Scale effects and verification of modeling of ship cathodic protection systems

The impressed-current cathodic protection system designed for a U.S. Navy aircraft carrier is evaluated using boundary element techniques. Geometric scaling is introduced by the inclusion of relatively smaller features, such as a bilge keel. The ship is modeled using guidelines developed for a smaller craft. Increases in geometric size result in increases in electrical current demand. Effects of time in service and speed are incorporated by paint damage patterns and use of polarization responses obtained under increased velocity used to simulate ship dynamic conditions. Physical scale modeling of experimental results are used as the basis for evaluation of model accuracy. Detailed comparisons of computational and experimental results show good agreement. As in previous work, model simplification and material characterization accuracy are observed to have a major influence on overall analysis accuracy. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.