Compliant walled combustion devices for producing mechanical and electrical energy

• US 7,485,978 B2
• Filed: 06/14/2007
• Issued: 02/03/2009
• Est. Priority Date: 05/26/2004
• Status: Expired due to Fees

• Current Assignee: SRI International, Inc.
• Original Assignee: SRI International, Inc.
• Inventors: Pelrine, Ronald E., Prahlad, Harsha, Heim, Jonathan, Stanford, Scott E., Kornbluh, Roy D., Oh, Seajin
• Primary Examiner(s): GONZALEZ, JULIO CESAR
• Application Number:
  US11/763,148
• Publication Number:
  US 20080093849A1
• Time in Patent Office: 600 Days
• Field of Search: 290/1.R, 290/2, 290/1.A, 123/195.R, 310/363, 310/307, 310/339, 310/328
• US Class Current: 290/1.00R
• CPC Class Codes: F02B 75/36 Engines with parts of combustion- or working-chamber walls resiliently yielding under pressure

Abstract

Combustion devices described herein comprise a compliant combustion chamber wall or segment. The compliant segment deforms during combustion in the combustion chamber. Some devices may include a compliant wall configured to stretch responsive to pressure generated by combustion of a fuel in the combustion chamber. A coupling portion translates deformation of the compliant segment or wall into mechanical output. One or more ports are configured to inlet an oxygen source and fuel into the combustion chamber and to outlet exhaust gases from the combustion chamber.

Claims

1. A method for producing mechanical energy and electrical energy from a fuel, the method comprising:

providing a fuel and an oxygen source into a combustion chamber;

combusting the fuel in the combustion chamber;

stretching a compliant segment of a wall using pressure generated in the combustion;

translating mechanical energy produced in the combustion to a mechanical output that does work;

applying an electric field to a generator that is configured to generate the electrical energy using mechanical energy produced in the combustion, wherein the electrical field is applied before the compliant portion contracts from a stretched position, wherein the electrical field slows contraction of the compliant segment from a stretched position; and

generating electrical energy using mechanical energy produced in the combustion.

2. The method of claim 1 wherein the generator is also configured to operate as an actuator.

3. The method of claim 2 further comprising applying the electrical field to the actuator before combustion is complete and the electric field increases the mechanical output.

4. The method of claim 1 further comprising applying the electrical field to the actuator at top dead center of the combustion to oppose contraction forces produced in the stretch.

5. The method of claim 1 further comprising sensing position of the stretching compliant segment using the generator.

6. The method of claim 1 wherein the generator attaches to the compliant segment.

7. The method of claim 1 further comprising constraining an outer portion of the compliant segment.

8. The method of claim 1 further comprising igniting the fuel using electrical energy produced by the generator.

9. A combustion cycle for producing mechanical energy and electrical energy from a fuel, the cycle comprising:

providing a fuel and an oxygen source into a combustion chamber;

combusting the fuel in the combustion chamber;

stretching a compliant segment of a wall using pressure generated in the combustion;

translating mechanical energy produced in the combustion to a mechanical output that does work;

generating electrical energy using a generator and elastic return of the stretched compliant segment, wherein the generator is also configured to operate as an actuator; and

applying an electrical field to the actuator before combustion is complete and the electric field increases the mechanical output.

10. The combustion cycle of claim 9 further comprising at least partially exhausting combustion products using elastic return of the stretched compliant segment.

11. The combustion cycle of claim 9 further comprising applying an electric field to a generator that is configured to generate the electrical energy using mechanical energy produced in the combustion.

12. The combustion cycle of claim 11 wherein the electrical field is applied before the compliant portion contracts from a stretched position.

13. The combustion cycle of claim 12 wherein the electrical field slows contraction of the compliant segment from the stretched position.

14. The combustion cycle of claim 11 further comprising applying the electrical field to the actuator at top dead center of the combustion to oppose contraction forces produced in the stretch.

15. The combustion cycle of claim 9 further comprising igniting the fuel using a portion of the electrical energy.

16. A method for producing mechanical energy and electrical energy from a fuel, the method comprising:

providing a fuel and an oxygen source into a combustion chamber;

combusting the fuel in the combustion chamber;

stretching a compliant segment of a wall using pressure generated in the combustion;

translating mechanical energy produced in the combustion to a mechanical output that does work;

applying an electric field to a generator that is configured to generate the electrical energy using mechanical energy produced in a previous combustion in the combustion chamber,

wherein the generator is also configured to operate as an actuator, and the electrical field is applied to the actuator before combustion is complete and the electric field increases the mechanical output; and

generating electrical energy using mechanical energy produced in the combustion.

17. The combustion cycle of claim 16 wherein the generator attaches to the compliant segment.

18. The combustion cycle of claim 16 wherein the generator is also configured to operate as an actuator and the electric field increases the mechanical output.

19. A combustion cycle for producing mechanical energy and electrical energy from a fuel, the cycle comprising:

providing a fuel and an oxygen source into a combustion chamber;

combusting the fuel in the combustion chamber;

stretching a compliant segment of a wall using pressure generated in the combustion;

translating mechanical energy produced in the combustion to a mechanical output that does work;

applying an electric field to a generator that is configured to generate the electrical energy using mechanical energy produced in the combustion,

wherein the electrical field is applied before the compliant portion contracts from a stretched position, and

wherein the electrical field slows contraction of the compliant segment from the stretched position; and

generating electrical energy using elastic return of the stretched compliant segment.