Fluid Powered Oscillator

Abstract

A method and device for converting fluidic kinetic energy into oscillatory mechanical motion is disclosed. A mechanical structure of finite stiffness is coupled to a fluid-dynamical control surface the thrust from which is oscillated in direction. The coupling thereby induces oscillations in the structure, the magnitude of which can be controlled by the degree of mechanical resonance between the oscillation rate of the fluidic thrusting and the structure's resonance frequency. The resulting mechanical energy can be converted into electrical energy using either piezo-electric or electromagnetic means.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The description is accompanied by drawings that are given by way of illustration only, and thus are not limitative of the present invention, and in which embodiments of the present invention are described. In the drawings:

FIG. 1 is a diagram illustrating the principle components of the invention;

FIG. 2 is a diagram of a method by which the oscillation of a mechanical structure may be induced by a fluid flow, in which one oscillates the direction of the fluidic forcing by varying the orientation of the control surface;

FIG. 3 is a diagram illustrating the motion of the preferred embodiment of the invention when viewed looking into the direction of the fluid flow;

FIG. 4 is a diagram of an alternative embodiment of the invention, in which active means consisting of a sensor, a controller, and an actuator are employed to oscillate the direction of the fluidic forcing;

FIG. 5 is diagram of the preferred embodiment of the invention, in which a piezo-electric layer—sandwiched between two, electrode layers—is used to convert the mechanical oscillation into electrical energy;

FIG. 6 is a diagram of an alternative embodiment of the invention, in which a capacitive structure, mounted parallel to the oscillation direction of the main structure, is used to convert the mechanical oscillation into electrical energy;

FIG. 7 is a diagram of an alternative embodiment of the invention, in which a capacitive structure, mounted perpendicular to the oscillation direction of the main structure, is used to convert the mechanical oscillation into electrical energy.

Claims

1. A method for transforming fluidic kinetic energy into electrical energy, which comprises in combination:(a) a mechanical structure of finite stiffness,(b) means for applying a force upon said structure,(c) means for coupling the fluidic kinetic energy with said forcing means,(d) means for oscillating the direction of said forcing means, and(e) means for converting said motion into electrical energy,whereby said electrical energy is generated.

2. The energy transformation method of claim 1 wherein said means for converting the oscillatory motion into electrical energy comprises: (a) means for creating an electromagnetic field about said structure, and(b) means for detecting variation in said electromagnetic field.

3. The means for converting oscillatory motion into electrical energy of claim 2 wherein said means for creating an electromagnetic field is a capacitive structure.

4. The means for converting oscillatory motion into electrical energy of claim 2 wherein said means for creating an electromagnetic field is an inductive structure.

5. The energy transformation method of claim 1 wherein said mechanical structure has a resonance frequency substantially equal to the frequency of the alternating current variations in the electrical grid.

6. The energy transformation method of claim 1 wherein said means for coupling the fluidic kinetic energy with said forcing means is an airfoil.

7. The energy transformation method of claim 1 wherein said means for oscillating the direction of said forcing means is an aerodynamic structure that applies an oscillating lateral thrust in response to steady fluid flows.

8. The energy transformation method of claim 1 wherein said means for oscillating the direction of said forcing means oscillates at the resonance frequency of the mechanical structure.

9. The energy transformation method of claim 1 wherein said means for oscillating the direction of said forcing means comprises: (a) means for sensing the mechanical motion of said structure; and (b) means for coupling said sensing means with said forcing means.

10. The energy transformation method of claim 1 wherein said means for converting the oscillatory motion into electrical energy is a piezoelectric structure.

11. A method for transforming fluidic kinetic energy into oscillatory mechanical motion, which comprises in combination: (a) a mechanical structure of finite stiffness,(b) means for applying a force upon said structure,(c) means for coupling the fluidic kinetic energy with said forcing means, and(d) means for oscillating the direction of said forcing means,whereby said fluidic kinetic energy is transduced into the oscillatory motion of said structure.

12. The energy transformation method of claim 11 wherein said means for coupling the fluidic kinetic energy with said forcing means is an airfoil.

13. The energy transformation method of claim 11 wherein said means for varying the direction of said forcing means is an aerodynamic structure that applies an oscillating lateral thrust in response to steady fluid flows.

14. The energy transformation method of claim 11 wherein said means for varying the direction of said forcing means oscillates at the resonance frequency of the mechanical structure.

15. The energy transformation method of claim 11 wherein said means for varying the direction of said forcing means comprises: (a) means for sensing the mechanical motion of said structure, and (b) means for coupling said sensing means with said forcing means.

16. A device for transforming fluidic kinetic energy into electrical energy, which comprises in combination: (a) a mechanical structure of finite stiffness,(b) a piezo-electric layer deposited on said structure,(c) means for measuring the voltage developed across said piezo-electric layer,(d) means for creating a force from said fluidic kinetic energy,(e) mechanical means for coupling said force-creation means with said structure, and(f) means for oscillating the direction of the force that results from said force-creation means,whereby said fluidic kinetic energy is transformed into electrical energy.

17. The transformation device of claim 16 wherein said means for creating a force from said fluidic kinetic energy is an airfoil.

18. The transformation device of claim 16 wherein said means for oscillating the direction of said force is an aerodynamic structure that applies an oscillating lateral thrust in response to steady fluid flows.

19. The transformation device of claim 16 wherein said means for oscillating the direction of said forcing means varies at the resonance frequency of the mechanical structure.

20. The transformation device of claim 16 wherein said means for oscillating the direction of said forcing means comprises: (a) means for sensing the mechanical motion of said structure, and (b) means for coupling said sensing means with said forcing means.