Abstract: A method includes using an electric motor to start a thermal engine. The electric motor and thermal engine are connected to one another as the electric motor and the thermal engine of a hybrid-electric power plant in an aircraft. The electric motor can be connected to a combining gear box. The thermal engine can be connected to the combining gear box so that the electric motor and the thermal engine can provide torque to the combining gear box in a parallel hybrid-electric configuration. The combining gearbox can output torque to an air mover for providing thrust to the aircraft.

Abstract: A seal for an aircraft engine includes an annular body receivable in interference fit in a radial spacing defined between inner and outer cylindrical components of the aircraft engine, the annular body defining a central axis coaxial with the inner and outer cylindrical components, the annular body including an inner portion defining an inner diameter, an outer portion defining an outer diameter, and an intermediate portion extending between the inner and outer portions. The outer portion is slidably engageable to the outer cylindrical component at an outer contact sealing portion of the annular body. One of the inner portion and the outer portion defines at least one cut extending from the one of the inner portion and the outer portion toward another one of the inner portion and the outer portion. A method for sealing a radial spacing between coaxial cylindrical components in an aircraft engine is also described.

Abstract: Aircraft engine oil tanks, lubrication systems, and associated methods are provided. The oil tank includes a first tank portion defining a first volume for holding oil and a second tank portion defining a second volume for holding oil, in fluid communication with the first volume. The first tank portion includes an oil outlet for delivering oil to a lubrication load via a pump. The first volume is in fluid communication with a vent opening for venting the oil tank. At least part of the second tank portion is disposed higher than the vent opening for retaining a quantity of oil inside the oil tank during a negative-g force flight condition and facilitate the recovery of the lubrication system following the negative-g force flight condition.

Abstract: A rotodynamic pump for pumping a fluid includes an impeller, a housing surrounding the impeller, and a pressure regulating mechanism. The pressure regulating mechanism is configured to adjust the clearance between the impeller and the impeller housing to regulate pressure of the fluid downstream of the impeller. A method of regulating the delivery pressure is also disclosed.

Abstract: A method includes using an electric motor to start a thermal engine. The electric motor and thermal engine are connected to one another as the electric motor and the thermal engine of a hybrid-electric power plant in an aircraft. The electric motor can be connected to a combining gear box. The thermal engine can be connected to the combining gear box so that the electric motor and the thermal engine can provide torque to the combining gear box in a parallel hybrid-electric configuration. The combining gearbox can output torque to an air mover for providing thrust to the aircraft.

Abstract: A method of controlling a delivery pressure of an aircraft engine fuel system includes operating a rotodynamic fuel pump hydraulically connected to the fuel system to pump a fluid from an inlet of the rotodynamic pump and out of an outlet of the rotodynamic pump for delivery to the fuel system. The method further includes varying an angular relationship between the inlet and the outlet of the pump to control the delivery pressure. An aircraft engine fuel system and a rotodynamic pump are also described.

Abstract: 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.

Abstract: A rotary internal combustion engine (ICE) has: a housing defining a rotor cavity; a rotor received within the rotor cavity to define working chambers of variable volume around the rotor, the rotor having circumferentially spaced peripheral apex seals biased radially outwardly in sliding engagement against a peripheral wall of the housing to separate the working chambers from one another, the housing having a fluid passage defined therethrough and opening into an inner surface of the peripheral wall; and an injector having a lubricant inlet hydraulically connected to a lubricant source, an actuation inlet hydraulically connected to a source of an actuation fluid, and a lubricant outlet, the injector having an open state in which the lubricant outlet is in fluid flow communication with the fluid passage upon the actuation fluid received within the injector and a closed state in which the lubricant outlet is disconnected from the fluid passage.

Abstract: A rotary internal combustion engine (ICE) has: a housing defining a rotor cavity; a rotor received within the rotor cavity to define working chambers of variable volume around the rotor, the rotor having circumferentially spaced peripheral apex seals biased radially outwardly in sliding engagement against a peripheral wall of the housing to separate the working chambers from one another, the housing having a fluid passage defined therethrough and opening into an inner surface of the peripheral wall; and an injector having a lubricant inlet hydraulically connected to a lubricant source, an actuation inlet hydraulically connected to a source of an actuation fluid, and a lubricant outlet, the injector having an open state in which the lubricant outlet is in fluid flow communication with the fluid passage upon the actuation fluid received within the injector and a closed state in which the lubricant outlet is disconnected from the fluid passage.

