Optimal Cathodic Protection Of Ship

Abstract

A boundary element method for performing optimal cathodic protection of a ship is proposed in this paper. The method consists of three parts; (1) a method for estimating the potential distribution on the hull from the potential data at fixed several sensors, (2) a method for determining the optimal currents to be impressed from each electrode, and (3) a method for detecting the location of a paint defect from the potential change at the sensors. An example problem is solved by a three dimensional boundary element method to demonstrate the usefulness of the proposed method. INTRODUCTION To prevent corrosion of a ship, the hull is painted and cathodic protection is performed by impressing currents from several electrodes. Some sensors for monitoring potentials are located at several points on the hull. During navigation, it is necessary to estimate the potential on the whole surface of hull from the potential data measured by small number of sensors and determine the optimal currents to be impressed to each electrode. The paint is sometimes damaged during navigation, and it becomes necessary to consider how to detect the paint defect and how to protect the damaged part from corrosion. These are the inverse and optimum problems, and the boundary element method has been successfully applied to this kind of problems[1] [2]. In this Transactions on Modelling and Simulation vol 13, © 1996 WIT Press, www.witpress.com, ISSN 1743-355X