US Patent 12006882 Rotary engine with dual-fuel injectors

A rotary engine, has: an outer body defining a rotor cavity; a rotor within the rotor cavity and defining at least one chamber; a pilot subchamber defined by the outer body and having an outlet in communication with the rotor cavity; a main fuel source of a heavy fuel; an alternative fuel source of an alternative fuel; a main injector having a tip in communication with the rotor cavity at a location spaced apart from the outlet of the pilot subchamber, the main injector selectively fluidly connectable to the main fuel source or to the alternative fuel source; and a controller configured for: determining that the rotary engine is in a vicinity of a city or an airport; and operating the main injector in a first configuration in which the main injector fluidly connects the alternative fuel source to the rotor cavity while disconnecting the main fuel source.