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.

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.

An inlet manifold for a multi-tube pulse detonation engine includes a vaneless diffuser disposed in a first zone to collect an air discharged from a compressor; a vaned diffuser including a plurality of guide vanes disposed in a second zone to slow the air from the compressor; a plenum disposed in a third zone located next to second zone to provide the air from the compressor to chambers; and a splitter disposed in a fourth zone to split the air from the compressor into an airflow required by each pulse detonation tube for detonation.

An inlet manifold for a multi-tube pulse detonation engine includes a vaneless diffuser disposed in a first zone to collect an air discharged from a compressor; a vaned diffuser including a plurality of guide vanes disposed in a second zone to slow the air from the compressor; a plenum disposed in a third zone located next to second zone to provide the air from the compressor to chambers; and a splitter disposed in a fourth zone to split the air from the compressor into an airflow required by each pulse detonation tube for detonation.

An example system can include a radio-frequency power source and a resonator. The resonator can be configured to be electromagnetically coupled to the radio-frequency power source and can have a resonant wavelength. The resonator can include: a first conductor, a second conductor, and a dielectric between the first conductor and the second conductor. The resonator can also be configured such that, when the resonator is excited by the radio-frequency power source with a signal having a wavelength proximate to an odd-integer multiple of one-quarter of the resonant wavelength, the resonator provides at least one of a plasma corona or electromagnetic waves. The system can also include a fuel conduit configured to couple to a fuel source and having one or more outlets for expelling fuel, where at least a portion of the fuel conduit is arranged proximate to the dielectric.

An example system and corresponding method includes a power-generation turbine combustor and a resonator. The combustor includes (i) a combustion zone, (ii) one or more fuel inlets for introducing fuel into the combustion zone for combustion, and (iii) one or more fins protruding into the combustion zone and configured to guide combustion of the fuel along a flame path. The resonator can have a resonant wavelength and can provide a plasma corona in the combustion zone when excited with a signal having a wavelength proximate to an odd-integer multiple of one-quarter () of the resonant wavelength. A radio-frequency power source can excite the resonator with the signal so as to provide the plasma corona in the combustion zone and cause combustion of the fuel along the flame path.

An example system and corresponding method includes a jet engine combustor and a plurality of resonators. The combustor includes (i) a combustion zone, (ii) one or more fuel inlets for introducing fuel into the combustion zone for combustion, and (iii) one or more fins protruding into the combustion zone and configured to guide combustion of the fuel along a flame path. The resonators can each have a respective resonant wavelength and can each provide a respective plasma corona in the combustion zone when excited with a respective signal having a wavelength proximate to an odd-integer multiple of one-quarter () of the respective resonant wavelength. A radio-frequency power source can excite the resonators with the respective signals so as to provide the respective plasma coronas in the combustion zone and cause combustion of the fuel along the flame path.