Multi-mode combustion control for a rotating detonation combustion system

A combustion system, the combustion system defining an aft end at which gases exit and a forward end at which a flow of oxidizer enters, the combustion system comprising:

• an outer wall at least partially defining a combustion chamber;
• a deflagrative fuel circuit configured to provide a first flow of fuel to the combustion chamber;
• a detonation fuel circuit configured to provide a second flow of fuel to the combustion chamber;
• and
• a control valve positioned at one or more of the deflagrative fuel circuit or the detonation fuel circuit, the control valve configured to adjust a fuel split of a total flow fuel between the deflagrative fuel circuit and the detonation fuel circuit;
• and
• a controller configured to store instructions that, when executed, perform operations, the operations comprising:
• initializing combustion of a fuel/oxidizer mixture;
• determining whether conditions at the combustion system meet or exceed a first threshold operating parameter;
• transitioning to detonation combustion of the fuel/oxidizer mixture if conditions at the combustion system meet or exceed the first threshold operating parameter;
• during the transition to detonation combustion, sustaining detonation of the fuel/oxidizer mixture at the combustion system by adjusting a fuel flow through the deflagrative fuel circuit, wherein adjusting the fuel flow through the deflagrative fuel circuit comprises:
• maintaining or increasing the fuel flow through the deflagrative fuel circuit if the conditions at the combustion system do not meet or exceed the first threshold operating parameter;
• determining whether the conditions at the combustion system exceed a second threshold operating parameter;
• and
• decreasing the fuel flow through the deflagrative fuel circuit until the conditions at the combustion system do not exceed the second threshold operating parameter.

A heat engine, the heat engine comprising:

• a compressor section;
• an expansion section;
• a multi-mode combustion system positioned in serial flow arrangement between the compressor section and the expansion section, the multi-mode combustion system comprising:
• an outer wall at least partially defining a combustion chamber;
• a deflagrative fuel circuit configured to provide a first flow of fuel to the combustion chamber;
• a detonation fuel circuit configured to provide a second flow of fuel to the combustion chamber;
• and
• a control valve positioned at one or more of the deflagrative fuel circuit or the detonation fuel circuit, the control valve configured to adjust a fuel split of a total flow fuel between the deflagrative fuel circuit and the detonation fuel circuit;
• and
• a controller configured to store instructions that, when executed, perform operations, the operations comprising:
• initializing combustion of a fuel/oxidizer mixture;
• determining whether conditions at the multi-mode combustion system meet or exceed a first threshold operating parameter;
• transitioning to detonation combustion of the fuel/oxidizer mixture if conditions at the multi-mode combustion system meet or exceed the first threshold operating parameter;
• and
• during the transition to detonation combustion, sustaining detonation of the fuel/oxidizer mixture at the multi-mode combustion system by adjusting a fuel flow through the deflagrative fuel circuit, wherein adjusting the fuel flow through the deflagrative fuel circuit comprises:
• maintaining or increasing the fuel flow through the deflagrative fuel circuit if the conditions at the multi-mode combustion system do not meet or exceed the first threshold operating parameter;
• determining whether the conditions at the multi-mode combustion system exceed a second threshold operating parameter;
• and
• decreasing the fuel flow through the deflagrative fuel circuit until the conditions at the multi-mode combustion system do not exceed the second threshold operating parameter.