Theory and numerical calculation of the acoustic field exerted by eddy-current 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 semi-infinite space; (3) the whole system is axially symmetric; and (4) eddy currents and elastic waves show a steady-state sinusoidal variation. Transonic transducer with axial symmetry was calculated numerically, and the results showed a well-defined 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