Electrogalvanic finite element analysis of partially protected marine structures
A general finite element modeling (FEM) procedure for calculating electrogalvanic field responses due to multiple anodic/cathodic interactions has been developed. Within any defined electrolytic continuum the exact geometry and location of anodes, cathodes, and paint surfaces can now be realistically incorporated in the mathematical model formulation. The anodic/cathodic interactions in the conductive electrolyte are predicted by the application of classical d.c. electric field theory for conductive continuums in conjunction with widely accepted laboratory oxidation/reduction responses for the electrodes. The electrogalvanic fields in the electrolyte are calculated using the scalar Poisson equation whereby traditional boundary conditions are prescribed in the far field of the electrolyte. In the near field of the anodes, cathodes, and the painted metallic substrate, complex boundary conditions are enforced based on empirical polarization curves and paint impedance values. The ionic current in the electrolyte leaving the anode and arriving at the cathodes are mathematically constrained to sum to zero over the metallic surface (spatial Kirchoff's law). Three example problems (three dimensional) of an iron bar in salt water will demonstrate the electrochemical field effects due to relative anodic/cathodic spacing, anodic/cathodic geometries, and infinite paint impedance. A fourth boundary value problem (two dimensional) will illustrate the effect of a paint discontinuity (unprotected area) in the center of the otherwise painted (finite impedance) metallic substrate. The proposed electrochemical modeling procedure has the advantage of concurrently treating numerous essential electrochemical parameters for any geometric anodic/cathodic configurations consistent with the physical laws of electrochemistry.
- Research Organization:
- Office of Engineering Mechanics, Naval Underwater Systems Center, New London, Connecticut
- OSTI ID:
- 5481452
- Journal Information:
- Corrosion (Houston); (United States), Vol. 39:5
- Country of Publication:
- United States
- Language:
- English
Similar Records
Oxidation of Zircaloy Fuel Cladding in Water-Cooled Nuclear Reactors
Modeling a filter press electrolyzer by using two coupled codes within nuclear gen.IV hydrogen production
Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
MECHANICAL STRUCTURES
CATHODIC PROTECTION
SEAWATER
ELECTROCHEMISTRY
ANODES
BOUNDARY CONDITIONS
BOUNDARY-VALUE PROBLEMS
CONFIGURATION
DIRECT CURRENT
ELECTRIC FIELDS
ELECTRODES
ELECTROLYSIS
ELECTROLYTES
FINITE ELEMENT METHOD
GEOMETRY
GEOPHYSICAL SURVEYS
IMPEDANCE
IRON
MATHEMATICAL MODELS
METALS
OXIDATION
PAINTS
POISSON EQUATION
POLARIZATION
REDUCTION
SEAS
THREE-DIMENSIONAL CALCULATIONS
CHEMICAL REACTIONS
CHEMISTRY
COATINGS
CORROSION PROTECTION
CURRENTS
DIFFERENTIAL EQUATIONS
ELECTRIC CURRENTS
ELEMENTS
EQUATIONS
HYDROGEN COMPOUNDS
LYSIS
MATHEMATICS
NUMERICAL SOLUTION
OXYGEN COMPOUNDS
PARTIAL DIFFERENTIAL EQUATIONS
SURFACE WATERS
SURVEYS
TRANSITION ELEMENTS
WATER
423000* - Engineering- Marine Engineering- (1980-)
400400 - Electrochemistry