Rotary engine with fluid injection cooling

A method of mitigating auto-ignition of a mixture of air and fuel into a combustion chamber of a rotary engine, the combustion chamber defined by an outer body and a rotor received in a rotor cavity of the outer body, the outer body defining a pilot subchamber communicating with the combustion chamber, the method comprising:

• injecting the fuel into the combustion chamber while bypassing the pilot subchamber with a main injector;
• compressing the mixture by decreasing a volume of the combustion chamber with a rotation of the rotor;
• cooling the mixture by injecting a fluid into the combustion chamber while bypassing the pilot subchamber with the main injector;
• and
• igniting the mixture by igniting a pilot mixture of the fuel and the air into the pilot subchamber and by injecting the pilot mixture into the combustion chamber.

A hydrogen-powered rotary engine, comprising:

• an outer body defining a rotor cavity;
• a rotor rotatable within the outer body, the outer body and the rotor defining a combustion chamber of variable volume in the rotor cavity;
• a pilot subchamber defined by the outer body, the pilot subchamber having an outlet in fluid flow communication with the rotor cavity;
• a pilot injector having a pilot tip in communication with the pilot subchamber;
• 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 having a fuel inlet fluidly connected to a source of hydrogen, a fluid inlet fluidly connected to a fluid source, and an injector outlet in fluid communication with the rotor cavity independently of the pilot subchamber, the main injector having:
• a fuel-injection configuration in which the main injector fluidly connects the source of hydrogen to the combustion chamber via the injector outlet;
• and
• a fluid-injection configuration in which the main injector fluidly connects the fluid source to the combustion chamber via the injector outlet.