Corrosion Module Updates
For users of the Corrosion Module, COMSOL Multiphysics® version 5.3a brings a new feature for defining reactions on a thin electrode and two new corrosion tutorials. Read more about the corrosion news below.
New Thin Electrode Surface Node
The Thin Electrode Surface feature can be used to define electrode reactions occurring on a thin electrode that is fully immersed in electrolyte. The geometry representation of the electrode is assumed to be infinitely thin and is only applicable to internal boundaries of electrolyte domains. This can be used as an alternative to drawing the actual electrode domain in the model geometry, which can significantly reduce meshing and solver time, especially in 3D models. You can typically use this feature to model electrodeposition or corrosion processes occurring on thin sheets of metal.
The propeller blade in the Ship Hull tutorial in the Corrosion Module Application Library is now defined using the new Thin Electrode Surface feature.
Revamped Free and Porous Media Flow Interface
With the new version of the Free and Porous Media Flow interface, you can couple laminar or turbulent free flow with porous media flow. This interface remains unique in its coupling with the electrochemistry interfaces for the modeling of porous electrodes.
Kozeny-Carman Permeability Model
The Kozeny-Carman permeability model, available for the Darcy's Law interface in COMSOL Multiphysics® version 5.3a, allows you to estimate the permeability of granular media from the porosity and particle diameter.
New Tutorial Model: Stress Corrosion
The new Stress Corrosion tutorial simulates the effect of elastic and plastic deformations on corrosion and, in particular, how the corrosion rate is accelerated by longitudinal strains in the plastic deformation region. The model is implemented by coupling the Solid Mechanics interface to the Secondary Current Distribution interface. The computed local stresses and strains from the Solid Mechanics interface are used in the electrode surface kinetics expressions to calculate the electrolyte potential and current density in the soil.
Stresses in a solid alloy steel pipe and the resulting potential distribution and current streamlines in the adjacent soil, acting as an electrolyte. The higher strains in the thinner part of the pipe results in a higher corrosion rate.
Application Library path:
Corrosion_Module/Galvanic_Corrosion/stress_corrosion
New Tutorial Model: Stray Current Pipeline Corrosion
The new Stray Current Pipeline Corrosion model demonstrates stray current corrosion of a buried pipeline. The buried pipeline is located close to a crossing pipeline that is protected by an impressed current cathodic protection (ICCP) system. The model calculates and predicts the corrosion rate of the nonprotected pipeline, which is much higher close to the crossing.
Stray current corrosion rate along a pipe shown with an Arrow Line plot.
Application Library path:
Corrosion_Module/Galvanic_Corrosion/stray_current