Accession Number : ADA255227


Title :   Surface Impedance Modification of Plates in a Water-Filled Waveguide


Corporate Author : NAVAL RESEARCH LAB ORLANDO FL UNDERWATER SOUND REFERENCE DIV


Personal Author(s) : Dubbelday, Pieter S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a255227.pdf


Report Date : Jan 1992


Pagination or Media Count : 6


Abstract : The interaction of parallel waves, propagating in a water-filled cylindrical wave-guide, with a plate perpendicular to its axis is determined by the plate's specific acoustic impedance, the product of density and wave speed. By means of an attached piezoelectric disk-shaped double transducer, (sensor and actuator), the apparent surface impedance of the plate is modified to equal the impedance of the medium, thus establishing a no-reflection situation. The actuator voltage is regulated by a feedback loop, based on an algorithm for complex-root finding.


Descriptors :   *ACOUSTIC IMPEDANCE , VELOCITY , ALGORITHMS , DENSITY , INTERACTIONS , MODIFICATION , WATER , MATERIALS , STRUCTURES , VOLTAGE , SURFACES , AVAILABILITY , PLATES , FEEDBACK , TRANSDUCERS , ACTUATORS , DISKS , LOOPS , ACOUSTIC REFLECTION


Subject Categories : Acoustics


Distribution Statement : APPROVED FOR PUBLIC RELEASE