Numerical Analysis of Propeller-induced Low-frequency Modulations in Underwater Electric Potential Signatures of Naval Vessels in the Context of Corrosion Protection Systems

D. Schaefer[1], J. Doose[2], A. Rennings[1], and D. Erni[1]
[1]General and Theoretical Electrical Engineering (ATE), Faculty of Engineering, University of Duisburg-Essen, Duisburg, Germany
[2]Technical Center for Ships and Naval Weapons (WTD 71), Bundeswehr, Eckernförde, Germany

Since October 2009 the laboratory of ATE has carried out collaborative research with the WTD 71 that aims for prediction, reduction and optimization of so-called underwater electric potential (UEP) signatures. COMSOL is used to simulate potential distributions in the context of impressed current cathodic protection (ICCP) systems. The electrode kinetics is considered by using boundary conditions based on non-linear polarization curves.

We demonstrate how the polarization resistance flattens singular e-field peaks at sharp edges, hence reducing the UEP signature modulation. The ICCP-current-modulation by means of shadowing effects is considered, focusing on the so-called Vernier-/Nonius effect. In addition an interesting estimation is presented, about what ICCP-settings are recommendable in the context of a silent running (stealth operating mode).