A fan drive gear system for a turbofan engine includes a geared architecture and a gear controller supporting the geared architecture and controlling rotation of the geared architecture relative a static structure.

The present disclosure concerns control a hybrid electric gas turbine system (300) for an aircraft. The system comprises an electric generator (308) and a gas turbine (309) to form a generator system, an electric motor (303) and a fan (302) to form a propulsor (301), a controller (306) and an electric storage unit (307). After receiving a command for a change in demand for thrust, the controller (306) determines an operational profile that minimises a function comprising a measure of fuel supplied to the gas turbine (309), a transfer of electric power from or to the electric storage unit (307) and a difference between measures of current and demanded thrust over a time period. The controller then operates the electric motor (303), gas turbine (309) and electric storage unit (307) according to the determined operational profile over the time period.

Devices and methods for the efficient disaggregation of tissue samples, separating the tissue into individual intact cells or small aggregates of cells for analysis. A device may include a chamber to receive fluid and a tissue specimen containing more than one cell to be disaggregated. The chamber may include an opening and an agitator in fluid contact with the fluid and the tissue specimen. The agitator may include a micromotor which provides rotational motion to a shaft and an impeller fixed to the shaft such that the impeller and the shaft rotate together upon provision of the rotational motion by the micromotor. The device may include an electrical energy source electrically coupled to the micromotor to rotate the impeller sufficient to disaggregate the one or more individual cells from the tissue specimen and in a manner which does not lyse the one or more individual cells.

A method for operating a gas turbine engine comprises providing fuel flow and compressed airflow to a combustor with a fuel-to-air ratio, the compressed airflow being from a compressed air source; detecting at least one parameter indicative of the fuel-to-air ratio being below a predetermined value; and bleeding compressed air from the compressed air source when the at least one parameter indicative of the fuel-to-air ratio is below the predetermined value to increase the fuel-to-air ratio to at least the predetermined value.

A retaining collar is disclosed for a bayonet mount comprising a rotor disc having a male mounting member defining a pair of apertures and an auxiliary annular wheel defining a plurality of mounting slots. The retaining collar comprises a ring-shaped body and a pair of retention pins. The ring-shaped body has a pair of circumferential end portions separated by a circumferential gap, and an arcuate radial outer surface extending circumferentially between the end portions. The body is dimensioned so that the radial outer surface frictionally engages a radial inner surface of a cylindrical male mounting member in the bayonet mount. The pair of retention pins each extend radially outward from one of the circumferential end portions. Each of the retention pins are dimensioned to extend radially outward from the body through one of said apertures and one of said mounting slots.

An auxiliary power unit (APU) control system for an aircraft is disclosed. The APU control system includes an APU, one or more processors, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the APU control system to receive a one or more ambient signals indicative of an air density value and one or more power signals indicative of a specific amount of power generated by the APU. The APU control system is further caused to determine a variable rotational speed of the APU based on the air density value and instruct the APU to operate at the variable rotational speed. The APU continues to generate the specific amount of power when operating at the variable rotational speed.

An auxiliary power unit (APU) control system for an aircraft is disclosed, and includes an APU drivingly coupled to one or more generators, one or more processors, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the APU control system to receive one or more ambient signals indicative of an air density value and one or more power signals indicative of a specific amount of power generated by the APU. The system is further caused to determine a first variable rotational speed of the APU based on the air density value. The APU continues to generate the specific amount of power when operating at the first variable rotational speed. After instructing the APU to operate at the first variable rotational speed, the system receives an electrical load signal.

The present disclosure relates to gas recovery systems and methods, and systems including gas recovery systems. In some embodiments, a gas recovery system includes a gas inlet, a compressor, a buffer tank, a variable speed microturbine, one or more sensors, and a control system. A gas input into the gas inlet can be output from a processing tool, and the gas can include hydrogen or ammonia gas. The gas can be used to produce electrical power using the first variable speed microturbine. The sensor, for example, a gas analyzer, a flow meter, or a pressure sensor, can be between the gas inlet and the variable speed microturbine. The control system can be configured to control a speed of the variable speed microturbine in response to a measurement from the sensor.

A power turbine control system for a gas turbine engine may comprise a controller comprising one or more processors in communication with the gas turbine engine. The processors may comprise an engine control module configured to receive a torque request signal and generate a torque achieved signal. A rate of change of power turbine speed estimation module may generate an estimated rate of change of power turbine speed signal. A dynamic inversion power turbine governor module may generate the torque request signal based on the torque achieved signal and estimated rate of change of power turbine speed signal.

A unit (1, 10, 100) for generating non-propulsive electrical power for use on board an aircraft, the unit (1, 10, 100) comprising an electricity production device (3, 30) comprising a gas turbine (31) and an electricity generator (32) mechanically connected to an outlet shaft (33) of the gas turbine (31), said electricity generator (32) including output electrical connections (320) for being electrically connected to an electrical power supply network (2, 20, 200) on board an aircraft. The unit (1, 10, 100) includes energy storage means (5) and regulator means (6) configured to control the speed of rotation of the gas turbine (31) as a function of the electrical power required by the on-board electrical power supply network (2, 20, 200).