A combustor for a rotating detonation engine includes an outer tapered wall extending along an axis; an inner tapered wall extending along the axis, wherein the inner tapered wall is positioned within the outer tapered wall to define an annular combustion chamber having an annular gap between the outer tapered wall and the inner tapered wall, wherein the outer tapered wall is moveable relative to the inner tapered wall along the axis, and wherein movement of the outer tapered wall relative to the inner tapered wall changes the annular gap of the annular combustion chamber. Obstacles can be positioned on either or both of inner and outer wall to enhance turbulence within the combustion chamber.

A combustor for a rotating detonation engine includes a radially outer wall extending along an axis (A); a radially inner wall extending along the axis (A), wherein the radially inner wall is positioned within the radially outer wall to define an annular detonation chamber having an inlet for fuel and oxidant and an outlet; a first passage for feeding at least one of the fuel and the oxidant along a first passage axis (a.sub.1) to the inlet; a second passage for feeding at least one of the fuel and the oxidant along a second passage axis (a.sub.2) to the inlet, wherein the second passage axis is arranged at an angle (α) relative to the first passage axis whereby mixing of flow from the first passage and the second passage is induced.

A constant volume combustion system includes at least one combustion chamber having at least one admission port and an exhaust port. The system also includes at least one elastically deformable tongue made of ceramic matrix composite material forming an air admission valve, the tongue being present inside the chamber and being positioned facing the admission port, the tongue having a first end that is stationary relative to an inside wall of the chamber and a second end, opposite from the first end, the second end being free and movable relative to the inside wall.

The present invention is a turbofan propulsion system, based on a tangential gas turbine that is structurally a part of the propulsion system's centrifugal compressor, wherein the gas turbine's combustion chambers with nozzles are placed to rotate around a larger radius circle at a supersonic circumferential speed, and the fan blades are placed to rotate around a smaller radius circle at a subsonic circumferential speed, therefore increasing the efficiency of the propulsion system.

A detonation engine can detonate a mixture of fuel and oxidizer within a cylindrical detonation region to produce work. The detonation engine can have a first and a second inlet having ends fluidly connected from tanks to the detonation engine. The first and second inlets can be aligned along a common axis. The inlets can be connected to nozzles and a separator can be positioned between the nozzles and along the common axis.

A detonation engine can detonate a mixture of fuel and oxidizer within a cylindrical detonation region to produce work. The detonation engine can have a first and a second inlet having ends fluidly connected from tanks to the detonation engine. The first and second inlets can be aligned along a common axis. The inlets can be connected to nozzles and a separator can be positioned between the nozzles and along the common axis.

A rotating detonation combustion (RDC) system is provided. The RDC includes a first outer wall and a second outer wall each extended around a centerline axis, and a detonation chamber formed radially inward of the second outer wall. A fuel passage extended between the first outer wall and the second outer wall, the fuel passage including a first inlet opening proximate to the aft end through which a flow of fuel is received into the fuel passage. The flow of fuel is provided through the fuel passage from the aft end to the forward end of the RDC system and to the detonation chamber.

A rotating detonation combustion (RDC) system is provided. The RDC includes a first outer wall and a second outer wall each extended around a centerline axis, and a detonation chamber formed radially inward of the second outer wall. A fuel passage extended between the first outer wall and the second outer wall, the fuel passage including a first inlet opening proximate to the aft end through which a flow of fuel is received into the fuel passage. The flow of fuel is provided through the fuel passage from the aft end to the forward end of the RDC system and to the detonation chamber.

A tuned cavity rotating detonation combustion system includes a an annular chamber having an inlet and an outlet; a valve plate at the inlet of the annular chamber and comprising a plurality of openings spaced circumferentially around the inlet; a plurality of tubes each having an open end in communication with a corresponding opening of the valve plate and a closed end forming a tuned cavity, and a first opening between the open end and the closed end for injection of air; and a plurality of fuel injectors corresponding to the plurality of tubes, each fuel injector being configured to inject fuel into the tube between the first opening and the open end. Each of the tuned cavities has a length sized to resonate at a same frequency as a continuous detonation frequency of at least one detonation wave in the annular chamber. Alternately, or additionally, a plurality of flame arresters corresponding to the plurality of tubes are configured to arrest the at least one detonation wave generated in the detonation chamber from travelling into the tube.

A compound engine assembly with at least one rotary internal combustion engine, an impulse turbine, and an exhaust pipe for each internal combustion engine providing fluid communication between the exhaust port of the respective internal combustion engine and the flow path of the turbine. Each exhaust pipe terminates in a nozzle. For each exhaust pipe, a ratio Vp/Vd between the pipe volume Vp and the displacement volume Vd of the respective internal combustion engine is at most 1.5. A minimum value of a cross-sectional area of each exhaust pipe is defined at the nozzle. In one embodiment, a ratio An/Ae between the minimum cross-sectional area An and the cross-sectional area Ae of the exhaust port of the respective internal combustion engine is at least 0.2. A method of compounding at least one rotary engine is also discussed.