Abstract: There is disclosed an engine assembly for an aircraft, including: a combustion engine including a coolant circuit in heat exchange relationship with a heat sink, the heat sink including a heat exchanger and at least one component, the at least one component having a main function that differs from thermal exchange. A method of operating the system is also disclosed.

Abstract: A fuel injection system for an aircraft engine has: a first fuel injector having a first actuation inlet, a first fuel inlet connected to a fuel source, and a first fuel outlet connected to the at least one combustion chamber, the first fuel injector defining a first pressure ratio; a second fuel injector having a second actuation inlet, a second fuel inlet connected to the fuel source, and a second fuel outlet connected to the at least one combustion chamber, the second fuel injector defining a second pressure ratio; and an actuation fluid system having a circuit connected to the first actuation inlet and to the second actuation inlet, the first outlet pressure different than the second outlet pressure by having one or both of the first pressure ratio different than the second pressure ratio and a first actuation pressure different than a second actuation pressure.

Abstract: A method of operating an aircraft engine of an aircraft, the aircraft engine having a common-rail fuel injection system for injecting fuel into a combustion chamber of the aircraft engine, including: pressurizing fuel for circulation through the common-rail injection system; circulating a portion of the pressurized fuel through a motive flow inlet of an ejector pump; and entraining a flow through the ejector pump with the portion of the pressurized fuel circulating through the motive flow inlet.

Abstract: There is disclosed a method of operating an engine assembly, including: driving a load with an internal combustion engine and an output of a turbine section, the turbine section driven by combustion gases from an exhaust the internal combustion engine; and injecting fuel upstream of the turbine section and downstream of the exhaust of the internal combustion engine. An engine assembly having a secondary injector for injecting fuel upstream of the turbine section and downstream of the combustion engine is also disclosed.

Abstract: A method of operating an aircraft engine of an aircraft, the aircraft engine having a common-rail fuel injection system for injecting fuel into a combustion chamber of the aircraft engine, including: pressurizing fuel for circulation through the common-rail injection system; circulating a portion of the pressurized fuel through a motive flow inlet of an ejector pump; and entraining a flow through the ejector pump with the portion of the pressurized fuel circulating through the motive flow inlet.

Abstract: There is disclosed a method of operating an engine assembly including a combustion engine and a common-rail injector. The method includes: injecting fuel into a combustion chamber of the combustion engine via the common-rail injector thereby generating a backflow of fuel; and powering an actuator using at least a portion of the backflow of fuel. An engine assembly including the combustion engine is disclosed; the engine assembly having a fuel circuit fluidly connecting a fuel source, the common-rail injector, and the second injector outlet together. The fuel circuit has an actuator sub-circuit operatively connected to an outlet of the common-rail injector and an actuator fluidly connected to the actuator sub-circuit.

Abstract: A method of controlling a delivery pressure of an aircraft engine fuel system includes operating a rotodynamic fuel pump hydraulically connected to the fuel system to pump a fluid from an inlet of the rotodynamic pump and out of an outlet of the rotodynamic pump for delivery to the fuel system. The method further includes varying an angular relationship between the inlet and the outlet of the pump to control the delivery pressure. An aircraft engine fuel system and a rotodynamic pump are also described.

Abstract: There is disclosed a method of operating an engine assembly, including: driving a load with an internal combustion engine and an output of a turbine section, the turbine section driven by combustion gases from an exhaust the internal combustion engine; and injecting fuel upstream of the turbine section and downstream of the exhaust of the internal combustion engine. An engine assembly having a secondary injector for injecting fuel upstream of the turbine section and downstream of the combustion engine is also disclosed.

Abstract: A rotodynamic pump for pumping a fluid includes an impeller, a housing surrounding the impeller, and a pressure regulating mechanism. The pressure regulating mechanism is configured to adjust the clearance between the impeller and the impeller housing to regulate pressure of the fluid downstream of the impeller. A method of regulating the delivery pressure is also disclosed.

Abstract: A liquid tank system comprises a main liquid tank, an outlet communicating between a fluid circuit and the main liquid tank, an inlet communicating between the fluid circuit and the main liquid tank, and an auxiliary cavity. First vent passage and second vent passage(s) communicate between the main liquid tank and the auxiliary cavity and allows liquid and gas to flow from the main liquid tank to the auxiliary cavity. The second vent passage has a flow control device regulating flow through the second vent passage and having a set point at which it allows liquid and gas to flow from the main liquid tank to the auxiliary cavity only when a pressure in the main liquid tank is beyond a threshold.

Abstract: 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.