A flow metering system includes a pump configured to urge a fluid flow from a fluid source, and a recirculation line located at the pump. A pressure regulating valve is located along the recirculating line. One or more fluid delivery lines extend downstream of the pump to deliver the fluid flow to one or more fluid consumers. A flow control valve is located along each fluid delivery line of the one or more fluid delivery lines. A system controller is operably connected to the pressure regulating valve and the one or more flow control valves. The system controller is configured to maintain a selected delta pressure and a selected flow rate of the fluid flow by operation of the pressure regulating valve and the one or more flow control valves.

A fuel sample extractor (FSE) for an aircraft includes a sample chamber, a lid configured to seal the sample chamber, a pump in selective fluid communication with an upper portion of the sample chamber, and a straw in selective fluid communication with a lower portion of the sample chamber and a fuel tank.

A fuel sample extractor (FSE) for an aircraft includes a sample chamber, a lid configured to seal the sample chamber, a pump in selective fluid communication with an upper portion of the sample chamber, and a straw in selective fluid communication with a lower portion of the sample chamber and a fuel tank.

A method for reducing an engine core speed is disclosed, which includes determining a condition of an engine during operation of the engine, and controlling an engine turbine clearance based on the condition of the engine so as to influence the engine core speed. An engine system comprising an engine core speed reducing system is also disclosed.

A method for reducing an engine core speed is disclosed, which includes determining a condition of an engine during operation of the engine, and controlling an engine turbine clearance based on the condition of the engine so as to influence the engine core speed. An engine system comprising an engine core speed reducing system is also disclosed.

A circuit for metering fuel for a turbomachine, including a fuel metering element, a pump designed to pump a flow of fuel to the metering element, and a control valve designed to return, toward the pump, an excess flow of fuel delivered to the metering element as a function of a fuel pressure difference at the terminals of the metering element, the control valve is designed to modulate the excess flow returned toward the pump as a function of variations in the density of the fuel delivered to the metering element. A turbomachine can include such a circuit.

A circuit for metering fuel for a turbomachine, including a fuel metering element, a pump designed to pump a flow of fuel to the metering element, and a control valve designed to return, toward the pump, an excess flow of fuel delivered to the metering element as a function of a fuel pressure difference at the terminals of the metering element, the control valve is designed to modulate the excess flow returned toward the pump as a function of variations in the density of the fuel delivered to the metering element. A turbomachine can include such a circuit.

Fuel systems of gas turbine engines of aircraft, and associated methods are provided. The fuel systems and methods can permit reverse purging of one or more fuel manifolds of a gas turbine engine to prevent coking in some modes of operation. A fuel system includes first and second fuel manifolds fluidly connectable to a combustor of the gas turbine engine. A valve is operatively disposed between the second fuel manifold and a fuel supply line for controlling fuel supply to the second fuel manifold. A reservoir includes a movable piston disposed therein and dividing the reservoir into a first chamber and a second chamber. The first chamber is fluidly connectable to the fuel supply line or to a fuel purge line via the valve. The second chamber is in fluid communication with the second fuel manifold to receive residual fuel from the second fuel manifold.

Fuel systems of gas turbine engines of aircraft, and associated methods are provided. The fuel systems and methods can permit reverse purging of one or more fuel manifolds of a gas turbine engine to prevent coking in some modes of operation. A fuel system includes first and second fuel manifolds fluidly connectable to a combustor of the gas turbine engine. A valve is operatively disposed between the second fuel manifold and a fuel supply line for controlling fuel supply to the second fuel manifold. A reservoir includes a movable piston disposed therein and dividing the reservoir into a first chamber and a second chamber. The first chamber is fluidly connectable to the fuel supply line or to a fuel purge line via the valve. The second chamber is in fluid communication with the second fuel manifold to receive residual fuel from the second fuel manifold.

A system includes a recirculation conduit that recirculates working fluid and a permanent magnet generator module in communication with the recirculation conduit. The working fluid from the recirculation conduit drives the permanent magnet generator module.