features of a gas turbine engine casing. The process comprises forming the casing having an inner surface and an outer surface opposite the inner surface; forming a surface feature on the casing proximate the inner surface, wherein the surface feature comprises a structure on the inner surface configured to align or misalign with respect to a flow direction of a working fluid in a flow path of the casing.

Abstract: An engine control system includes an engine controller configured to execute an open-loop model of the engine control system. The open-loop model receives a measured effector and boundary condition parameter vector and generates a synthesized engine operating parameter based on the measured effector and boundary condition parameter vector. The engine controller calculates a corrector error value between the synthesized engine operating parameter and a measured engine operating parameter, and determines an open loop corrector error calculated as a difference between the corrector error and a vector-matrix product of corrector state vector and a gain map/function. The engine controller applies the gain map/function to the open loop corrector error to determine an effector and boundary condition error vector of the measured effector and boundary condition parameter vector.

Abstract: A thermal barrier coating is provided. The thermal barrier coating is configured to remain adherent to a substrate under high strains, thus allowing the use of non-contacting strain measurement systems, using digital image correlation for example. The thermal barrier coating may include a first layer of a partially metallic material configured to adhere to a metallic substrate, and a second layer of a partially ceramic material configured to adhere to the first layer. A successful configuration has a top layer thickness that is approximately two-thirds of the first layer thickness.

Abstract: Airfoils and core assemblies for such airfoils are described. The airfoils include a leading edge cavity defined, in part, by a leading edge interior rib and a trailing edge cavity defined, in part, by a trailing edge interior rib. A plurality of pressure side cavities are defined by pressure side skin cavity walls with at least one pressure side skin cavity wall not extending to the suction side wall. A plurality of suction side cavities are defined by suction side skin cavity walls with at least one suction side skin cavity wall not extending to the pressure side wall. A main body cavity extends between the leading edge interior rib and the trailing edge interior rib and the plurality of side cavities are arranged in a staggered pattern to define the bounds of the main body cavity.

Abstract: A powerplant is provided that includes a pre-burner, a combustor, a power turbine, a mechanical load and a propellant system. The combustor is fluidly coupled with and downstream of the pre-burner. The power turbine is fluidly coupled with and downstream of the combustor. The mechanical load is rotatably driven by the power turbine. The propellant system is configured to direct fluid oxygen and fluid hydrogen to the pre-burner to provide an oxygen rich fuel mixture for combustion within the pre-burner. The propellant system is also configured to direct the fluid hydrogen to the combustor for combustion within the combustor with oxygen within combustion products received from the pre-burner.

Abstract: An environmental barrier coating, comprising a substrate containing silicon; an environmental barrier layer applied to said substrate; said environmental barrier layer comprising a rare earth composition.

Abstract: An airfoil includes an airfoil wall that has a span between first and second radial ends and that defines leading and trailing edges, pressure and suction sides each joining the leading and trailing edges, and an internal cavity. The internal cavity is divided into at least first and second sub-cavities extending over the span. The first sub-cavity defines a venturi tube.

Abstract: A method of operation is provided during which buffer air flows into a buffer cavity in a turbine engine. The buffer cavity surrounds a bearing compartment in the turbine engine. Leakage air flows across a buffer seal device in the turbine engine. The buffer air and the leakage air are combined to provide combined air. The combined air is vented to a pressure sink such that: a pressure of the buffer air within the buffer cavity is maintained at or below a maximum buffer air threshold during operation of the turbine engine; and a flowrate of the leakage air across the buffer seal device is maintained at or above a minimum leakage air threshold during the operation of the turbine engine.

Abstract: A heat exchanger has: a first manifold assembly having a stack of plates; a second manifold assembly having a stack of plates; and a plurality of tubes extending from the first manifold assembly to the second manifold assembly. The plurality of tubes is a plurality groups of tubes. For each of the groups of the tubes: the tubes of the group have first ends mounted between plates of the first manifold assembly; and the tubes of the group have second ends mounted between plates of the second manifold assembly.

Abstract: A deposition apparatus (20) comprising: a chamber (22); a process gas source (62) coupled to the chamber; a vacuum pump (52) coupled to the chamber; at least two electron guns (26); one or more power supplies (30) coupled to the electron guns; a plurality of crucibles (32,33,34) positioned or positionable in an operative position within a field of view of at least one said electron gun; and a part holder (170) having at least one operative position for holding parts spaced above the crucibles by a standoff height H. The standoff height H is adjustable in a range including at least 22 inches.