Low-Frequency EM Field Penetration Through Magnetic and Conducting Cylindrical Shields
Abstract
Computation of low-frequency field penetration through magnetic and/or conducting materials is important for quantifying electromagnetic compatibility issues in devices and facilities, as well as prediction of field signatures external to ships and submarines due to internal electrical machinery. A computational procedure is described for accurately predicting the penetration of low-frequency fields through a cylindrical structure, possibly arranged in layers. The internal source being shielded is a large multi-turn coil having arbitrary location within the cylindrical shell. Field computation is formulated using multi-region cylindrical harmonic expansions with enforcement of continuity on tangential field components at each material interface. Example field intensities and shielding are computed for a steel pipe at frequencies of 1 Hz and I kHz. The relative effectiveness of induced magnetic shielding and eddy-current shielding is considered.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2005
- Accession Number
- ADA447281
Entities
People
- Michael A. Morgan
Organizations
- Naval Postgraduate School