Engine with rotating detonation combustion system

An engine, comprising:

• a longitudinal wall extended along a lengthwise direction, wherein the longitudinal wall defines a gas flowpath of the engine;
• an inner wall assembly extended from the longitudinal wall into the gas flowpath, wherein the inner wall assembly defines a rotating detonation combustion region in a first portion of the gas flowpath upstream of the inner wall assembly and adjacent to the longitudinal wall along the lengthwise direction and extending inward a depth from the longitudinal wall, a second portion of the gas flowpath being surrounded by the rotating detonation combustion region and extending in the lengthwise direction from upstream of the rotating detonation combustion region to downstream of the rotating detonation combustion region into an additional combustion region downstream of the rotating detonation combustion region,
• wherein the inner wall assembly comprises (a) an upstream face extended from the longitudinal wall into the gas flowpath adjacent to the rotating detonation combustion region, and (b) a downstream face extending at least partially along the lengthwise direction from an inward-most end of the upstream face to the longitudinal wall downstream of the inward-most end of the upstream face, wherein at least a portion of the upstream face extends downstream of the inward-most end of the upstream face, and wherein the upstream face provides a sheltered cavity at the rotating detonation combustion region at which a detonation wave propagates;
• a first fuel injector providing a first flow of fuel to the rotating detonation combustion region, and a second fuel injector providing a second flow of fuel through the downstream face to the additional downstream combustion region, which is positioned adjacent the downstream face and downstream of the rotating detonation combustion region,
• wherein the longitudinal wall further defines a combustion section at which the inner wall assembly is disposed and in which the rotation detonation combustion region and additional combustion region are located, and wherein the longitudinal wall further defines an exhaust nozzle distinct from and downstream of the combustion section in serial flow arrangement;
• and
• an inlet section upstream of the combustion section in serial flow arrangement, wherein the longitudinal wall defines a contour at the inlet section to provide a subsonic flow of oxidizer to the rotating detonation combustion region.