An auxiliary power unit for an aircraft, having a compressor, an intercooler including first conduit(s) having an inlet in fluid communication with the compressor outlet and second conduit(s) configured for circulation of a coolant therethrough, an engine core having an inlet in fluid communication with an outlet of the first conduit(s), and a bleed conduit in fluid communication with the outlet of the first conduit(s) through a bleed air valve. The auxiliary power unit may include a generator in driving engagement with the shaft of the engine core to provide electrical power for the aircraft. A method of providing compressed air and electrical power to an aircraft is also discussed.

An enhanced pressure-wave supercharger for a combustion engine utilizes a superior pressure wave process cycle design. The design utilizes a select final portion of the compressed gas stream exiting the rotor, and supplies it to a subsequent inlet port ahead of and prior to the introduction into the rotor of the aspirated air to be compressed. Work is extracted within the rotor from this gas stream and transferred into rotational energy of the rotor through using a portion the available momentum of the compressed gas via incidence on the rotor webs to turn the rotor by means of conventional turbomachinery principles.

An auxiliary power unit for an aircraft, having a compressor, an intercooler including first conduit(s) having an inlet in fluid communication with the compressor outlet and second conduit(s) configured for circulation of a coolant therethrough, an engine core having an inlet in fluid communication with an outlet of the first conduit(s), and a bleed conduit in fluid communication with the outlet of the first conduit(s) through a bleed air valve. The auxiliary power unit may include a generator in driving engagement with the shaft of the engine core to provide electrical power for the aircraft. A method of providing compressed air and electrical power to an aircraft is also discussed.

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.

A compound engine assembly with an inlet duct, a compressor, an engine core including at least one internal combustion engine, and a turbine section including a turbine shaft 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 and the engine shaft are parallel to each other. The turbine shaft, the engine shaft and at least part of the inlet duct are all radially offset from one another. A method of driving a rotatable load of an aircraft is also discussed.

A method for starting a turbocompounded engine system having an internal combustion engine and a turbomachinery driving a load, the method comprising: mechanically disengaging the internal combustion engine from at least one of the load and/or the turbomachinery before starting the internal combustion engine. The engine is allowed to warm up and then the engine is re-engaged with the at least one of the load and the turbomachinery.

There is disclosed an aircraft engine assembly including an engine having an engine shaft; an output shaft; a clutch in driving engagement between the engine shaft and the output shaft. The clutch has a first component in driving engagement with the engine shaft and a second component. The clutch is operable between first and second configurations. In the first configuration, the first component is rotatable relative to the second component and the engine shaft is rotatable relative to the output shaft. In the second configuration, the first and second components are engaged with one another and the engine shaft rotates with the output shaft. A mechanical lock is operable between first and second positions. In the first position, the mechanical lock is disengaged from the first component. In the second position, the first and second components are secured for joint rotation one relative to the other.

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.

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.

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.