Abstract: A metering valve spool controls a volume of fuel passing through a metering valve. The spool has a forward face. A line from a pump has a connection into a chamber. The face of the metering valve spool may contact a seal to block flow into the chamber. The metering valve is connected to a pressure regulating valve. The pressure regulating valve is to be connected to a combustor. A control selectively moves the metering valve spool to control a volume of fuel delivered from the chamber to the pressure regulating valve. The control is also programmed to move the metering valve spool to a position where a forward face of the metering valve spool seals on the seal to block flow from the pump from reaching the pressure regulating valve, and also from reaching the tap. A gas turbine engine is also disclosed.

Abstract: A fuel system can include a total flow line configured to receive a total flow and a primary flow line connected to the total flow line. The primary flow line can be in fluid communication with one or more primary fuel nozzles of a nozzle assembly. The fuel system can include a secondary flow line connected to the total flow line in parallel with the primary flow line, the secondary flow line in fluid communication with a plurality of secondary flow nozzles of the nozzle assembly. The fuel system can include a flow split system configured to control a flow split between a primary flow of the primary flow line and a secondary flow of the secondary flow line.

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: A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, and a primary flow valve disposed between the primary flow line and the main flow line and configured to allow injectant flow to the primary flow line from the main flow line in an open primary flow valve state, and to prevent injectant flow to the primary flow line from the main flow line in a closed primary flow valve state. The system can include a secondary flow line connected to the main flow line and a secondary flow valve disposed between the secondary flow line and the main flow line and configured to selectively allow injectant flow to the secondary flow line from the main flow line in an open secondary flow valve state, and to prevent injectant flow to the secondary flow line from the main flow line in a closed secondary flow valve state.

Abstract: A fuel supply system for a gas turbine engine includes a fuel tank, a pumping unit downstream of the fuel tank and configured to receive fuel from the fuel tank, and a sharing valve downstream of the pumping unit and configured to receive fuel from the cruise pump of the pumping unit during a first operating condition. The pumping unit includes a boost pump, an actuation pump downstream of the boost pump and in fluid communication with at least one actuator of the gas turbine engine, and a cruise pump downstream of the boost pump and in fluid communication with nozzles of a gas generator of the gas turbine engine.

Abstract: A fluid injection system can include a main flow line, a primary flow line connected to the main flow line, and a primary flow valve disposed between the primary flow line and the main flow line and configured to allow injectant flow to the primary flow line from the main flow line in an open primary flow valve state, and to prevent injectant flow to the primary flow line from the main flow line in a closed primary flow valve state. The system can include a secondary flow line connected to the main flow line and a secondary flow valve disposed between the secondary flow line and the main flow line and configured to selectively allow injectant flow to the secondary flow line from the main flow line in an open secondary flow valve state, and to prevent injectant flow to the secondary flow line from the main flow line in a closed secondary flow valve state.

Abstract: A system includes a flow inlet conduit and a primary conduit that branches from the flow inlet conduit for delivering flow to a set of primary nozzles. An equalization bypass valve (EBV) connects between the flow inlet conduit and a secondary conduit for delivering flow to a set of secondary nozzles. The EBV is connected to an equalization conduit (EC). A pressure equalization solenoid is connected to the EC to selectively connect a servo supply pressure conduit and/or a return pressure (PDF) conduit into fluid communication with the EC. An EBV rate limiting orifice (RLO) is connected in the PDF conduit. A bypass conduit branches from the PDF conduit on a first side of the EBV RLO and reconnects to the PDF conduit on a second side of the EBV RLO. An orifice bypass valve (OBV) is connected to the bypass conduit and acts to selectively bypass the EBV RLO.

Abstract: A fuel device including a housing having at least one fuel channel configured to direct, meter, sense or pump fuel there through, and a characterization device coupled to the housing including a memory chip, wherein the memory chip includes measured performance data of the fuel channel.

Abstract: A method can include receiving, at a control module, first pump characteristic data from a data source associated with a pump, sensing second pump characteristic data from a flow system using one or more sensors, comparing the first pump characteristic data to the second pump characteristic data sensed in the flow system, and determining a health of the pump based on the comparison of the first pump characteristic data to the second pump characteristic data.

Abstract: A fuel system including a fuel tank, a first pump fluidly coupled to the fuel tank configured for distributing fuel from the fuel tank throughout the fuel system, and a second pump fluidly coupled to the first pump by a pressure regulating valve and configured for driving fuel to an engine.

Abstract: A fuel supply system for a gas turbine engine includes a fuel tank, a pumping unit downstream of the fuel tank and configured to receive fuel from the fuel tank, and a sharing valve downstream of the pumping unit and configured to receive fuel from the cruise pump of the pumping unit during a first operating condition. The pumping unit includes a boost pump, an actuation pump downstream of the boost pump and in fluid communication with at least one actuator of the gas turbine engine, and a cruise pump downstream of the boost pump and in fluid communication with nozzles of a gas generator of the gas turbine engine.

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: 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 fluid injection system can include a main flow line, a primary flow line connected to the main flow line, and a primary flow valve disposed between the primary flow line and the main flow line and configured to allow injectant flow to the primary flow line from the main flow line in an open primary flow valve state, and to prevent injectant flow to the primary flow line from the main flow line in a closed primary flow valve state. The system can include a secondary flow line connected to the main flow line and a secondary flow valve disposed between the secondary flow line and the main flow line and configured to selectively allow injectant flow to the secondary flow line from the main flow line in an open secondary flow valve state, and to prevent injectant flow to the secondary flow line from the main flow line in a closed secondary flow valve state.

Abstract: A fuel system for an engine including a first flow line, an electrically driven startup pump in fluid communication with the first flow line to provide a startup flow, a main flow line, a main pump in fluid communication with the main flow line to provide a main flow, and a switching valve connected to the first flow line and the main flow line, the switching valve configured to select between the first flow line and the main flow line to output either the startup flow or the main flow.

Abstract: A fuel system can include a total flow line configured to receive a total flow and a primary flow line connected to the total flow line. The primary flow line can be in fluid communication with one or more primary fuel nozzles of a nozzle assembly. The fuel system can include a secondary flow line connected to the total flow line in parallel with the primary flow line, the secondary flow line in fluid communication with a plurality of secondary flow nozzles of the nozzle assembly. The fuel system can include a flow split system configured to control a flow split between a primary flow of the primary flow line and a secondary flow of the secondary flow line.

Abstract: A fuel system with integrated thrust control malfunction and overspeed protection includes a centrifugal pump for receiving filtered fuel and supplying fuel to a metering and pressure regulating valve, the metering and pressure regulating valve for metering discharge of filtered fuel flow to a gas turbine engine burner, a shut off valve downstream of the metering and pressure regulating valve movable from an open position to either a fully closed position configured for providing rapid shutoff or a partially closed position configured for reduction of fuel flow to the gas turbine engine burner, and a first solenoid and a second solenoid for controlling the shut off valve position.