Example implementations relate to jet engines that include resonator-based diagnostics. An example implementation includes a jet engine. The jet engine includes a combustion chamber configured to house a combustion event of a fuel mixture. The jet engine also includes a resonator having a characteristic impedance and a resonant wavelength. The resonator includes a first conductor and a second conductor separated from one another by an interstitial space that is exposed to an environment of the combustion chamber. Further, the jet engine includes a controller communicatively coupled to the resonator and configured to perform operations. The operations include determining a characteristic of the resonator selected from the group consisting of the characteristic impedance and the resonant wavelength. The operations also include, based on the determined characteristic, determining a parameter of the combustion chamber.

An inductively coupled plasma device includes a rotary furnace tube and an inductively coupled plasma source. The rotary furnace tube has a first end, a second end and a longitudinal axis. In a first embodiment, the inductively coupled plasma source is disposed proximate to the first end of the rotary furnace tube and is aligned with the longitudinal axis of the rotary furnace such that the inductively coupled plasma source discharges a plasma into the rotary furnace tube. In a second embodiment, the inductively coupled plasma source is a ground electrode disposed within and aligned with the longitudinal axis of the rotary furnace tube, and a second electromagnetic radiation source disposed around or within the rotary furnace tube that generates a wave energy. The inductively coupled plasma source discharges a plasma within the rotary furnace tube.

An engine includes an inlet tube introducing air to a combustion process and a first plurality of fuel injectors disposed in the inlet tube and used for scram-jet engine operation. The engine includes a second plurality of fuel injectors used for ram-jet engine operation. The second plurality of fuel injectors is upstream from the first plurality of fuel injectors and is disposed in the inlet tube. The engine includes a combustor swirl zone downstream of and adjacent to the first plurality of fuel injectors.

An ignition system for a combustor of a gas turbine engine is disclosed. The ignition system may include an igniter operatively associated with the combustor, and an electrode operatively associated with the combustor and spaced from the igniter, wherein an electrical potential is created between the igniter and the electrode to produce an electric arc therebetween.

An embodiment of a torch igniter for a combustor of a gas turbine engine includes a combustion chamber oriented about an axis, a cap defining an axially upstream end of the combustion chamber, a tip defining the axially downstream end of the combustion chamber, an igniter wall extending from the cap to the tip and defining a radial extent of the combustion chamber, a structural wall coaxial with and surrounding the igniter wall, an outlet passage defined by the igniter wall within the tip, a glow plug housing configured to receive a glow plug and allow an innermost end of the glow plug to extend into the combustion chamber, and a cooling system. The cooling system includes an air inlet formed within an exterior of the structural wall, a cooling channel forming a flow path through the structural wall at the glow plug housing, and an air passage.

The present invention provides a plasma arc torch that can be used for lean combustion. The plasma arc torch includes a cylindrical vessel, an electrode housing connected to the first end of the cylindrical vessel such that a first electrode is (a) aligned with a longitudinal axis of the cylindrical vessel, and (b) extends into the cylindrical vessel, a linear actuator connected to the first electrode to adjust a position of the first electrode, a hollow electrode nozzle connected to the second end of the cylindrical vessel such that the center line of the hollow electrode nozzle is aligned with the longitudinal axis of the cylindrical vessel, and wherein the tangential inlet and the tangential outlet create a vortex within the cylindrical vessel, and the first electrode and the hollow electrode nozzle create a plasma that discharges through the hollow electrode nozzle.

A gas turbine includes a combustion chamber and a microwave source to produce microwave radiation. The gas turbine is arranged to guide the microwave radiation into a cavity of the combustion chamber. Due to the microwave radiation, in the cavity of the combustion chamber, combustion in the cavity may be supported and thus lean operation of the gas turbine is made possible.

A plasma injection module includes a fuel receiving end, a discharge end opposite the fuel receiving end, and an axial fluid pathway extending between the fuel receiving end and the discharge end. An insulator assembly defines a first portion of the axial fluid pathway proximate to the fuel receiving end. An injection tube assembly having a permanent magnet is positioned downstream of the insulator. A voltage input connection is arranged downstream of the insulator assembly and upstream of the injection tube assembly. The voltage input connection secures a voltage source to the injection tube to form a plasma filament within and adjacent to the axial fluid pathway. During operation a permanent magnet produces a magnetic field that interacts with the 10 plasma filament to rotate the plasma filament and increase an area of ignition between the plasma filament and the combustible material at the discharge end.

A plasma injection module includes a fuel receiving end, a discharge end opposite the fuel receiving end, and an axial fluid pathway extending between the fuel receiving end and the discharge end. An insulator assembly defines a first portion of the axial fluid pathway proximate to the fuel receiving end. An injection tube assembly having a permanent magnet is positioned downstream of the insulator. A voltage input connection is arranged downstream of the insulator assembly and upstream of the injection tube assembly. The voltage input connection secures a voltage source to the injection tube to form a plasma filament within and adjacent to the axial fluid pathway. During operation a permanent magnet produces a magnetic field that interacts with the plasma filament to rotate the plasma filament and increase an area of ignition between the plasma filament and the combustible material at the discharge end.