Wind power generator and velocimeter

• US 5,223,763 A
• Filed: 02/28/1991
• Issued: 06/29/1993
• Est. Priority Date: 02/28/1991
• Status: Expired due to Fees

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Chang, David B.
• Primary Examiner(s): Budd, Mark O.
• Assistant Examiner(s): Dougherty, Thomas M.
• Application Number:
  US07/661,977
• Time in Patent Office: 852 Days
• Field of Search: 73/861.22, 73/861.24, 73/861.23, 310/338, 310/339
• US Class Current: 310/339
• CPC Class Codes: H02N 2/185 using fluid streams

Abstract

An apparatus and method are disclosed for producing electrical power from wind flow. The apparatus includes a conduit (13) with a variably sloped wall (59) for channeling the wind flow along a predetermined path (23), a baffle (25) positioned in the path of the flow for forming vortices (27-33) in the flow, and a plurality of piezoelectric transducers (35-45) positioned in sequence, each positioned a predetermined distance from the other, in the path of the flow for producing electrical output signals in response to pressure applied by the vortices upon the transducers. The individual output signals are combined to produce an aggregate power output. The system also includes a frequency counter (61) responsive to the output signal of at least one transducer for determining wind velocity. The method employed by the system includes the steps of channeling the wind flow along a predetermined path, forming vortices in the flow by positioning a baffle in the path of the flow and by varying the slope of the wall (and hence, the flow) so that the Reynold'"'"'s Number representative of the flow is in the range from 40 to 300, conducive to formation of vortices, and positioning the transducers in the path of the vortices for producing electrical power in response to pressure from the vortices upon the transducers.

Claims

1. An electrical power generating apparatus comprising:

a conduit receptive of fluid flow for channeling the fluid flow along a predetermined pat wherein said conduit has a fluid flow input section and a flow region constructed to maintain laminar fluid flow;

baffle means disposed in said conduit in the path of said laminar fluid flow and shaped to form vortices in said fluid flow; and

a plurality of piezoelectric transducers disposed axially within said flow region in the path of said laminar fluid flow for producing an electrical signal in response to stress created in said transducers by said vortices, wherein a portion of said baffle means is cylindrically shaped, said portion having a predetermined diameter and a longitudinal axis disposed perpendicular to the predetermined path, and wherein said predetermined diameter is selected such that the Reynold'"'"'s number representative of fluid flow at the baffle is in the range from 40 to 300.

2. The apparatus as in claim 1 wherein said conduit means is cylindrically shaped, and has a first opening at one end and a second opening at an opposite end, the diameter of at least one of said openings being variable.

3. The apparatus as in claim 1 wherein said piezoelectric transducers are arranged in series in the direction of fluid flow, with adjacent transducers positioned a selected uniform distance from each other, enabling each vortex to impact successive transducers as it flows past each transducer in the series.

4. The apparatus as in claim 3 wherein output signals from the piezoelectric transducer means are produced in parallel, and added to produce an aggregate power output.

5. The apparatus as in claim 4 wherein said fluid is liquid.

6. The apparatus as in claim 4 wherein said fluid is a gas.

7. The apparatus as in claim 4 wherein said power is alternating current power.

8. The apparatus as in claim 5 wherein said liquid is water.

9. The apparatus as in claim 6 wherein said gas is air.

10. An apparatus for measuring the velocity of fluid flow comprising:

conduit means receptive of the fluid flow for channeling said fluid flow along a predetermined path;

a rod-like baffle disposed transversely in the path of said fluid flow, for forming a plurality of vortices in said fluid flow; and

a plurality of piezoelectric transducer means disposed in the path of said fluid flow periodic distances form said baffle and each other, said distances determined by the Reynold'"'"'s number associated with said baffle, said transducer means for producing successive output signals in response to said vortices, the frequency of the signals having a determinable relationship to the velocity of fluid flow.

13. The apparatus as in claim 10 including means connected to said piezoelectric transducer means for receiving said output signals, determining said frequency and calculating the velocity of fluid flow.

14. An apparatus as in claim 10 wherein said conduit means includes a conical fluid flow input end.

11. An electrical power generating apparatus comprising:

conduit means receptive of fluid flow for channeling said fluid flow along a predetermined path, wherein said conduit means includes a wall with a changeable slope for varying said fluid flow;

baffle means disposed in the path of said fluid flow and shaped to form vortices in said fluid flow; and

a plurality of piezoelectric transducer means disposed in the path of said fluid flow for producing an electrical signal in response to stress created in said transducer means by said vortices, wherein a portion of said baffle means is cylindrically shaped, said portion having a predetermined diameter and a longitudinal axis disposed perpendicular to the predetermined path, and wherein said predetermined diameter and said slope are selected such that the Reynold'"'"'s number representative of fluid flow at the baffle is in a range from 40 to 300.

12. The apparatus as in claim 11 wherein said conduit means includes a cone-shaped conduit portion.

15. An apparatus for measuring the velocity of fluid flow comprising:

elongated conduit means receptive of the fluid flow for channeling said fluid along a predetermined, axial path;

baffle means shaped, and disposed within said conduit means in the path of said fluid flow, for forming a vortex in said fluid flow; and

at least a first and a second piezoelectric transducer means, said first piezoelectric transducer means axially disposed a predetermined first distance from said baffle means, and said at lest two piezoelectric transducer means axially disposed a predetermined second distance form each other in the path of said fluid flow, said distances being determined by the Reynold'"'"'s number associated with said baffle means.

16. The apparatus as in claim 15 including a means connected to said at least first and second transducer means for receiving said first and second output signals and for determining a period and calculating the velocity of fluid flow.

17. The apparatus as in claim 15 wherein said fluid is liquid.

18. The apparatus as in claim 15 wherein said fluid is a gas.

19. The apparatus as in claim 15 wherein said output signals are alternating current signals.

20. The apparatus as in claim 17 wherein said liquid is water.

21. The apparatus as in claim 18 wherein said gas is air.

22. A method of producing electrical power form fluid flow, the method comprising the steps:

channeling the fluid flow along a predetermined path which changes from an entry region to a laminar flow region which is more constricted than the entry region;

forming vortices in said laminar fluid flow; and

positioning a plurality of transducers in sequence, each positioned a predetermined distance from the other, in the path of said vortices of producing electrical power in response to pressure applied by said vortices on said transducers, where the step of forming vortices includes the step of positioning a baffle in the path of said laminar fluid flow.

23. The method of claim 22 wherein the step of forming vortices further includes the step of varying the fluid flow so that the Reynold'"'"'s Number representative of the fluid flow is in the range from 40 to 300, conducive for formation of vortices in said flow.

24. The method of claim 23 where a conduit with a predetermined slope is used in channeling the fluid flow, said conduit having an entry portion and a second portion, said entry portion having a cone shape with a predetermined slope relative to said second portion, and the step of varying said flow includes the step of varying said slope.