Jet engine with plasma-assisted combustion

Patent metadata

Field	Value
Publication number	US-11725586-B2
Application number	US-201916517090-A
Country	US
Kind code	B2
Filing date	Jul 19, 2019
Priority date	Dec 20, 2017
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

An example system and corresponding method can include a combustion chamber of jet engine, a radio-frequency power source, and a resonator. The combustion chamber can include a liner defining a combustion zone, and include a fuel inlet configured to introduce fuel into the combustion zone. The resonator can have a resonant wavelength and include: a first conductor, a second conductor, a dielectric, and an electrode coupled to the first conductor. The resonator can 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 (¼) of the resonant wavelength, the resonator provides a plasma corona in the combustion zone. The controller can be configured to cause the radio-frequency power source to excite the resonator with the signal so as to provide the plasma corona.

First claim

What is claimed is:

1. A system, comprising:
a combustion chamber of a jet engine, the combustion chamber including a liner defining a combustion zone;
a radio-frequency power source;
a coaxial resonator electromagnetically coupled to the radio-frequency power source and having a resonant wavelength, the coaxial resonator including (i) a first conductor, (ii) a second conductor, (iii) a base conductor at a proximal end of the coaxial resonator, (iv) a dielectric between the first conductor and the second conductor, and (vi) an electrode electromagnetically coupled to the first conductor, the electrode having a distal end disposed in the combustion zone, the electrode having at least one outlet, wherein the coaxial resonator is configured such that, when the coaxial resonator is excited by the radio-frequency power source with a signal having a wavelength proximate to an odd-integer multiple of one-quarter (¼) of the resonant wavelength, the coaxial resonator provides a plasma corona in the combustion zone;
an impedance sensor that measures an impedance of the coaxial resonator and provides an impedance measurement, the impedance sensor being electrically coupled to the first conductor and the second conductor of the coaxial resonator; and
a controller that receives the impedance measurement and which is configured to cause the radio-frequency power source to excite the coaxial resonator with the signal so as to provide the plasma corona and cause combustion of fuel, the controller being configured to: determine at least one parameter of the combustion chamber from the impedance measurement, the at least one parameter comprising at least one of a temperature within the combustion chamber, a pressure within the combustion chamber, and a chemical composition within the combustion chamber; and to adjust the radio-frequency power source and the plasma corona generated in the combustion chamber based at least in part on the at least one determined parameter.

2. The system of claim 1 , further comprising a fuel conduit oriented so as to direct at least a portion of the fuel toward the electrode.

3. The system of claim 2 , further comprising a fuel tank configured to supply the fuel to the fuel conduit.

4. The system of claim 3 , further comprising a fuel pump that transfers the fuel from the fuel tank to the fuel conduit.

5. The system of claim 4 , wherein a longitudinal axis of the first conductor is oblique to a longitudinal axis of the combustion chamber, with a distal end of the first conductor disposed towards a distal end of the combustion chamber.

6. The system of claim 4 , wherein a longitudinal axis of the first conductor is perpendicular to a longitudinal axis of the combustion chamber.

7. The system of claim 1 , wherein the combustion chamber includes an outer casing through which the coaxial resonator extends.

8. The system of claim 1 , wherein the combustion chamber comprises a combustor selected from the group consisting of an annular combustor, a can combustor, and a can-annular combustor.

9. The system of claim 1 , further comprising a direct-current power source configured to provide a bias signal between the first conductor and the second conductor.

10. The system of claim 1 , wherein the impedance sensor is integrated into the controller.

11. The system of claim 1 , further comprising a fuel conduit that is defined within the first conductor, and the distal end of the electrode extending beyond an end of the coaxial resonator.

12. A method comprising:
introducing fuel through a fuel conduit of a coaxial resonator into a combustion zone of a combustion chamber of a jet engine;
exciting, by a radio-frequency power source, the coaxial resonator with a signal having a wavelength proximate to an odd-integer multiple of one-quarter (¼) of a resonant wavelength of the coaxial resonator, the coaxial resonator including (i) a first conductor, (ii) a second conductor, (iii) a base conductor at a proximal end of the coaxial resonator, (iv) a dielectric between the first conductor and the second conductor, and (v) an electrode electromagnetically coupled to the first conductor, the electrode having a distal end disposed within the combustion zone;
in response to exciting the coaxial resonator, providing a plasma corona in the combustion zone thereby causing combustion of the fuel; and
measuring an impedance of the coaxial resonator with an impedance sensor that is electrically coupled to the coaxial resonator
determining at least one parameter of the combustion chamber from the impedance, the at least one parameter comprising at least one of a temperature within the combustion chamber, a pressure within the combustion chamber, and a chemical composition within the combustion chamber
adjusting the radio-frequency power source based at least in part on the at least one parameter, wherein the adjustment of the radio-frequency power source modifies the plasma corona generated in the combustion zone.

13. The method of claim 12 , wherein introducing the fuel comprises directing a portion of the fuel towards the electrode.

14. The method of claim 13 , wherein introducing the fuel comprises using a fuel pump to transfer the fuel from a fuel tank to the fuel conduit.

15. The method of claim 12 , wherein a longitudinal axis of the first conductor is oblique to a longitudinal axis of the combustion chamber, with a distal end of the first conductor being disposed towards a distal end of the combustion chamber.

16. The method of claim 12 , wherein a longitudinal axis of the first conductor is perpendicular to a longitudinal axis of the combustion chamber.

17. The method of claim 12 , further comprising compressing air using a compressor of the jet engine, thereby causing compressed air to enter the combustion zone.

18. The method of claim 12 , further comprising causing a direct current power source to provide a bias signal between the first conductor and the second conductor.

19. The method of claim 12 , wherein the fuel conduit is defined within the first conductor, and the distal end of the electrode extending beyond an end of the coaxial resonator, wherein the fuel conduits shields the fuel from interacting with electromagnetic radiation in the coaxial resonator.

Assignees

• West Virginia Univ Board Of Governors On Behalf Of West Virginia Univ

Inventors

• Lowery Andrew D
• Smith James E

Classifications

• F02C7/266 Primary

  Electric (sparking plugs H01T) · CPC title

• F23R3/002

  Wall structures (F23R3/02 and F23R3/007 take precedence) · CPC title

• F23R3/28

  characterised by the fuel supply (burners F23D) · CPC title

• H01P7/04

  Coaxial resonators · CPC title

• H01P7/06

  Cavity resonators · CPC title