Abstract: A rotary internal combustion engine including a rotor assembly where at least a first and a second of the combustion chambers have unequal theoretical volumetric ratios. Also, a rotary internal combustion engine including first and second rotor assemblies where at least one of the combustion chambers of the first rotor assembly and at least one of the combustion chambers of the second rotor assembly have unequal effective volumetric compression ratios and/or unequal effective volumetric expansion ratios.

Abstract: A method of operating an engine assembly receiving fuel, including admitting atmospheric air at a temperature T1 through an inlet of a compressor having a pressure ratio of PRGT, compressing the air in the compressor, cooling the compressed air from the compressor through an intercooler to cool the air from a temperature TBIC to a temperature TAIC, delivering the cooled compressed air from the intercooler to an inlet of an intermittent internal combustion engine having an effective volumetric compression ratio rVC, and further compressing the air in the intermittent internal combustion engine before igniting the fuel, where ( PR GT ) a ? ( r VC ) b ? ( T AIC T BIC ) ? ( T 1 T A ) < 1. An engine assembly is also discussed.

Abstract: An engine assembly including an engine core including at least one internal combustion engine each including a rotor sealingly and rotationally received within a respective internal cavity to provide rotating chambers of variable volume in the respective internal cavity, a compressor having an outlet in fluid communication with an inlet of the engine core, a first intake conduit in fluid communication with an inlet of the compressor and with a first source of air, a second intake conduit in fluid communication with the inlet of the compressor and with a second source of air warmer than the first source of air, and a selector valve configurable to selectively open and close at least the fluid communication between the inlet of the compressor and the first intake conduit. A method of supplying air to a compressor is also discussed.

Abstract: There is disclosed an engine assembly, including an internal combustion engine having a housing and a coolant circuitry in heat exchange relationship with the housing. A porous surface is configured for defining a portion of an external surface of an aircraft. Apertures are defined through the porous surface. The housing of the internal combustion engine is in heat exchange relationship with the porous surface for heating the porous surface. An air conduit has an inlet fluidly connected to a boundary layer region outside the engine assembly and adjacent the porous surface via the apertures of the porous surface. The air conduit is in heat exchange relationship with the coolant circuitry. A forced air system is fluidly connected to the inlet of the air conduit and is operable to draw an airflow from the inlet and inside the air conduit. A method of operating the engine assembly is disclosed.

Abstract: An engine assembly has an engine core comprising at least two stacks of rotary internal combustion engines drivingly connected to a common load. The engine further comprises a compressor section having an outlet in fluid communication with an inlet of the engine core, and a turbine section having an inlet in fluid communication with an outlet of the engine core.

Abstract: A rotary engine where the rotor cavity has a peripheral inner surface having a peritrochoid configuration defined by a first eccentricity and the rotor has a peripheral outer surface having a peritrochoid inner envelope configuration defined by a second eccentricity larger than the first eccentricity. Also, a rotary engine where the rotor cavity has a peripheral inner surface having a peritrochoid configuration defined by an eccentricity, and a rotor with a peripheral outer surface between adjacent ones of the apex portions being inwardly offset from a peritrochoid inner envelope configuration defined by the eccentricity. The engine may have an expansion ratio with a value of at most 8. The rotary engine may be part of a compound engine system.

Abstract: A compound engine assembly with an engine core including at least one internal combustion engine, a compressor, and a turbine section where the turbine shaft is configured to compound power with the engine shaft. The turbine section may include a first stage turbine and a second stage turbine. The turbine shaft is rotationally supported by a plurality of bearings all located on a same side of the compressor rotor(s) and all located on a same side of the turbine rotor(s), for example all located between the compressor rotor(s) and the turbine rotor(s), such that the compressor rotor(s) and the turbine rotor(s) are cantilevered. A method of driving a rotatable load of an aircraft is also discussed.

Abstract: A compound engine assembly for use as an auxiliary power unit for an aircraft and including an engine core with internal combustion engine(s), a compressor having an outlet in fluid communication with an engine core inlet, a bleed conduit in fluid communication with the compressor outlet through a bleed air valve, and a turbine section having an inlet in fluid communication with the engine core outlet and configured to compound power with the engine core. The turbine section may include a first stage turbine having an inlet in fluid communication with the engine core outlet and a second stage turbine having an inlet in fluid communication the first stage turbine outlet. A method of providing compressed air and electrical power to an aircraft is also discussed.

Abstract: A rotary engine including a rotor sealingly received within an internal cavity of an outer body to define a plurality of combustion chambers having a variable volume, a pilot subchamber located in a wall of the outer body, the pilot subchamber in fluid communication with the internal cavity via at least two spaced apart transfer holes defining a flow restriction between the pilot subchamber and the internal cavity, a pilot fuel injector in fluid communication with the pilot subchamber, an ignition element configured for igniting fuel in the pilot subchamber, and a main fuel injector extending through the stator body and communicating with the cavity at a location spaced apart from the pilot subchamber. A method of combusting fuel in a rotary engine is also discussed.

Abstract: A compound engine system includes a rotary engine with rotating chambers, a compressor section in successive communication with the rotating chambers, and a turbine section in successive communication with the rotating chambers. The turbine section has an output shaft. The output shaft and the engine shaft are drivingly engaged to each other and wherein the turbine section has a power output corresponding to from 20% to 35% of a total power output of the compound engine system. A method of compounding power in a compound engine system is also discussed.

