Abstract: Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on a head-curve relation characterizing the centrifugal pump. The head-curve relation relates the fuel density to the rotational frequency, the flow rate, and pressures at the two different points or the differential pressure between the two different points.

Abstract: Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on an empirically-determined head-curve relation corresponding to the centrifugal pump. The head-curve relation is empirically determined during a characterization phase. The empirically-determined head-curve relation relates the density of the aircraft fuel to the rotational frequency, the flow rate, and the pressures at the two different points.

Abstract: A vacuum system for use with a deoxygenator system includes a housing, a movable assembly positioned within the housing, and a biasing mechanism coupling the movable assembly to the housing. The movable assembly is movable between a first position and a second position within the housing to form a low pressure area between the housing and the movable assembly. A control system including at least one pressure source is arranged in fluid communication with the low pressure area. The control system is operable to selectively communicate fluid from the at least one pressure source to the housing to form the low pressure area.

Abstract: A fuel supply system includes a low flow circuit that branches off parallel to the main flow circuit from the upstream main flow line upstream of the metering valve and has an upstream low flow line having a line connected to an orifice having an upstream side and a downstream side. The downstream side of the orifice is connected to a mass flow meter. A return low flow line is downstream of the mass flow meter and connected into the downstream main flow line at a downstream point. A controller is programmed to take in a low flow circuit mass flow measured by the mass flow meter, and calculate a main mass flow through the main flow circuit and the total mass flow delivered to the engine. A gas turbine engine and a method of operation are also disclosed.

Abstract: A fuel supply system includes a low flow circuit that branches off parallel to the main flow circuit from the upstream main flow line upstream of the metering valve and has an upstream low flow line having a line connected to an orifice having an upstream side and a downstream side. The downstream side of the orifice is connected to a mass flow meter. A return low flow line is downstream of the mass flow meter and connected into the downstream main flow line at a downstream point. A controller is programmed to take in a low flow circuit mass flow measured by the mass flow meter, and calculate a main mass flow through the main flow circuit and the total mass flow delivered to the engine. A gas turbine engine and a method of operation are also disclosed.

Abstract: Apparatus and associated methods relate to measuring density of aircraft fuel. The aircraft fuel is circumferentially pumped about an impeller axis by a centrifugal pump. Differential pressure of the aircraft fuel is measured between two different points within the centrifugal pump, each a different radial distance from an impeller axis. Rotational frequency of the impeller of the centrifugal pump is measured. Density of the aircraft fuel is calculated based on the rotational frequency and the differential pressure.

Abstract: Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on a head-curve relation characterizing the centrifugal pump. The head-curve relation relates the fuel density to the rotational frequency, the flow rate, and pressures at the two different points or the differential pressure between the two different points.

Abstract: Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on an empirically-determined head-curve relation corresponding to the centrifugal pump. The head-curve relation is empirically determined during a characterization phase. The empirically-determined head-curve relation relates the density of the aircraft fuel to the rotational frequency, the flow rate, and the pressures at the two different points.

Abstract: A vacuum assembly includes a housing and a movable assembly positioned within the housing. Movement of the movable assembly relative to the housing creates a low pressure area. A fluid flow conduit is in fluid communication with the low pressure area. A leakage valve is disposed within the fluid flow conduit and is movable between a first position and a second position to restrict a flow through the fluid flow conduit upon detection of an undesired fluid within the low pressure area.

Abstract: Apparatus and associated methods relate to measuring density of aircraft fuel. The aircraft fuel is circumferentially pumped about an impeller axis by a centrifugal pump. Differential pressure of the aircraft fuel is measured between two different points within the centrifugal pump, each a different radial distance from an impeller axis. Rotational frequency of the impeller of the centrifugal pump is measured. Density of the aircraft fuel is calculated based on the rotational frequency and the differential pressure.

Abstract: A pump for a fuel system include a housing, a pumping element, and a takeoff. The housing has an inlet, an outlet, and channel connecting the inlet to the outlet. The pumping element is supported within the housing and bounds the channel. The takeoff is connected to the housing and is in fluid communication with the channel at a location downstream of the inlet, and upstream of the outlet, to divert partially pressurized fuel for cooling an electronic device. Fuel systems and methods of cooling electronic devices are also described.

Abstract: A gas removal unit has a tube bundle formed of a plurality of tubes with a hollow center. The tubes are formed of a material that allows passage of a gas from an exterior of the tube into an interior of the tube and resists flow of at least some liquids through the tube into the interior of the tube. There is a plurality of inner chambers within the bundle and a plurality of outer chambers outward of the bundle. A fluid inlet connects to a first of the inner or outer chambers and a fluid outlet connects to a second of the inner and outer chambers. An axial direction is defined between the fluid inlet to the fluid outlet. A tortuous path is defined by the inner and outer chambers such that a fluid will pass repeatedly from the inner chambers to the outer chambers, and from the outer chambers to the inner chambers, as it moves along the axial direction from the fluid inlet to the fluid outlet. A fuel supply system is also disclosed.

