Abstract: Embodiments disclosed herein include flame holders that may provide recirculated fuel flow therethrough, combustion systems that include such flame holders, and related methods. A fuel and/or fuel-oxidant mixture may pass through one or more openings in the flame holder and, after combustion, the resulting flame may be held at or near a surface of the flame holder including in the one or more openings. Generally, the configuration of the flame holders disclosed herein (e.g., the one or more openings of the flame holders) may recirculate or regulate (e.g., decrease and/or increase) the flow of fuel and/or oxidant therethrough, at least limit flame flashback, improve fuel/oxidant mixing, increase flame stability, regulate where the flame is located in the flame holder, improve the operational stability window of the combustion system, or combinations of the foregoing.

Abstract: An inertial electrode launcher may be configured to project charged particles or a voltage comprising an inertial electrode proximate a flame or combustion gas produced by the flame.

Abstract: A combustion system such as a furnace or boiler includes a perforated reaction holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).

Abstract: A perforated flame holder and burner including a perforated flame holder provides reduced oxides of nitrogen (NOx) during operation. The perforated flame holder includes a pattern of elongated apertures extending between a proximal and a distal surface of the flame holder relative to a fuel nozzle. The perforated flame holder can provide a significantly reduced flame height while maintaining heat output from the burner.

Abstract: Systems and method for active control of stationary vortices for aerodynamic structures are disclosed herein. In one embodiment, a method for active control of vortices over a solid surface includes: generating vortices proximate to the solid surface; sensing locations of vortices by printed skin sensors; and maintaining the vortices in their fixed spanwise positions with respect to the solid surface by actuation of printed skin actuators.

Abstract: A combustion system such as a furnace or boiler includes a perforated reaction holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).

Abstract: An electrically stabilized burner is configured to support a combustion reaction such as a combustion reaction substantially at a selected fuel dilution and with a mixing rate selected to maximize the reaction rate without quenching the combustion reaction.

Abstract: According to embodiments, a co-fired or multiple fuel combustion system is configured to apply an electric field to a combustion region corresponding to a second fuel that normally suffers from poor combustion and/or high sooting. Application of an AC voltage to the combustion region was found to increase the extent of combustion and significantly reduce soot evolved from the second fuel.

Abstract: An electrically stabilized burner is configured to support a combustion reaction such as a combustion reaction substantially at a selected fuel dilution and with a mixing rate selected to maximize the reaction rate without quenching the combustion reaction.

Abstract: According to embodiments, a co-fired or multiple fuel combustion system is configured to apply an electric field to a combustion region corresponding to a second fuel that normally suffers from poor combustion and/or high sooting. Application of an AC voltage to the combustion region was found to increase the extent of combustion and significantly reduce soot evolved from the second fuel.

Abstract: Continuous rotating detonation engines including an annular combustion chamber formed between substantially concentric inner and outer cylindrical shells. A plurality of ignition devices extend into the annular combustion chamber and can be positioned around a circumference of at least one of the inner and outer cylindrical shells. Each ignition device is operative to provide ignition energy to the combustion chamber upon respective activation thereof. A plurality of injection openings extend radially through at least one of the inner and outer cylindrical shells for fluid communication with the annular combustion chamber.

Abstract: A system is configured to apply a voltage, charge, and/or an electric field to a combustion reaction responsive to acoustic feedback from the combustion reaction.

Abstract: A fire tube boiler includes a perforated flame holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).

Abstract: A combustion system includes a combustion reaction holder that defines plurality of combustion channels and a fluid volume separate from the plurality of combustion channels. The combustion channels are collectively configured to hold a combustion reaction. Heat from the combustion reaction is transferred to a fluid disposed in the fluid volume.

Abstract: A combustion system such as a furnace or boiler includes a perforated reaction holder configured to hold a combustion reaction that produces very low oxides of nitrogen (NOx).

Abstract: A combustion system includes an electrically actuated flame location control mechanism.

Abstract: A supersonic compressor including a rotor to deliver a gas at supersonic conditions to a diffuser. The diffuser includes a plurality of aerodynamic ducts that have converging and diverging portions, for deceleration of gas to subsonic conditions and then for expansion of subsonic gas, to change kinetic energy of the gas to static pressure. The aerodynamic ducts include vortex generating structures for controlling boundary layer, and structures for changing the effective contraction ratio to enable starting even when the aerodynamic ducts are designed for high pressure ratios, and structures for boundary layer control. In an embodiment, aerodynamic ducts are provided having an aspect ratio of in excess of two to one, when viewed in cross-section orthogonal to flow direction at an entrance to the aerodynamic duct.

Abstract: In a combustion system, a charge source is configured to cooperate with a collection plate and a director conduit to cause at least one particle charge-to-mass classification to be reintroduced to a flame for further reaction.

Abstract: According to embodiments, a co-fired or multiple fuel combustion system is configured to apply an electric field to a combustion region corresponding to a second fuel that normally suffers from poor combustion and/or high sooting. Application of an AC voltage to the combustion region was found to increase the extent of combustion and significantly reduce soot evolved from the second fuel.

Abstract: A system is configured to apply a voltage, charge, and/or an electric field to a combustion reaction responsive to acoustic feedback from the combustion reaction.