Theory and numerical calculation of the acoustic field exerted by eddycurrent forces
Abstract
The equations for calculating the acoustic field produced within a nonmagnetic metal by interaction of eddy currents with a static magnetic field were obtained on the assumptions that: (1) an ultrasonic wave is generated by the electromagnetic force through classical and macroscopic phenomena; (2) the electric, magnetic, and elastic properties of the metal are linear, isotropic, and homogeneous throughout the metal, which occupies semiinfinite space; (3) the whole system is axially symmetric; and (4) eddy currents and elastic waves show a steadystate sinusoidal variation. Transonic transducer with axial symmetry was calculated numerically, and the results showed a welldefined ultrasonic wave beam, which was narrower than had been expected from the size of the transducer.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 January 1976
 Bibcode:
 1976STIN...7629493K
 Keywords:

 Acoustic Propagation;
 Eddy Currents;
 Numerical Analysis;
 Dielectrics;
 Elastic Properties;
 Electromagnetic Fields;
 Magnetic Fields;
 Theoretical Physics;
 Ultrasonic Radiation;
 Electronics and Electrical Engineering