Method for designing a resonant acoustic projector

• US 7,548,489 B1
• Filed: 07/05/2006
• Issued: 06/16/2009
• Est. Priority Date: 07/05/2006
• Status: Active Grant

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Young, Jane A., Clark, Joseph A.
• Primary Examiner(s): Pihulic; Dan
• Application Number:
  US11/482,296
• Time in Patent Office: 1,077 Days
• Field of Search: 367/141, 367/142, 367/152, 367/171, 367/172, 367/176, 367/154, 367/174, 367/153, 181/113, 181/120
• US Class Current: 367/142
• CPC Class Codes: G01V 1/02 Generating seismic energy G01V1/003 takes precedence

Abstract

Each of a pair of electrically conductive spiral coils is ensconced in a disk-shaped matrix. The two coil-ensconced matrices are joined face-to-face so as to sandwich between them a thin, non-magnetic elastic layer. An electronic device is connected so that each coil and a corresponding capacitor form an LC circuit. Electrification of the two LC circuits results in the departing and returning, in oscillatory fashion, of the two coil-ensconced matrices. This resonant behavior is both electromagnetic and mechanical in nature. The intermittent electromagnetic repelling is related to the LC circuitry and the oppositely polar electrifications of the respective coils. The springy mechanical activity is based on a spring-mass model and involves the elasticity of the intermediate material and the entrainment of ambient fluid. Underwater acoustic projection performance can be predicted by inputting design parameters in an algorithm inter-relating voltage input, electromagnetic behavior, mechanical behavior, and acoustic energy field output.

Claims

1. A method for modeling underwater acoustic projection apparatus, said method comprising:

(a) defining plural component parameters, said component parameters relating to components of underwater acoustic projection apparatus, said components including a capacitance component, two inductance components, and an elastic component, each said inductance component including a matrix and a spiral-coiled electrical conductor embedded in said matrix, said elastic component being interposed between and abutting said matrices, said capacitance component being electrically connected to said spiral-coiled electrical conductors in inductance-capacitance circuitry in which said capacitance component represents the capacitance and in which said spiral-coiled electrical conductors represent the inductance, said component parameters including;

the number of turns in each said spiral-coiled electrical conductor;

the electrical resistance of each said spiral-coiled electrical conductor;

the spring constant of said elastic component;

the separation between said matrices in the absence of operation of said underwater acoustic projection apparatus; and

the radius of each said matrix;

(b) defining plural operation parameters, said operation parameters relating to operation of said underwater acoustic projection apparatus, wherein during operation of said underwater acoustic projection apparatus voltage input into said inductance-capacitance circuitry results in oscillation toward and away from each other of said two inductance components, said oscillation being associated with electromagnetic resonance of said inductance-capacitance circuitry and with mechanical resonance of a spring-mass system in which said elastic component represents the spring and in which said entrained water represents at least substantially all of the mass, said underwater acoustic projection apparatus producing pressure waves in said water in association with said electromagnetic resonance and said mechanical resonance, said pressure waves being associated with sound radiated by said underwater acoustic projection apparatus, said operation parameters including;

the amount of said voltage input;

the water depth of said underwater acoustic projection apparatus; and

the mass of said entrained water;

(c) determining the amount of said sound radiated by said underwater acoustic projection apparatus, said determining including using the defined said component parameters and the defined said operation parameters in a mathematical relationship, said mathematical relationship including said voltage input, said electromagnetic resonance, said mechanical resonance, and said sound radiated by said underwater acoustic projection apparatus.

2. The method for modeling underwater acoustic projection apparatus as recited in claim 1, wherein said determining includes an assumption of equivalence between the electrical impedance of said voltage input and the electrical impedance of said inductance-capacitance circuitry.

3. The method for modeling underwater acoustic projection apparatus as recited in claim 1, said method further comprising calculating the efficiency of said underwater acoustic projection apparatus, said efficiency being a function of the amount of said voltage input and the amount of said sound radiated by said underwater acoustic projection apparatus.

4. The method for modeling underwater acoustic projection apparatus as recited in claim 3, wherein said determining of the amount of said sound includes assumption of equivalence between the electrical impedance of said voltage input and the electrical impedance of said inductance-capacitance circuitry.

5. The method for modeling underwater acoustic projection apparatus as recited in claim 1, said method further comprising:

performing at least one iteration of steps (a), (b) and (c), each said iteration including at least one change, as compared with at least one previous performance of steps (a), (b) and (c), with respect to at least one said component parameter or at least one said operation parameter;

selecting a set of said component parameters and a set of said operation parameters, said selecting including considering, in correspondence with each performance of steps (a), (b) and (c), the amount of said sound radiated by said underwater acoustic projection apparatus.

