An Investigation of Magneto-Acoustic Effects in Conductive Fluids.
Abstract
An acoustic wave propagating in a conductive medium in the presence of a magnetic field will induce electric potential fields and currents, and, associated with the electric currents, secondary magnetic fields. This interaction is of interest because it occurs in acoustic propagation through sea water in the presence of the earth's magnetic field, and at ultra-low frequency (ULF), acoustic waves should be detectable. A Green's function solution in an infinite medium is developed, with an infinite magnetic field and an infinite plane acoustic wave, from which it can be seen that the magneto-acoustic coupling strength varies linearly with the strength of the acoustic wave and with the magnetic field, and is inversely proportional to frequency. An experiment is described and analyzed in which this interaction is verified for a specific laboratory geometry to within an order of magnitude. Possible sources of the discrepancy in the magnitude of the effect are discussed, and some potential refinements for future experimentation are also noted. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1979
- Accession Number
- ADA084025
Entities
People
- Robert Franz Klaus
Organizations
- Naval Postgraduate School