Open AccessSimulations and Measurements of Eddy Current Magnetic Signatures
Author(s) -
Paweł Polański,
Franciszek Szarkowski
Publication year - 2018
Publication title -
zeszyty naukowe akademii marynarki wojennej/zeszyty naukowe - akademia marynarki wojennej im. bohaterów westerplatte
Language(s) - English
Resource type - Journals
eISSN - 2300-5300
pISSN - 0860-889X
DOI - 10.2478/sjpna-2018-0028
Subject(s) - eddy current , magnetic field , demagnetizing field , magnetization , hull , current (fluid) , mechanics , field (mathematics) , physics , geophysics , engineering , marine engineering , mathematics , quantum mechanics , pure mathematics , thermodynamics
Eddy current magnetic signature is, together with magnetization of ferromagnetic hull, mechanisms and devices on board, corrosion related and stray field sources one of the main sources of ship’s magnetic signature. Due to roll, pitch and yaw of the ship in external magnetic field, eddy currents are induced in conducting materials on board ship, mainly in conducting hull. Flow of those currents is a source of magnetic field around a ship. Principal eddy current component is related to roll movement as it depends on rate of change of external field which is the highest for roll. Induced currents have both in-phase and quadrature components. Magnitude of the eddy current magnetic field can have significant effect on total magnetic field signature after degaussing for ships such as mine sweepers and mine hunters. Paper presents calculations and simulations as well as measurements of model and physical scale model made of low magnetic steel performed in Maritime Technology Center. Contribution of eddy current magnetic field in total field in low roll frequencies has been estimated.