有限差分法计算海底管道阴极保护时的电位分布

CALCULATING POTENTIAL DISTRIBUTIONS OF CATHODICALLY PROTECTED SUBSEA PIPELINE WITH FINITE DIFFERENCE METHOD

测量了并用有限差分方法（ＦＤＭ）汁算了在装有海泥的槽中被保护海底管道表面的电位分布以及电位分布随保护时间的变化．计算结果与测量结果吻合得很好，这说明ＦＤＭ能够应用于海底管道阴极保护电位分布计算．

Abstract The potential distributions and their changes with time on the surface of a cathodically protected pipe, which is put into a vessel containing sea mud, were measured experimentally and calculated with finite difference method (FDM).The calculated data are in good agreement with measured ones. Since the boundary conditions in our experimental device are the same as in systems in which the subsea pipe was cathodically protected by sacrificial anodes (SA) in the shape of bracelet, these results show that FDM can be used in the design and monitoring of cathodic protection systems for subsea pipelines.Considering the non-linear boundary conditions on the surface of the pipe and SA, iteration numerical method has been used in our program to obtain the calculated data. An over-relaxation method has also been used to decrease the number of iteration and to speed up the calculation. The relaxation parameter α=1 .81.