Aircraft propulsion system with intermittent combustion engine and electric transmission system and method for operating the same

An aircraft propulsion system for an aircraft having a nacelle and a fuselage, the nacelle having a gas flow path and a nacelle interior region disposed radially inside of the gas flow path, the system comprising:

• a compressor section powered by a first electric motor, the compressor section configured to be disposed in the nacelle interior region and to receive air entering the nacelle, and configured to selectively produce a flow of compressor air at an air pressure greater than an ambient air pressure;
• an intermittent internal combustion (IC) engine configured to selectively intake the flow of compressor air during operation and produce an exhaust gas flow during operation;
• a turbine section in communication with and configured to power a first electric generator configured to produce electrical power, wherein the turbine section is powered by the exhaust gas flow;
• a first fan rotationally driven by a second electric motor about a first rotational axis, the first fan having a first hub centered on the first rotational axis and a plurality of first fan blades extending radially outward from the first hub, wherein the first hub is configured to be disposed in the nacelle interior region and the plurality of first fan blades are configured to extend into the gas flow path, wherein the first fan is positioned downstream of the compressor section;
• and
• an IC engine cooling system having at least one heat exchanger and at least one pump configured to provide coolant communication between the intermittent IC engine and the at least one heat exchanger, the at least one heat exchanger disposed in communication with the gas flow path of the nacelle.

A method of powering an aircraft having a fuselage and a nacelle, the nacelle defining an annular gas flow path and having a nacelle interior region disposed radially inside of the gas flow path, the method comprising:

• driving a compressor section using a first electric motor to selectively produce a flow of compressor air at an air pressure greater than an ambient air pressure, the compressor section disposed within the nacelle interior region and disposed to receive air entering the at least one nacelle;
• operating an intermittent internal combustion (IC) engine using the flow of compressor air, the IC engine operated to drive at least one first electric generator to produce electrical power and to produce an exhaust gas flow during operation, wherein the intermittent IC engine and the at least one first electric generator are disposed in the fuselage;
• operating a turbine section to drive a second electric generator to produce electrical power, the turbine section powered using the exhaust gas flow;
• rotationally driving at least one fan about a rotational axis using a second electric motor powered by electrical power produced by the at least one first electrical generator, or the second electrical generator, or both, to force ambient air through the gas flow path, the fan having a first hub centered on the rotational axis and a plurality of fan blades extending radially outward from the hub, and the plurality of first fan blades extending into the gas flow path, wherein the first fan is positioned downstream of the compressor section;
• and
• pumping a volume of coolant through a cooling system having at least one heat exchanger and a pump, the IC engine cooling system configured to provide coolant communication between the intermittent IC engine and the at least one heat exchanger, the at least one heat exchanger disposed in communication with the gas flow path of the at least one nacelle.