Rotating detonation engines are provided with various improvements pertaining to performance and reliability. Improvements pertain to, for example, a fluidic valve/premixing chamber, injection/swirl, flow control and turning, ignition, and cooling.

An engine that uses detonation for generating energy includes a housing; an inlet configured to inject a fuel mixture into an ignition region of the housing, the inlet being attached to the housing; an ignitor located in the ignition region and configured to ignite the fuel mixture; a deflagration to detonation, DDT, region in fluid communication and downstream from the ignition region; a pair of electrodes located in the DDT region and configured to apply nanosecond repetitive voltage pulses to the DDT region; and a detonation region, within the housing, in fluid communication and downstream from the DDT region. The nanosecond repetitive voltage pulses generate a non-thermal plasma that transition a combustion front propagation through the housing from a deflagration mode to a detonation mode.

An engine that uses detonation for generating energy includes a housing; an inlet configured to inject a fuel mixture into an ignition region of the housing, the inlet being attached to the housing; an ignitor located in the ignition region and configured to ignite the fuel mixture; a deflagration to detonation, DDT, region in fluid communication and downstream from the ignition region; a pair of electrodes located in the DDT region and configured to apply nanosecond repetitive voltage pulses to the DDT region; and a detonation region, within the housing, in fluid communication and downstream from the DDT region. The nanosecond repetitive voltage pulses generate a non-thermal plasma that transition a combustion front propagation through the housing from a deflagration mode to a detonation mode.

A pulse combustor system for efficiently operating a pulse combustor. The pulse combustor system includes the pulse combustor and a duct. The pulse combustor has a combustion chamber defining an internal space, a conduit having a first end in fluid communication with the internal space and a second end in fluid communication with an environment outside of the pulse combustor system, and a fuel injector configured to inject fuel into the internal space of the combustion chamber. The duct has two openings, with one opening disposed adjacent to the second end of the conduit. The pulse combustor system has an average operating frequency, and the duct has a length that is about one quarter of a wavelength corresponding to the average operating frequency. The pulse combustor and the duct each has a central longitudinal axis, and the two axes are substantially aligned.

An annular combustion chamber of the continuous detonation wave type enabling a mixture of a fuel and an oxidizer injected in an axial direction F to be used to deliver continuous production of hot gas from detonation waves, the combustion chamber including electrodes powered by an electricity generator and between which NRP electric discharges are generated, the combustion chamber including at the upstream ends of its outer and inner walls, a plurality of electrode pairs angularly distributed in two concentric rings, the electrodes of a pair each belonging to a different ring and being in radial alignment, and the electricity generator being configured to power at least one electrode pair to generate at least one discharge zone, and to power sequentially each of the electrode pairs following to the electrode pair and enable a detonation wave to travel around the annular combustion chamber.

An annular combustion chamber of the continuous detonation wave type enabling a mixture of a fuel and an oxidizer injected in an axial direction F to be used to deliver continuous production of hot gas from detonation waves, the combustion chamber including electrodes powered by an electricity generator and between which NRP electric discharges are generated, the combustion chamber including at the upstream ends of its outer and inner walls, a plurality of electrode pairs angularly distributed in two concentric rings, the electrodes of a pair each belonging to a different ring and being in radial alignment, and the electricity generator being configured to power at least one electrode pair to generate at least one discharge zone, and to power sequentially each of the electrode pairs following to the electrode pair and enable a detonation wave to travel around the annular combustion chamber.

A pulse combustor system for efficiently operating a pulse combustor. The pulse combustor system includes the pulse combustor and a duct. The pulse combustor has a combustion chamber defining an internal space, a conduit having a first end in fluid communication with the internal space and a second end in fluid communication with an environment outside of the pulse combustor system, and a fuel injector configured to inject fuel into the internal space of the combustion chamber. The duct has two openings, with one opening disposed adjacent to the second end of the conduit. The pulse combustor system has an average operating frequency, and the duct has a length that is about one quarter of a wavelength corresponding to the average operating frequency. The pulse combustor and the duct each has a central longitudinal axis, and the two axes are substantially aligned.

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 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.

Increased efficiency and reliability is achieved in an engine with a combustion chamber structured as detonation resonator with an outlet to an exhaust nozzle. The resonator is formed as an aspherical reflector symmetrical with respect to the engine axis. The engine uses gaseous fuels and a gaseous oxidizer in a single stage combustion process. A pyrolyzing chamber for hydrocarbon fuel. Pyrolizing is achieved by contact of fuel flow with heated back side of the reflector. A mixture of fuel and oxidizer is supplied into the combustion chamber through an annular supersonic injection system. To initiate detonation, these engines may have a detonation initiator formed as a tube plugged at the distal end and open at the end inserted into the combustion chamber and located along the axis of the engine. Detonation products ejected through the exhaust nozzle create thrust that pushes the engine in the opposite direction.