Granted Patent B2

US 8,069,910 · App. 11/248,542 · Granted Dec 6, 2011

Abstract

Claims (66)

1. A thermal management system, comprising:

a synthetic jet ejector driven by an acoustical resonator having a first pipe; wherein said acoustical resonator operates at one of its resonance frequencies, wherein said acoustical resonator has a plurality of harmonic resonance frequencies f 2 , f 3 , . . . , f n in addition to a primary resonance frequency f 1 , wherein the primary resonance frequency f 1 and the harmonic resonance frequencies f 2 , f 3 , . . . , f n are determined by the length L 1 of the first pipe, and wherein the relationship between the k th resonance frequency f k and the length L 1 is given by

f

k

=

(

2

⁢

k

-

1

)

⁢

c

4

⁢

L

1

where c is the speed of sound in the ambient fluid.

2. The thermal management system of claim 1 , wherein said acoustical resonator is a Helmholtz resonator.

3. The thermal management system of claim 1 , wherein said acoustical resonator comprises a cavity and an orifice, and wherein said cavity has a diaphragm mounted on a surface thereof.

4. The thermal management system of claim 1 , wherein said acoustical resonator comprises a cavity which is partitioned into first and second compartments, and wherein each of said first and second compartments has an orifice therein.

5. The thermal management system of claim 1 , wherein said acoustical resonator comprises a cavity which is partitioned into first and second compartments, and wherein each of said first and second compartments is in open communication with a pipe.

6. The thermal management system of claim 5 , wherein the volume of the first compartment is essentially equal to the volume of the second compartment.

7. The thermal management system of claim 6 , further comprising a diaphragm which is open to both of said first and second compartments.

8. In combination with a synthetic jet ejector, a Helmholtz resonator which drives said synthetic jet ejector at a resonance frequency of said Helmholtz resonator, said combination comprising:

a cavity;

a partition which divides said cavity into first and second compartments;

a diaphragm which extends into said first and second compartments;

a transducer adapted to vibrate the diaphragm; and

first and second pipes which are in open communication with said first and second compartments, respectively;

wherein the resonator has a plurality of harmonic resonance frequencies f 2 , f 3 , . . . , f n in addition to a primary resonance frequency f 1 , wherein the primary resonance frequency f 1 and the harmonic resonance frequencies f 2 , f 3 , . . . , f n are determined by the length L 1 of the first pipe, and wherein the relationship between the k th resonance frequency f k and the length L 1 is given by

f

k

=

(

2

⁢

k

-

1

)

⁢

c

4

⁢

L

1

where c is the speed of sound in the ambient fluid.

9. The combination of 8 , wherein the volume of said first compartment is essentially equal to the volume of said second compartment.

10. The combination of claim 8 , wherein at least one of said first and second pipes extends through a heat exchanger.

11. The combination of claim 8 , wherein said transducer comprises an electromagnetic coil.

12. The combination of claim 8 , wherein the ratio L 2 /L 1 of the length L 1 of the first pipe to the length L 2 of the second pipe is approximately 3:1.

13. The combination of claim 12 , wherein the Helmholtz resonator provides an essentially uniform output over a frequency span of at least 3 octaves.

14. The combination of 8 , wherein the volume of said first compartment is different from the volume of said second compartment.

15. The combination of claim 8 , wherein the primary resonances of the first and second compartments occur at essentially the same wavelength λ, and wherein the first and second pipes have diameters of about ⅕λ or less.

16. The combination of claim 15 , wherein the distance between the first and second pipes is on the order of about ⅕λ or less.

17. The thermal management system of claim 1 , further comprising a heat sink which is equipped with a plurality of heat fins, wherein said acoustical resonator comprises an internal cavity which is in open communication with the external environment by way of a neck, and wherein said neck has said plurality of heat fins disposed therein.

18. The thermal management system of claim 17 , wherein said neck has a maximum diameter d n taken along a plane perpendicular to its longitudinal axis, wherein said cavity has a maximum diameter d c taken along a plane perpendicular to its longitudinal axis, and wherein d c >d n .

19. The thermal management system of claim 5 , wherein said first compartment is in open communication with a first pipe which extends in a first direction away from said first compartment, wherein said second compartment is in open communication with a second pipe which extends in a second direction away from said first compartment, and wherein said first and second directions are opposing directions.

20. The thermal management system of claim 19 , wherein said first pipe has a first longitudinal axis, wherein said second pipe has a second longitudinal axis, and wherein said first and second longitudinal axes are parallel.

21. The thermal management system of claim 20 , wherein said first and second longitudinal axes coincide.

22. The thermal management system of claim 19 , further comprising a diaphragm which is open to both of said first and second compartments.

23. The thermal management system of claim 19 , further comprising a diaphragm which forms a portion of the wall of said first and second compartments.

24. The thermal management system of claim 1 , wherein said acoustical resonator comprises a cavity which is partitioned into first and second compartments, and wherein said first compartments is in open communication with said first pipe.

25. The thermal management system of claim 24 , further comprising a second pipe, wherein said second compartments is in open communication with said second pipe.

Assignments (10)