On the Effect of Some Critical Parameters in Cathodic Protection Systems: A Numerical /Experimental Study

The potential distribution over the surface of underwater structures depends on a series of environmental parameters in addition to the material properties of the surfaces. Among others, the water velocity, resistivity, temperature, salinity, and dissolved oxygen affect the efficiency of cathodic protection systems. The present work discusses the influence of some of these parameters. Stirring, resistivity of the medium, and geometrical distribution of anodes are particularly considered.

Three electrolytes of distinct conductivities were studied, and for each system analyzed two stirring speeds were used. The systems of cathodic protection were analyzed for three different geometrical configurations between impressed current anodes and cathodes. To assess the influence of the aforementioned parameters, the computer program PROCAT has been used to simulate the experiments. This program is a general application boundary element computer system. It is capable of analyzing three-dimensional, two-dimensional, and axisymmetric corrosion cells, including nonlinear and possibly time-dependent polarization curves. In the present computer simulation, the nonlinear polarization curves were obtained experimentally under different environmental conditions. The experiments were implemented in a rectangular reservoir that was represented as a two-dimensional problem.