Abstract: A method of operating an engine assembly receiving fuel, including admitting atmospheric air at a temperature T1 through an inlet of a compressor having a pressure ratio of PRGT, compressing the air in the compressor, cooling the compressed air from the compressor through an intercooler to cool the air from a temperature TBIC to a temperature TAIC, delivering the cooled compressed air from the intercooler to an inlet of an intermittent internal combustion engine having an effective volumetric compression ratio rVC, and further compressing the air in the intermittent internal combustion engine before igniting the fuel, where ( PR GT ) a ? ( r VC ) b ? ( T AIC T BIC ) ? ( T 1 T A ) < 1. An engine assembly is also discussed.

Abstract: An engine assembly including an engine core including at least one internal combustion engine each including a rotor sealingly and rotationally received within a respective internal cavity to provide rotating chambers of variable volume in the respective internal cavity, a compressor having an outlet in fluid communication with an inlet of the engine core, a first intake conduit in fluid communication with an inlet of the compressor and with a first source of air, a second intake conduit in fluid communication with the inlet of the compressor and with a second source of air warmer than the first source of air, and a selector valve configurable to selectively open and close at least the fluid communication between the inlet of the compressor and the first intake conduit. A method of supplying air to a compressor is also discussed.

Abstract: A compound engine assembly including a common air conduit having an inlet in fluid communication with ambient air, a compressor, at least one internal combustion engine having an inlet in fluid communication with an outlet of the compressor, a turbine section having an inlet in fluid communication with an outlet of the at least one internal combustion engine, the turbine section configured to compound power with the at least one internal combustion engine, and at least one heat exchanger in fluid communication with the common air conduit, each of the at least one heat exchanger configured to circulate a fluid of the engine assembly in heat exchange relationship with an airflow from the common air conduit circulating therethrough. The compressor has an inlet in fluid communication with the common air conduit upstream of the at least one heat exchanger. The internal combustion engine may be a reciprocating engine.

Abstract: A compound engine assembly with an engine core including at least one internal combustion engine, a turbine section, and a compressor having an outlet in fluid communication with an inlet of the engine core. A casing is connected to the turbine section, the compressor and the engine core. A mount cage is connected to mounts attached to the casing between the compressor and a hot zone including the turbine section and the engine core. The mount cage includes a plurality of struts all extending from the mounts away from the turbine section and engine core. The casing may be a gearbox module casing through which the turbine shaft in engaged with the engine shaft. The mount cage may be completely contained within an axial space with the turbine section and engine core being located outside of the axial space.

Abstract: A compound engine assembly with an engine core including at least one internal combustion engine, a turbine section, and a compressor having an outlet in fluid communication with an inlet of the engine core. A casing is connected to the turbine section, compressor and engine core. A mount cage is connected to mounts attached to the casing between the compressor and a hot zone including the turbine section and exhaust pipe(s). The struts are separated from the hot zone by at least one firewall. The mount cage may include a plurality of struts all extending from the mounts away from the turbine section and engine core. The casing may be a gearbox module casing through which the turbine shaft in engaged with the engine shaft. The mount cage may be completely contained within an axial space with the turbine section and exhaust pipe(s) being located outside of the axial space.

Abstract: A rotary engine includes an insert having a pilot subchamber defined therein and communicating with the internal cavity of the engine. A pilot fuel injector has a tip in communication with the pilot subchamber. An ignition element extends into an element cavity defined through the insert adjacent the pilot subchamber. The element cavity is in communication with the pilot subchamber through a communication opening defined in the insert between the element cavity and the pilot subchamber. The communication opening is smaller than a portion of the ignition element adjacent the communication opening such as to prevent the portion of the ignition element from completely passing through the communication opening upon breaking off of the portion of the ignition element from a remainder of the ignition element. An outer body for a rotary engine and a method of combusting fuel in a rotary engine are also provided.

Abstract: An engine assembly includes an engine compartment containing an internal combustion engine and a cooler compartment adjacent the engine compartment containing a heat exchanger. The engine and cooler compartments have an opening defined therebetween. A forced air system is operable to drive an airflow. A method for cooling the engine and its compartment is disclosed.

Abstract: A rotary internal combustion engine including a rotor assembly where at least a first and a second of the combustion chambers have unequal theoretical volumetric ratios. Also, a rotary internal combustion engine including first and second rotor assemblies where at least one of the combustion chambers of the first rotor assembly and at least one of the combustion chambers of the second rotor assembly have unequal effective volumetric compression ratios and/or unequal effective volumetric expansion ratios.

Abstract: An auxiliary power unit assembly for an aircraft, including an engine assembly including an internal combustion engine, a first duct in fluid communication with an inlet of the internal combustion engine and configured to be in fluid communication with an environment of the aircraft, and a second duct configured to be in fluid communication with the environment. The second duct may be in fluid communication with an inlet of a compressor drivable by the internal combustion engine or with a compartment receiving the engine assembly. A filter extends across the first duct. The filter is removable from the first duct through an opening in a wall of the first duct, the opening accessible from an exterior of the engine assembly.

Abstract: An inlet assembly for an auxiliary power unit for an aircraft, including a particle separator and a plenum having first and second inlets. A first duct configured to deliver air to an engine of the auxiliary power unit is in fluid communication with an outlet of the plenum. A second duct configured to deliver air to a compartment containing the auxiliary power unit is in fluid communication with the outlet of the plenum. The assembly is selectively configurable between a first configuration where the plenum is in fluid communication with the environment of the aircraft through the second inlet and through the particle separator, and a second configuration where the plenum is in fluid communication with the environment of the aircraft through the first inlet independently of the particle separator. An auxiliary power unit assembly and a method of feeding air to an auxiliary power unit assembly are also discussed.