Method of operating a rotating detonation combustor

A method of operating a rotating detonation combustor, the rotating detonation combustor including (a) a detonation chamber defined by an outer wall, an inner wall, and an upstream wall, (b) an outlet at a downstream end of the detonation chamber, the detonation chamber having a detonation chamber length defined by a distance extending from the upstream wall to the outlet, (c) an air plenum arranged upstream of the detonation chamber, (d) an air inlet arranged in fluid communication with the air plenum and with the detonation chamber, (e) a fuel plenum, (f) at least one fuel injector arranged to inject fuel from the fuel plenum into one of the air inlet or the detonation chamber, and (g) an auxiliary gas injection port arranged to provide a flow of an auxiliary gas into one of the air inlet or into an upstream end of the detonation chamber, the method comprising:

• providing a flow of air from the air plenum through the air inlet to flow into the detonation chamber;
• providing a flow of fuel from the at least one fuel injector to mix with the flow of air from the air plenum in one of the air inlet or in the detonation chamber;
• mixing the flow of the fuel and the flow of the air in one of the air inlet or in the detonation chamber to generate a fuel-air mixture;
• detonating the fuel-air mixture in the detonation chamber to generate rotating detonation waves within the detonation chamber;
• and
• controlling, by an engine controller, during operation of the rotating detonation combustor from a first power operating state to a second power operating state, different from the first power operating state, a flow of the auxiliary gas through the auxiliary gas injection port into one of the air inlet to mix with the flow of the air within the air inlet to control a discharge coefficient of the air inlet, or into the detonation chamber to mix with the fuel-air mixture within the detonation chamber to control a discharge coefficient of the detonation chamber, and to control an operating mode of the rotating detonation combustor.