Accession Number : ADA313505

Title :   Low Magnetic Signature Propulsion System.

Descriptive Note : Final rept. 27 Nov 95-27 May 96,

Corporate Author : FOSTER-MILLER INC WALTHAM MA

Personal Author(s) : Cope, D.

PDF Url : ADA313505

Report Date : AUG 1996

Pagination or Media Count : 67

Abstract : The electric propulsion system of the SEAL Delivery Vehicle (SDV) has associated magnetic fields whether operating or not. These fields were measured and documented and the feasibility of a magnetic shielding system was proven during this program. The shielding system was demonstrated on a surrogate electric motor in Foster-Miller's laboratory and by computer simulation of the battery pack. The substitute motor and battery pack simulation were used due to limited availability of the SDV for actual shield installation and validation. The major magnetic field sources of the SDV were: the battery pack, the ferromagnetic motor mass and the operating motor itself. Detection ranges were calculated for each major field source of the SDV and varied depending upon motor load. Actual detection ranges may be greater or lesser depending upon the actual operating conditions, detection threshold sensitivity, and the ambient magnetic noise environment. The shielding system consisted of active magnetic field cancellation for the ferromagnetic motor mass and simulated conductor rerouting for the battery pack. The results of the magnetic signature reduction were: motor field reduced by 21 dB and the battery pack field reduced by 15 dB. This level of magnetic field reduction decreased the calculated detection ranges by 55 percent.

Descriptors :   *ELECTRIC PROPULSION, *ELECTROMAGNETIC SHIELDING, *MAGNETIC SIGNATURES, SIMULATION, VALIDATION, THRESHOLD EFFECTS, REDUCTION, AMBIENT NOISE, MOTORS, NOISE(ELECTRICAL AND ELECTROMAGNETIC), FERROMAGNETISM, LEGENDRE FUNCTIONS, MAGNETOMETERS, MAGNETIC ANOMALY DETECTION.

Subject Categories : Electromagnetic Shielding
      Electric and Ion Propulsion

Distribution Statement : APPROVED FOR PUBLIC RELEASE