A composition is generally provided that includes a silicon-containing material (e.g., silicon metal and/or a silicide) and a boron-doped refractory compound, such as about 0.001% to about 85% by volume of the boron-doped refractory compound (e.g., about 1% to about 60% by volume). In one embodiment, a bond coating on a surface of a ceramic component is generally provided with the bond coating including such a composition, with the silicon-containing material is silicon metal.

A propulsor section includes a propulsor having a plurality of blades rotatable about an engine longitudinal axis. A compressor section includes a low pressure compressor and a high pressure compressor. A turbine section includes a low pressure turbine that drives the propulsor through an epicyclic gear arrangement, and includes a second turbine that drives the high pressure compressor. A power ratio is provided by the combination of a first power input of the low pressure compressor and a second power input of the high pressure compressor. The power ratio is defined by the second power input divided by the first power input. The power ratio is equal to, or greater than, 1.0 and less than, or equal to, 1.4.

An aircraft power plant comprising a monolithic powertrain block with a composition of individual modules grouped by functionality, further comprising electric motors, high power motor controllers, logical control electronics (drivetrain computer), cooling system, hydraulics system, low voltage power system, and high voltage power source, wherein the engine mounting frame of the airplane is the main structure for mounting all individual modules.

A sensor device determines measured values of a property of a fluid, in particular of a gas, in a cavity of a gas turbine engine having a duct for carrying the fluid from the cavity to a sensor element. A data processing device is coupled to the sensor element and processes the measured values. The data processing device has a device for detecting changes in the measured values with respect to time, and an evaluation device, by which the changes in the measured values with respect to time can be detected. If there is a deviation in the changes in the measured values with respect to time from a predefined criterion, a signal relating to an at least partial blockage of the at least one inlet duct can be output. A measurement method is also disclosed.

An apparatus and method for reducing edge contact stress concentrations in a press-fit. The apparatus and method of the present disclosure specifically provide for a press-fit collar having a channel circumscribing a collar axis. The channel having an asymmetrical cross-sectional profile in a radial face. The asymmetrical cross-sectional profile being configured to reduce an edge contact pressure.

An airfoil for a gas turbine engine, which has an airfoil body extending in a spanwise direction and in a chordwise direction, a platform located at an inner end and/or an outer end of the airfoil body, and a fillet at a junction between the airfoil body and the platform. The fillet has a radius distribution at a given chordwise location, the radius distribution varying from the platform to the airfoil body in the spanwise direction. The radius distribution defines a local minimum, the radius of the fillet at the given chordwise location increasing from the local minimum along the spanwise direction toward both of the airfoil and the platform. A local maximum of the radius distribution is offset from the local minimum along the spanwise direction, the radius decreasing from the local maximum along the spanwise direction toward both of the airfoil and the platform.

The disclosure relates to an unmanned aerial vehicle, wherein a fuel cell system component provides a structural component of the vehicle. In some instances propulsion modules affixed to wings are oriented so as to provide airflow to plates of a fuel cell via air inlets for each fuel cell provided at the forward surface of each wing, a fuel cell system component forming a portion of the body and wherein the air inlets are unblocked during flight, each propulsion module is configured to provide air as an oxidant to a fuel cell via the air inlets.

A system can include a gas turbine and a processing system. The gas turbine can include a compressor coupled to a turbine through a shaft. The processing system can be configured to: automatically transition an operating condition of the system through a plurality of operating states; determine an efficiency of the system at each of a plurality of the operating states; for each of the plurality of operating states: select a future operating state of the system based on the determined efficiency of the current operating state.

An electric propulsion system, comprising a propeller and a motor arranged to rotate the propeller, the motor comprising an axial flux motor comprising a rotor disc and a stator disc mounted in face-to-face relationship with an air gap defined therebetween, the rotor disc driven to rotate relative to the stator disc to cause magnetic flux in the air gap to cause rotation of the propeller, characterised in that the propeller is directly attached to the rotor disc to rotate with the rotor disc.

An assembly includes a housing, a carrier, a spring element and a seal element. The housing includes a bore and an annular groove that extends axially along a centerline into the housing from the bore. The carrier projects axially along the centerline into the annular groove. The carrier is configured to translate axially along the centerline relative to the housing. The spring element is arranged within the annular groove. The spring element is configured to bias the carrier axially away from the housing along the centerline. The seal element is mounted to the carrier and arranged within the bore.