6. A machine having a memory, said machine containing a data representation of underwater acoustic projection apparatus, said underwater acoustic projection apparatus including a capacitance component, two inductance components, and an elastic component, each said inductance component including a matrix and a spiral-coiled electrical conductor embedded in said matrix, said elastic component being interposed between and abutting said matrices, said capacitance component being electrically connected to said spiral-coiled electrical conductors in inductance-capacitance circuitry in which said capacitance component represents the capacitance and in which said spiral-coiled electrical conductors represent the inductance, wherein during operation of said underwater acoustic projection apparatus voltage input into said inductance-capacitance circuitry results in oscillation toward and away from each other of said two inductance components, said oscillation being associated with electromagnetic resonance of said inductance-capacitance circuitry and with mechanical resonance of a spring-mass system in which said elastic component represents the spring and in which said entrained water represents at least substantially all of the mass, said underwater acoustic projection apparatus producing pressure waves in said water in association with said electromagnetic resonance and said mechanical resonance, said pressure waves being associated with sound radiated by said underwater acoustic projection apparatus, said data representation being generated, for availability for containment by said machine, by the method comprising:

defining plural component parameters, said component parameters including;

the number of turns in each said spiral-coiled electrical conductor;

the electrical resistance of each said spiral-coiled electrical conductor;

the spring constant of said elastic component;

the separation between said matrices in the absence of operation of said underwater acoustic projection apparatus; and

the radius of each said matrix;

defining plural operation parameters, said operation parameters including;

the amount of said voltage input;

the water depth of said underwater acoustic projection apparatus; and

the mass of said entrained water;

determining the amount of said sound radiated by said underwater acoustic projection apparatus, said determining including using the defined said component parameters and the defined said operation parameters in a mathematical relationship, said mathematical relationship including said voltage input, said electromagnetic resonance, said mechanical resonance, and said sound radiated by said underwater acoustic projection apparatus.

7. The machine of claim 6, wherein said determining includes an assumption of equivalence between the electrical impedance of said voltage input and the electrical impedance of said inductance-capacitance circuitry.

8. The machine of claim 6, said method further comprising calculating the efficiency of said underwater acoustic projection apparatus, said efficiency being a function of the amount of said voltage input and the amount of said sound radiated by said underwater acoustic projection apparatus.

9. The machine of claim 8, wherein said determining includes assumption of equivalence between the electrical impedance of said voltage input and the electrical impedance of said inductance-capacitance circuitry.

10. The machine of claim 6, said method further comprising repeating, at least once:

said defining of said component parameters;

said defining of said operation parameters; and

said determining;

wherein each said repetition includes changing at least one of;

at least one defined said component parameter;

at least one defined said operation parameter.

11. A computer program product for residence in memory of a computer, said computer program product being embodied in computer code and being characterized by computer program logic for enabling a computer to perform modeling of underwater acoustic projection apparatus, said computer code being executable by said computer so that, in accordance with said computer program logic, said computer performs steps including:

defining plural component parameters, said component parameters relating to components of underwater acoustic projection apparatus, said components including a capacitance component, two inductance components, and an elastic component, each said inductance component including a matrix and a spiral-coiled electrical conductor embedded in said matrix, said elastic component being interposed between and abutting said matrices, said capacitance component being electrically connected to said spiral-coiled electrical conductors in inductance-capacitance circuitry in which said capacitance component represents the capacitance and in which said spiral-coiled electrical conductors represent the inductance, said component parameters including;

the number of turns in each said spiral-coiled electrical conductor;

the electrical resistance of each said spiral-coiled electrical conductor;

the spring constant of said elastic component;

the separation between said matrices in the absence of operation of said underwater acoustic projection apparatus; and

the radius of each said matrix;

defining plural operation parameters, said operation parameters relating to operation of said underwater acoustic projection apparatus, wherein during operation of said underwater acoustic projection apparatus voltage input into said inductance-capacitance circuitry results in oscillation toward and away from each other of said two inductance components, said oscillation being associated with electromagnetic resonance of said inductance-capacitance circuitry and with mechanical resonance of a spring-mass system in which said elastic component represents the spring and in which said entrained water represents at least substantially all of the mass, said underwater acoustic projection apparatus producing pressure waves in said water in association with said electromagnetic resonance and said mechanical resonance, said pressure waves being associated with sound radiated by said underwater acoustic projection apparatus, said operation parameters including;

the amount of said voltage input;

the water depth of said underwater acoustic projection apparatus; and

the mass of said entrained water;

determining the amount of said sound radiated by said underwater acoustic projection apparatus, said determining including using the defined said component parameters and the defined said operation parameters in a mathematical relationship, said mathematical relationship including said voltage input, said electromagnetic resonance, said mechanical resonance, and said sound radiated by said underwater acoustic projection apparatus.

12. The computer program product according to claim 11, wherein said determining includes an assumption of equivalence between the electrical impedance of said voltage input and the electrical impedance of said inductance-capacitance circuitry.

13. The computer program product according to claim 11, said computer program logic further comprising means for calculating the efficiency of said underwater acoustic projection apparatus, said efficiency being a function of the amount of said voltage input and the amount of said sound radiated by said underwater acoustic projection apparatus.

14. The computer program product according to claim 13, wherein said determining includes assumption of equivalence between the electrical impedance of said voltage input and the electrical impedance of said inductance-capacitance circuitry.

15. The computer program product according to claim 11, said computer program logic further comprising means for performing at least one repetition of the following:

said defining of said component parameters;

said defining of said operation parameters;

said determining;

wherein each said repetition includes changing at least one of the following;

at least one defined said component parameter;

at least one defined said operation parameter.