Accession Number : ADD010058

Title :   Ferrofluid Transducer.

Descriptive Note : Patent,


Personal Author(s) : Dubbelday,Pieter S ; Timme,Robert W

Report Date : 30 Nov 1982

Pagination or Media Count : 4

Abstract : An underwater sound generator composed of a ferrofluid contained within a toroidal container which has a rigid bottom and top and elastic cylindrical side walls. A coil of wire links the toroidal container and is adapted to be connected to a dc bias source to produce a biasing magnetic field, HBIAS, which drives the magnetization of the ferrofluid well into saturation. Two oppositely wound coils of wire respectively link the inner side wall and the outer side wall and are adapted to be connected in series to an ac signal source to produce a time-varying magnetic field, HAC, which modulates HBIAS. The wires are equally spaced in the volume occupied by the ferrofluid. The gradient of HAC in the radial direction provides the time-varying force on the ferrofluid. The resulting ferrofluid motion in the radial direction is transmitted through the outer elastic side wall to supply acoustic motion to the surrounding water. (Author)

Descriptors :   *Patents, *Underwater sound generators, *Ferroelectric materials, *Fluids, Transducers, Low frequency, Magnetic fields, Displacement reactions, Motion, Cylindrical bodies, Elastic shells, Inventions

Subject Categories : Acoustic Detection and Detectors
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE