舰艇水下腐蚀静电场计算及影响因素仿真分析

Calculation of electrostatic field of underwater corrosion of ship and simulation analysis of influencing factors

摘要:

为了进一步分析影响舰船电场的不同因素,提高舰艇水下静电场仿真分析中电偶极子建模方法的准确性,研究产生舰艇水下腐蚀静电场的腐蚀电化学原理和特性,从腐蚀电流密度的角度推导船体-螺旋桨电偶腐蚀电流表达式,并利用镜像法求解出了空气海水二层模型下水平和垂直电偶极子电场解析式。建立基于舰艇腐蚀电流电偶极子的电场解析模型,在此基础上利用数值仿真对一中型舰艇水下50 m测线上的电场进行分析。结果表明:在设定变化范围内,船体腐蚀电位、螺旋桨腐蚀电位、船体浸水面积、螺旋桨浸水面积、海水温度、海水电导率对舰艇水下腐蚀静电场的影响程度分别约为29%、23%、53%、82%、30%和67%。仿真结果和电场解析模型可以为进一步研究舰艇水下腐蚀静电场特征及防护方法提供有力的理论支撑。

Abstract:

In order to further analyze the different factors affecting ship electric field and improve the accuracy of electric dipole modeling method in ship underwater electrostatic field simulation analysis. The corrosion electrochemical principle and characteristics of underwater corrosion electrostatic field are studied. The expression of galvanic corrosion current of ship-propeller is derived from the angle of corrosion current density. The analytical expressions of horizontal and vertical electric dipole electric field are solved by mirror image method under air-seawater two-layer model. The analytical model of the electric field based on the corrosion current dipole of the ship is established. On this basis, the electric field on the underwater 50 m line of a medium-sized ship is analyzed by numerical simulation. The results show that within the set range of variation, the influence degree of the corrosion potential of the hull and propeller, the immersion area of the hull and propeller, the seawater temperature and the seawater conductivity on the underwater corrosion electrostatic field of the ship are about 29%, 23%, 53%, 82%, 30% and 67%, respectively. The simulation results and the analytical model of the electric field can provide strong theoretical support for the further study of the electrostatic field characteristics and protection methods of underwater corrosion of ships.