Embodiments of the present disclosure include an injection system. The injection system includes a Resonance Enhanced Microjet (REM) nozzle. The REM nozzles includes a REM nozzle block, the REM nozzle block having an inlet formed in a top and an outlet formed in a bottom, the inlet and outlet being fluid coupled together. The REM nozzle also includes one or more micronozzles positioned about the outlet, the one or more micronozzles having an outlet and being positioned at an angle relative to the bottom. Additionally, the REM nozzle includes an inlet conduit coupled to the REM nozzle block, the inlet conduit being fluidly coupled to the one or more micronozzles. The injection system also includes a source arranged proximate the top, the source directing a source jet of fluid into the inlet. The injection system includes a fuel supply fluidly coupled to the inlet conduit. Such a system can inject a fuel entrained in an oxidizer pulsing at very high-frequency. These pulsed fuel-oxidizer streams can be injected to a high-velocity fluid stream which allows better mixing of fuel and oxidizer at high speed.

A pulse combustor system for reducing noise and/or vibration levels. The system includes a pulse combustor including a combustion chamber, an inlet pipe, an exhaust pipe, and a first fuel injector for injecting fuel into the combustion chamber. The pulse combustor has a fundamental oscillation mode and one or more additional oscillation modes. The system includes at least one pressure sensor for measuring a pressure inside the fuel combustor and/or a at least one fluid velocity sensor for measuring fluid velocity at the inlet pipe or at the exhaust pipe. A controller adjusts a rate of fuel supply to the pulse combustor if the measured pressure and/or the measured velocity is above a predetermined threshold value to reduce excitation of the one or more additional oscillation modes.

A combustor for a detonation engine includes a radially outer wall extending along an axis; a radially inner wall extending along the axis, wherein the radially inner wall is positioned at least partially within the radially outer wall to define an annular detonation chamber having an inlet for fuel and oxidant and an outlet; a cooling flow passage defined along at least one of the radially outer wall and the radially inner wall and comprising at least two axially spaced cooling flow passage sections, whereby a different cooling rate can be implemented in the at least two axially spaced cooling flow passage sections.

A combustor for a detonation engine includes a radially outer wall extending along an axis; a radially inner wall extending along the axis, wherein the radially inner wall is positioned at least partially within the radially outer wall to define an annular detonation chamber having an inlet for fuel and oxidant and an outlet; a cooling flow passage defined along at least one of the radially outer wall and the radially inner wall and comprising at least two axially spaced cooling flow passage sections, whereby a different cooling rate can be implemented in the at least two axially spaced cooling flow passage sections.

A flow-management system may comprise a center body impermeable to air. A conical surface of the center body may face forward. A blocking surface of the center body may be coaxial with the conical surface and may comprise an annular recess. An annular ring may be aft of the center body and fluidly coupled with the blocking surface. A tube may encase the center body and annular ring. The annular ring may comprise an air-foil shape to direct a pulse to the blocking surface. The blocking surface may comprise a central peak and a circular ridge separated by the annular recess.

A flow-management system may comprise a center body impermeable to air. A conical surface of the center body may face forward. A blocking surface of the center body may be coaxial with the conical surface and may comprise an annular recess. An annular ring may be aft of the center body and fluidly coupled with the blocking surface. A tube may encase the center body and annular ring. The annular ring may comprise an air-foil shape to direct a pulse to the blocking surface. The blocking surface may comprise a central peak and a circular ridge separated by the annular recess.

The present invention relates to methods, apparatuses, and systems for controlling the density of a fluid near a functional object in order to improve one or more relevant performance metrics. In certain embodiments, the present invention relates to forming a low density region near the object utilizing a directed energy deposition device to deposit energy along one or more paths in the fluid. In certain embodiments, the present invention relates to synchronizing energy deposition with one or more parameters impacting the functional performance of the object.

A Brayton cycle engine and method for operation. The engine includes an inner wall assembly and an upstream wall assembly each extended from a longitudinal wall into a gas flowpath. An actuator adjusts a depth of the detonation combustion region into the gas flowpath between the inner wall assembly and the upstream wall assembly. The engine flows an oxidizer through the gas flowpath and the inner wall captures a portion of the oxidizer. The engine further adjusts the captured flow of oxidizer via the upstream wall and flows a first flow of fuel to the captured flow of oxidizer to produce rotating detonation gases. The engine flows the detonation gases downstream and to mix with the flow of oxidizer, and flows and burns a second flow of fuel to the detonation gases/oxidizer mixture to produce thrust.

A Brayton cycle engine and method for operation. The engine includes an inner wall assembly and an upstream wall assembly each extended from a longitudinal wall into a gas flowpath. An actuator adjusts a depth of the detonation combustion region into the gas flowpath between the inner wall assembly and the upstream wall assembly. The engine flows an oxidizer through the gas flowpath and the inner wall captures a portion of the oxidizer. The engine further adjusts the captured flow of oxidizer via the upstream wall and flows a first flow of fuel to the captured flow of oxidizer to produce rotating detonation gases. The engine flows the detonation gases downstream and to mix with the flow of oxidizer, and flows and burns a second flow of fuel to the detonation gases/oxidizer mixture to produce thrust.

The present disclosure is directed to a method of operating a propulsion system at an approximately constant detonation cell quantity in the combustion chamber of a detonation combustion system. The propulsion system defines an inlet section upstream of the rotating detonation combustion system and an exhaust section downstream of the rotating detonation combustion system. The method includes providing an outer wall and an inner wall together defining an annular gap and a combustion chamber length extended from a combustion chamber inlet proximate to the fuel-oxidizer mixing nozzle to a combustion chamber exit proximate to the exhaust section of the propulsion system, the annular gap and the combustion chamber length together defining a first volume at a first operating condition defining a lowest steady state pressure and temperature at the rotating detonation combustion system; providing a mixture of a fuel and an oxidizer to the combustion chamber via the fuel-oxidizer mixing nozzle; detonating the fuel and oxidizer mixture in the combustion chamber, wherein the detonation produces a detonation cell size; and adjusting the volume of the combustion chamber via articulating one or more of the outer wall, the inner wall, and the fuel-oxidizer mixing nozzle such that one or more of the annular gap and the combustion chamber length is changed based on one or more operating conditions.