A method of controlling operation of a pressure gain combustor comprises: determining a fuel injector duty cycle and a combustion frequency that meets a target load set point and a target fill fraction of the combustor; determining a fuel supply pressure setting, a fuel injector timing setting and an ignition timing setting that achieves the determined fuel injector duty cycle and combustion frequency; and sending a fuel supply pressure control signal with the fuel supply pressure setting to a fuel pressurizing means of the combustor, a fuel injector control signal with the fuel injector timing setting to a fuel injector of the combustor, and an ignition timing control signal with the ignition timing setting to an ignition assembly of the combustor.

A method of controlling operation of a pressure gain combustor comprises: determining a fuel injector duty cycle and a combustion frequency that meets a target load set point and a target fill fraction of the combustor; determining a fuel supply pressure setting, a fuel injector timing setting and an ignition timing setting that achieves the determined fuel injector duty cycle and combustion frequency; and sending a fuel supply pressure control signal with the fuel supply pressure setting to a fuel pressurizing means of the combustor, a fuel injector control signal with the fuel injector timing setting to a fuel injector of the combustor, and an ignition timing control signal with the ignition timing setting to an ignition assembly of the combustor.

A Brayton cycle engine including an inner wall assembly defining a detonation combustion region upstream thereof extended from a longitudinal wall into a gas flowpath. An actuator adjusts a depth of the detonation combustion region into the gas flowpath. A method for operating the engine includes flowing an oxidizer through the gas flowpath; capturing a portion of the flow of oxidizer via the inner wall; flowing a first flow of fuel to the captured flow of oxidizer; producing a rotating detonation gases via a mixture of the first flow of fuel and the captured flow of oxidizer; flowing at least a portion of the detonation gases downstream to mix with the flow of oxidizer; flowing a second flow of fuel to the mixture of detonation gases and oxidizer; and burning the mixture of the second flow of fuel and the detonation gases/oxidizer mixture.

A Brayton cycle engine including a longitudinal wall extended along a lengthwise direction. The longitudinal wall defines a gas flowpath of the engine. An inner wall assembly is extended from the longitudinal wall into the gas flowpath. The inner wall assembly defines a detonation combustion region in the gas flowpath upstream of the inner wall assembly.

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 fuel detonation combustion pulse device includes a semispherical combustion chamber, a fuel supply system, a spark plug, a detonation accelerator, a hemispherical combustion chamber having a conic duct for transition to the detonation tube; a spark plug is mounted at the end wall of the sphere of the combustion chamber along its longitudinal axis, a fuel supply system is formed as a co-axial injector for fuel; an annular oxidant supply nozzle located perpendicular to the longitudinal axis of the device, and a detonation accelerator is shaped as a profiled stepped obstacle and is mounted in the combustion chamber conic duct for transition to the detonation tube being axial with it.

A device for the repeated production of explosions includes an explosion space, a feed conduit for feeding a flowable, explosive material, a discharge opening for the directed discharge of a gas pressure produced by the ignition of the explosive material in the explosion space, and a movable closure element for the partial or complete closure of the discharge opening. The device includes an exit nozzle with a nozzle entry area and a nozzle exit area, as well as an actuation device. The actuation device is adapted, after an opening of the discharge opening and an outflow of explosion gases through the exit nozzle, to adjust an area ratio between the nozzle entry area and the nozzle exit area. The area ratio at least approximately follows an ideal area ratio for the production of a maximal exit speed of the explosion gases, in dependence on the pressure in the explosion space.

A device for the repeated production of explosions includes an explosion space, a feed conduit for feeding a flowable, explosive material, a discharge opening for the directed discharge of a gas pressure produced by the ignition of the explosive material in the explosion space, and a movable closure element for the partial or complete closure of the discharge opening. The device includes an exit nozzle with a nozzle entry area and a nozzle exit area, as well as an actuation device. The actuation device is adapted, after an opening of the discharge opening and an outflow of explosion gases through the exit nozzle, to adjust an area ratio between the nozzle entry area and the nozzle exit area. The area ratio at least approximately follows an ideal area ratio for the production of a maximal exit speed of the explosion gases, in dependence on the pressure in the explosion space.

Methods of powering a heat engine with a remote lasers are disclosed, where the ambient air surrounding the engine is used as the working fluid. All methods include inputting the ambient air into the engine, absorbing laser optical radiation, turning it into heat, supplying the heat to the air, harvesting mechanical work from expanding air and releasing the air back into surrounding atmosphere.

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.