A fuel supply system includes a pump to be connected to a fuel tank. A metering valve is downstream of the pump. A control is programmed to control at least one of the pump and metering valve. The control is operable to take in a flow demand signal and a fuel pressure signal from a controller associated with a gas turbine engine. The flow demand signal is indicative of a desired flow volume and the fuel pressure signal is indicative of a desired fuel pressure. Operation conditions are identified for the at least one of said pump and the metering valve. A gas turbine engine and fuel supply system is also disclosed.

A fuel supply control device (10) is configured to generate an operation amount used for feedback-controlling rotation of a gear pump (3) based on a deviation of a detected fuel flow rate with respect to a target flow rate, wherein the fuel supply control device generates the operation amount such that a rotation speed of the gear pump is equal to or greater than a predetermined lower limit rotation speed Nmin so as to protect a bearing of the gear pump.

A fuel supply device includes a first electric pump which discharges a fuel toward an engine at a first flow rate, a second electric pump which discharges the fuel at a second flow rate and merges the fuel discharged at the second flow rate with the fuel discharged at the first flow rate, a first control device which is configured to control the first electric pump, and a second control device which is configured to control the second electric pump, in which the first control device and the second control device control the first electric pump and the second electric pump such that a total flow rate of the first flow rate and the second flow rate is a fuel flow rate target value.

A fuel supply device includes a first electric pump which discharges a fuel toward an engine at a first flow rate, a second electric pump which discharges the fuel at a second flow rate and merges the fuel discharged at the second flow rate with the fuel discharged at the first flow rate, a first control device which is configured to control the first electric pump, and a second control device which is configured to control the second electric pump, in which the first control device and the second control device control the first electric pump and the second electric pump such that a total flow rate of the first flow rate and the second flow rate is a fuel flow rate target value.

A liquid fuel system for an aircraft engine includes a first fuel supply conduit hydraulically connected to a fuel source, a second fuel supply conduit hydraulically connected to the engine, a fuel return conduit hydraulically connected to the second fuel supply conduit, and a fuel pump. The fuel pump has a main inlet hydraulically connected to the first fuel supply conduit, an outlet hydraulically connected to the second fuel supply conduit, and an intermediate inlet hydraulically connected to the fuel return conduit. The intermediate inlet is located between the main inlet and the outlet and in use has a pressure between the main inlet pressure and the outlet pressure. A method of supplying a liquid fuel to an aircraft engine is also described.

A liquid fuel system for an aircraft engine includes a first fuel supply conduit hydraulically connected to a fuel source, a second fuel supply conduit hydraulically connected to the engine, a fuel return conduit hydraulically connected to the second fuel supply conduit, and a fuel pump. The fuel pump has a main inlet hydraulically connected to the first fuel supply conduit, an outlet hydraulically connected to the second fuel supply conduit, and an intermediate inlet hydraulically connected to the fuel return conduit. The intermediate inlet is located between the main inlet and the outlet and in use has a pressure between the main inlet pressure and the outlet pressure. A method of supplying a liquid fuel to an aircraft engine is also described.

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 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. The system can include a primary purge branch configured and a secondary purge branch configured to be in fluid communication with a purge gas line to receive a purge gas flow from the purge gas line.

A transmission device drives a fuel pump for a turbomachine using a drive shaft of said turbomachine. The transmission includes a planet reduction gearing with three elements: a central planet gear, an outer ring gear and a planet carrier. A first of the three elements connects to the drive shaft and a second of the three elements couples to a shaft of the pump. The three elements can be rotated about a shaft of the reduction gearing. First electrical means rotatably drive the third element to modify a rotational speed ratio between the first and second elements. Second electrical means are coupled to the first or the second element. The first and second electrical means are arranged to transfer electrical power reversibly from one to the other.