Abstract: A fluid degassing device includes a first housing, a second housing disposed within the first housing, a first flow circuit defined by the second housing and the first housing between a first flow circuit opening and a second flow circuit opening of the first flow circuit, and a tube bundle of selectively permeable membrane tubes disposed in the first flow circuit between the second housing and first housing. The tube bundle is disposed at least partially around a circumference of the second housing and the first flow circuit is defined between the first flow circuit opening of the first flow circuit and the second flow circuit opening such that fuel flows rotationally around the second housing through the tube bundle.

Abstract: A leak detection and mitigation system includes a gas flow path extending from a gas outlet of a fuel degassing device and an orifice in the gas flow path. A sensor is positioned in the gas flow path upstream from the orifice. The sensor is configured to detect a fuel leak into the gas flow path. A method for leak detection and mitigation in a fuel degassing system includes removing gasses from a fuel stream with a fuel degassing device. The method includes directing gasses removed from the fuel stream through a gas flow path extending from a gas outlet of the fuel degassing device. An orifice is positioned in the gas flow path. The method includes detecting a leak from the fuel stream into the gas flow path by measuring a characteristic in the gas flow path upstream from the orifice with a sensor.

Abstract: An oxygen removal system for removing dissolved oxygen from fuel within a fuel system includes a first housing, a second housing, a membrane filter, a piston assembly, and an outlet cap. The first housing extends along a first axis between a first housing first end and a first housing second end. The second housing is disposed about the first housing. The membrane filter is disposed between the first housing and the second housing. The piston assembly has a piston housing that is disposed about the second housing. The piston assembly is arranged to generate a vacuum to remove a fluid from the membrane filter.

Abstract: A pump for a fuel system include a housing, a pumping element, and a takeoff. The housing has an inlet, an outlet, and channel connecting the inlet to the outlet. The pumping element is supported within the housing and bounds the channel. The takeoff is connected to the housing and is in fluid communication with the channel at a location downstream of the inlet, and upstream of the outlet, to divert partially pressurized fuel for cooling an electronic device. Fuel systems and methods of cooling electronic devices are also described.

Abstract: An example method of calibrating a controller for controlling or sensing data from a device includes decoding an encoded image depicted on a surface associated with a device to obtain an identifier of the device and calibration data for an output of the device. The calibration data is utilized by a controller for one of controlling and sensing data from the device. An example system for controlling or sensing data from a device is also disclosed.

Abstract: A gas removal unit has a tube bundle formed of a plurality of tubes with a hollow center. The tubes are formed of a material that allows passage of a gas from an exterior of the tube into an interior of the tube and resists flow of at least some liquids through the tube into the interior of the tube. There is a plurality of inner chambers within the bundle and a plurality of outer chambers outward of the bundle. A fluid inlet connects to a first of the inner or outer chambers and a fluid outlet connects to a second of the inner and outer chambers. An axial direction is defined between the fluid inlet to the fluid outlet. A tortuous path is defined by the inner and outer chambers such that a fluid will pass repeatedly from the inner chambers to the outer chambers, and from the outer chambers to the inner chambers, as it moves along the axial direction from the fluid inlet to the fluid outlet. A fuel supply system is also disclosed.

Abstract: A system for use in a gas turbine engine fuel supply has an internal fuel filter having an internal bore and an external surface. A chamber within the internal bore of the fuel filter for receives a fuel and allows fuel to pass radially outwardly across the fuel filter. An oxygen removal unit is outwardly of the external surface of the fuel filter, such that fuel passes through the fuel filter, encounters the oxygen removal unit such that oxygen can be removed from the fuel, an outlet port for removed oxygen, and a separate outlet port for fuel having passed over the fuel filter and the oxygen removal unit.

Abstract: A gas turbine engine shut-down system includes a pump configured to draw a flow of fuel from a source, a fuel nozzle configured to receive the flow of fuel from the pump, a fuel shut-off valve in fluid communication with the pump, a recirculation circuit for circulating excess fuel to a location upstream of the pump; a solenoid valve in communication with the pump and the recirculation circuit; and a fuel-bypass valve. The fuel-bypass valve includes a first opening connected to the fuel pump, a second opening connected to the fuel shut-off valve, a third opening connected to the recirculation circuit, a fourth opening connected to the solenoid valve, and a piston disposed within the fuel-bypass valve and movable between a plurality of positions.