A rotating detonation combustor includes a nozzle coupled to the combustor body at or near the exhaust opening to choke the exhaust opening. A rotating detonation combustor may include a diverting plate positioned radially inward of the inlet annulus and inlet channels for diverting flow of a mixture in an axial direction. A rotating detonation combustor may include a combustor body including an outer shell at least partially defining a detonation combustion chamber and extending axially from a base toward an exhaust opening of the detonation combustion chamber. The base defines a passageway in fluid communication with the detonation combustion chamber and includes an inlet annulus for axially directing a second fluid into the passageway and a plurality of inlet channels for radially directing a third fluid into at least one of the passageway or the detonation combustion chamber, and the detonation combustion chamber is free of any inner body.