Omni-directional radiator for multi-transducer array

• US 8,218,398 B2
• Filed: 11/04/2009
• Issued: 07/10/2012
• Est. Priority Date: 11/12/2008
• Status: Active Grant

• Current Assignee: Curtis E. Graber
• Original Assignee: Curtis E. Graber
• Inventors: Graber, Curtis E.
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): HULKA, JAMES R
• Application Number:
  US12/590,182
• Publication Number:
  US 20100119090A1
• Time in Patent Office: 979 Days
• Field of Search: 367/133, 367/153, 381/182
• US Class Current: 367/133
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 1/44 Special adaptations for subaqueous use, e.g. for hydrophone
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• CPC Class Codes: H04R 2201/401 2D or 3D arrays of transducers

Abstract

An omni-directional acoustic horn for applications in a liquid transmission medium deploys a plurality of transducers distributed along an interior face of the horn to radiate against an opposed surface. The arrangement mimics operation at a greater depth of submergence to depress development of acoustic cavitation bubbles.

Claims

1. An acoustic radiator for suppression of cavitation in a liquid transmission medium, the acoustic radiator comprising:

an interior face;

an interior boundary located opposed to and spaced from the interior face;

a central core connecting the interior face to the interior boundary; and

a plurality of submersible transducers distributed on the interior face and oriented to radiate sound away from the interior face against the interior boundary where the sound is contained and directed across the interior boundary and the interior face, the plurality of submersible transducers being organized into at least first and second sub-arrays, the second sub-array being located in succession to the first sub-array as determined by a primary local direction of propagation of the reflected sound.

2. The acoustic radiator of claim 1, further comprising a half shell and a disk baffle to support the interior boundary and the interior face, respectively, the half shell and the disk baffle defining a toroidal waveguide having a central core providing for globally omni-directional radiation of sound from the central core to a mouth and outwardly from the mouth.

3. The acoustic radiator of claim 2, wherein the interior face is one of first and second major surfaces of a disk baffle, with first and second interior boundaries opposing the first major surface and a second major surface of the disk baffle, respectively, and pluralities of submersible transducers being distributed on the first and the second major surfaces of the interior baffle in two toroidal waveguides.

4. The acoustic radiator of claim 2, including a plurality of toroidal waveguides stacked into a waveguide.

5. The acoustic radiator of claim 3, further comprising:

the submersible transducers being piezoelectric devices.

6. The acoustic radiator of claim 5, further comprising:

the successive sub-arrays of submersible transducers including greater numbers of transducers with increasing proximity to the mouth.

7. The acoustic radiator of claim 6, further comprising:

at least a first radial baffle extending to the mouth of the toroidal waveguides.

8. The acoustic radiator of claim 6, further comprising:

a plurality of radial baffles extending from the central core to the mouth dividing each toroidal waveguide into a plurality of signal channels within each toroidal waveguide.

9. An acoustic radiator comprising:

an arcuate mouth;

a waveguide extending from the mouth to a base, the waveguide being defined by first surface and a second opposed surface;

a plurality of water submersible acoustic transducers distributed along one of the first and the second opposed surface; and

drive circuitry for the water submersible acoustic transducers for synchronously reinforcing a sound wave propagating along the length of the waveguide from the base to the arcuate mouth by operating those of the plurality of water submersible acoustic transducers on the first surface.

10. The acoustic radiator of claim 9, wherein the plurality of water submersible acoustic transducers reinforce the sound wave keeping a stable frequency spectrum.

11. The acoustic radiator of claim 10, further comprising:

the plurality of water submersible acoustic transducers being organized into sub-arrays defined by distance of the acoustic transducers in a sub-array from the arcuate mouth; and

a ratio of the surface area of the water submersible acoustic transducers in any sub-array relative to the length of the arc of the sub-channel for the sub-array being a constant.

12. The acoustic radiator of claim 11, further comprising;

a second waveguide with water submersible acoustic transducers mounted in a baffle providing major surfaces for the first surface for both the first and second sound channels.

13. The acoustic radiator of claim 12, further comprising:

ring dampening elements positioned between the first and second surfaces of the sound channels.

14. An acoustic radiator comprising:

an arcuate waveguide, which may be extended through a full circle to form a toroidal waveguide;

the arcuate waveguide including first and second facing interior surfaces forming wave propagation boundaries;

a plurality of liquid submersible acoustic transducers arranged in a constellation along one of the first and second facing interior surfaces;

the plurality of liquid submersible acoustic transducers being oriented to direct sound at the remaining facing interior surface; and

the waveguide terminating at a mouth.

15. The acoustic radiator of claim 14, further comprising:

radial baffles dividing the arcuate waveguide into radial channels.

16. The acoustic radiator of claim 15, including a plurality of toroidal waveguides stacked into a waveguide.