Aircraft power plants including combustion engines, and associated methods for recuperating waste heat from such aircraft power plants are described. A method includes transferring the heat rejected by the internal combustion engine to supercritical CO.sub.2 (sCO.sub.2) used as a working fluid in a heat engine. The heat engine converts at least some the heat transferred to the sCO.sub.2 to mechanical energy to perform useful work onboard the aircraft.

An aircraft system is provided that includes a first propulsor rotor, a second propulsor rotor, a drivetrain and an intermittent combustion engine. The first propulsor rotor is rotatable about a first propulsor axis. The second propulsor rotor is rotatable about a second propulsor axis. The drivetrain includes a drive structure and a transmission. The drive structure is rotatable about a drive axis that is angularly offset from the first propulsor axis and the second propulsor axis. An output of the transmission is coupled to the first propulsor rotor and the second propulsor rotor through the drive structure. The intermittent combustion engine is configured to drive rotation of the first propulsor rotor and the second propulsor rotor through the drivetrain.

An aircraft system is provided that includes a first propulsor rotor, a second propulsor rotor, a drivetrain and an intermittent combustion engine. The first propulsor rotor is rotatable about a first propulsor axis. The second propulsor rotor is rotatable about a second propulsor axis. The drivetrain includes a drive structure and a transmission. The drive structure is rotatable about a drive axis that is angularly offset from the first propulsor axis and the second propulsor axis. An output of the transmission is coupled to the first propulsor rotor and the second propulsor rotor through the drive structure. The intermittent combustion engine is configured to drive rotation of the first propulsor rotor and the second propulsor rotor through the drivetrain.

The invention relates to a turbomachine assembly (1) comprising: a compressor (30), an isobaric combustion chamber (40), a piston engine (7) comprising: a shell (70), and a piston (72) movably mounted inside the shell (70) and defining with the shell (70) a variable-volume piston chamber (74), a turbine (50), and a differential transmission mechanism (8).

Aircraft power plants including combustion engines, and associated methods for recuperating waste heat from such aircraft power plants are described. A method includes transferring the heat rejected by the internal combustion engine to supercritical CO.sub.2 (sCO.sub.2) used as a working fluid in a heat engine. The heat engine converts at least some the heat transferred to the sCO.sub.2 to mechanical energy to perform useful work onboard the aircraft.

Aircraft power plants including combustion engines, and associated methods for recuperating waste heat from such aircraft power plants are described. A method includes transferring the heat rejected by the internal combustion engine to supercritical CO.sub.2 (sCO.sub.2) used as a working fluid in a heat engine. The heat engine converts at least some the heat transferred to the sCO.sub.2 to mechanical energy to perform useful work onboard the aircraft.

A propulsion system for an aircraft having a nacelle and a fuselage is provided. The nacelle has a gas flow path and a nacelle interior region. The system includes a compressor section, an intermittent IC engine, a turbine section, a fan, and an IC cooling system. A first electric motor powers the compressor section. The compressor section produces a flow of elevated pressure compressor air. The intermittent IC engine selectively intakes the compressor air flow and produces an exhaust gas flow. The turbine section powered by exhaust gas in turn powers a first electric generator. The fan is driven by a second electric motor. The IC engine cooling system has a heat exchanger disposed within the gas flow path, coolant, coolant piping, and a pump. The heat exchanger is disposed in the nacelle.

A propulsion system for an aircraft having a nacelle and a fuselage is provided. The nacelle has a gas flow path and a nacelle interior region. The system includes a compressor section, an intermittent IC engine, a turbine section, a fan, and an IC cooling system. A first electric motor powers the compressor section. The compressor section produces a flow of elevated pressure compressor air. The intermittent IC engine selectively intakes the compressor air flow and produces an exhaust gas flow. The turbine section powered by exhaust gas in turn powers a first electric generator. The fan is driven by a second electric motor. The IC engine cooling system has a heat exchanger disposed within the gas flow path, coolant, coolant piping, and a pump. The heat exchanger is disposed in the nacelle.

A turbofan engine assembly including a compressor, an intermittent internal combustion engine having an inlet in fluid communication with an outlet of the compressor through at least one first passage of an intercooler, a turbine having an inlet in fluid communication with an outlet of the intermittent internal combustion engine, the turbine compounded with the intermittent internal combustion engine, a bypass duct surrounding the intermittent internal combustion engine, compressor and turbine, and a fan configured to propel air through the bypass duct and through an inlet of the compressor, wherein the intercooler is located in the bypass duct, the intercooler having at least one second passage in heat exchange relationship with the at least one first passage, the at least one second passage in fluid communication with the bypass duct.

A turbine engine system utilizes one or more augmented combustion modules to produce an exhaust that is fed into the turbine portion of the engine and wherein power is produced by the augmented combustion module for use to drive the main shaft and/or for auxiliary purposes. An augmented combustion module is configured between the compressor and the turbine of the engine and receives compressed air from the compressor and ignites an air/fuel-mixture to turn a shaft that can be used to produce power. The shaft may be coupled with an electrical power generator, a pump, a hydraulic or pneumatic power generator and/or power conversion or transmission devices and/or coupled with the main shaft of the turbine engine. The power from a power generator may be stored in a battery, hydraulic accumulator or pneumatic accumulator and may be used to power auxiliary electrical, hydraulic or pneumatic devices.