Numerical analysis on cathodic protection of underground structures

The presented paper describes the principles of cathodic protection (CP) of underground tanks using the sacrificial anode as well as method of calculation of the potential, current density and polarization distribution on all sides metallic tanks buried underground. Differential equations with boundary conditions are developed and next solved by FEM in 2D and 3D cases. The main goal of this publication is the computation of such distribution of the external protecting electrodes where protected structure will not corrode and next the calculations in 2D and 3D were compared. The article shows that it is sufficient to use 2D analysis for which the speed of equations solution is significantly larger than in 3D space.