USA As Represented by Secretary of the Navy

Joseph A Clark

Jane Ann Young

Michael A Sartori

Paul M Moore

Joel B Gaspin

Daniel F Dozier

Moon H Cho

The present invention, as typically embodied, represents a novel methodology for effecting linear processing of output signals that are received from one or more acoustic vector sensors. First, as pertains to each modal beam, the modal beam amplitude response b, is calculated as the matrix product of a data vector d and a modal weighting vector w, wherein the weighting vector wis uniquely defined in terms of three different linear modal weighting vector equations corresponding to w, w, and w, respectively. Second, as pertains to all of the modal beams, the directional beam amplitude response bis calculated as the sum of all of the individual modal beam amplitude responses b. Because the inventive processing methodology is linear in nature (as distinguished from non-linear, e.g., quadratic, in nature), inventive practice is highly effective for performing quantitative acoustic measurements of sound fields.

Modal beam processing of acoustic vector sensor data

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.

Method for designing a resonant acoustic projector

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. The dual oscillatory modes are merged at the same frequency through tuning of either/both oscillatory mode(s). In many applications, an inventive acoustic projector produces pressure waves underwater.

Resonant acoustic projector

Biological agents in solution within an underwater treatment zone are transferred by infusion to living cells under an acoustic energy field of limited duration and certain accompanying water flow and temperature conditions to maximize processing efficiency.

Acoustic fusion of aquatic animal tissue cells with biological agents

A reusable low frequency projector system that is capable of producing coherent broadband, high power, low frequency acoustic pressure waves underwater. The projector has two halves each with a spiral wound insulated wire core. The spiral wound wires are separately encapsulated and then joined flexibly in a contiguous parallel orientation. When energized by a voltage source the encapsulated spiral wound wires are repelled from one another and then come back together when not energized, imparting a pressure wave to the water at a desired frequency. The projector requires no pressure compensation devices for operation.

Low frequency acoustic projector

An array of piezoelectric transducers from which acoustical energy is emid at a low and high frequency within a predetermined frequency band, synthesizes a localized underwater simulation of a remotely located explosion pressure field, by programmed computer control over the electrical energy input from a signal frequency generator transmitted through power transfer circuitry to the array of acoustic projecting transducers.

System for simulation of underwater explosion pressure fields

A pressure generating system uses a shock wave chamber filled with a liquid pressurized to a static pressure different from ambient atmospheric pressure. Once a a preferred location is established in the chamber, a pulsed compressional acoustic shock wave introduced into the liquid is reflected from a free surface of the liquid as a dilatation wave focused on a point at which a bubble forms and expands about an object. The static pressure causes the bubble to collapse around the object to generate a high pressure thereat.

System for focused generation of pressure by bubble formation and

Acoustic near field measurement apparatus uniquely featuring mechanical eomy, in terms of placement and motion of one or more acoustic measurement devices, which is accorded by the geometric character of a structure having indicia of symmetry. One or more devices are arranged, and/or caused to move with up to three degrees of freedom, so as to manifest conformance with respect to the surface of the structure. If desired, virtually complete acoustic near field mapping of the structure can be effectuated. Examples of the various embodiments of this invention include: circumferentially conformal arrayal of devices in combination with longitudinal movement of the arrayal; longitudinally conformal arrayal of devices in combination with circumferential movement of the arrayal; movement of one or more devices in a path or paths which are circumferentially conformal; movement of one or more devices in a path or paths which are longitudinally conformal; movement of one or more devices in a path or paths which are radial. For some embodiments a single device can be caused to move circumferentially, longitudinally and radially, and thus is provided three degrees of freedom. The apparatus according to this invention is more feasible and reliable than previous apparatus, especially for larger structures.

Apparatus for acoustic near field scanning using conformal arrayal

Acoustic near field measurement method uniquely featuring mechanical econ, in terms of placement and motion of one or more acoustic measurement devices, which is accorded by the geometric character of a structure having indicia of symmetry. One or more devices are arranged, and/or caused to move with up to three degrees of freedom, so as to manifest conformance with respect to the surface of the structure. If desired, virtually complete acoustic near field mapping of the structure can be effectuated. Examples of the various embodiments of this invention include: circumferentially conformal arrayal of devices in combination with longitudinal movement of the arrayal; longitudinally conformal arrayal of devices in combination with circumferential movement of the arrayal; movement of one or more devices in a path or paths which are circumferentially conformal; movement of one or more devices in a path or paths which are longitudinally conformal; movement of one or more devices in a path or paths which are radial. For some embodiments a single device can be caused to move circumferentially, longitudinally and radially, and thus is provided three degrees of freedom. The method according to this invention is more feasible and reliable than previous methods, especially for larger structures.

Method for acoustic near field scanning using conformal arrayal

A system and method are provided to reduce a structure's far field acoustic adiation signature. A plurality of acoustic sensors are positioned in the acoustic near field of the structure for measuring the near field acoustic radiation of the structure. A programmable controller generates a prediction of the structure's far field acoustic radiation signature using the near field acoustic radiation. The prediction is then used to generate a noise control signal applied to a plurality of acoustic radiators suspended within the structure. The radiators convert substantially all of the noise control signal to airborne acoustic energy within the structure.

Far field acoustic radiation reduction

A method and system for mapping the acoustic near field of a stationary al symmetric structure are provided. The structure is subjected to a rotating excitation energy profile from a plurality of stationary excitation sites located radially around the structure. The acoustic near field of the structure due to the rotating excitation energy profile is measured along at least one line that conforms to a longitudinal surface of the structure. Mapping of the acoustic near field is complete when one rotation of the rotating excitation energy profile is complete.

Method and system of mapping acoustic near field

An acousto-optical modulator for modulating light with surface waves. Sure waves are excited on an aluminum plate which is tapered to terminate in a wedge type formation, the surface wave transmitted in the direction of the wedge. The waves are amplified by the wedge and transmitted to a membrane, which has been mirrored on one surface and stretched over a U shaped frame and part of the wedge. Light illuminating the mirrored surface is both spatially and temporally modulated by the surface waves transmitted through the wedge to the membrane.

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Arlington, VA, United States of America

Joseph A Clark