A compound engine system including a Wankel engine having a recess defined in the peripheral wall of the rotor in each of the three rotating chambers, the recess having a volume of more than 5% of the displacement volume of the chambers. The expansion in the turbine section compensates for the relatively low expansion ratio of the rotary engine.

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.

The invention relates to a charged rotary internal combustion engine with intake air internal cooling (EM), characterized in that in the connection between components to be cooled and the inlet into the working area at least one shut-off device (V) is provided, through which charging pressure can escape.

A rotary engine having an insert in a peripheral wall of the stator body, the insert being made of a material having a greater heat resistance than that of the peripheral wall, having a subchamber defined therein and having an inner surface, the subchamber communicating with the cavity through at least one opening defined in the inner surface and having a shape forming a reduced cross-section adjacent the opening, a pilot fuel injector having a tip received in the subchamber, an ignition element having a tip received in the subchamber, and a main fuel injector extending through the stator body and having a tip communicating with the cavity at a location spaced apart from the insert. The subchamber has a volume corresponding to from 5% to 25% of a sum of the minimum volume and the volume of the subchamber. A method of injecting heavy fuel into a Wankel engine is also discussed.

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.

A non-Wankel rotary engine having an insert in the peripheral wall of the outer body, the insert being made of a material having a greater heat resistance than that of the peripheral wall, having a subchamber defined therein and having an inner surface bordering the cavity, the subchamber communicating with the cavity through at least one opening defined in the inner surface and having a shape forming a reduced cross-section adjacent the opening, a pilot fuel injector having a tip received in the subchamber, an ignition element having a tip received in the subchamber, and a main fuel injector extending through the housing and having a tip communicating with the cavity at a location spaced apart from the insert.

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.

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.

A rotary engine having an insert in a peripheral wall of the stator body, the insert being made of a material having a greater heat resistance than that of the peripheral wall, having a subchamber defined therein and having an inner surface, the subchamber communicating with the cavity through at least one opening defined in the inner surface and having a shape forming a reduced cross-section adjacent the opening, a pilot fuel injector having a tip received in the subchamber, an ignition element having a tip received in the subchamber, and a main fuel injector extending through the stator body and having a tip communicating with the cavity at a location spaced apart from the insert. The subchamber has a volume corresponding to from 5% to 25% of a sum of the minimum volume and the volume of the subchamber. A method of injecting heavy fuel into a Wankel engine is also discussed.

A method of controlling an air intake flow in a rotary engine having primary and secondary inlet ports, including positioning the secondary inlet port rearwardly of the primary inlet port and forwardly of the exhaust port along a direction of a revolution of the rotor, providing independently closable communications between an air source and the primary and secondary inlet ports, and controlling air intake flows between the air source and the primary and secondary inlet ports. Controlling air intake flows includes simultaneously allowing the air intake flow between the primary inlet port and the air source and between the secondary inlet port and the air source. Exhaust gases of the engine are purged with the air intake flow of the secondary inlet port. A rotary engine is also discussed.