Setting up the Physics

Set up physics continua for both the fluid electrolyte and the solid shell plating on the grille.

To define the physics continua:
  1. For the physics continuum, Continua > Electrolyte, select the following models in order:
    Group Box Model
    Enabled Models Three Dimensional (selected automatically)
    Solution Interpolation (selected automatically)
    Time Steady
    Material Liquid
    Flow Segregated Flow
    Gradients (selected automatically)
    Equation of State Constant Density
    Viscous Regime Laminar
    Optional Models Electromagnetism
    Electromagnetism Electrodynamic Potential
    Optional Models Electrochemistry
    Electrochemistry Electrochemical Reactions
  2. Click Close.
Set up the reaction mechanism at the surface:
  1. Expand the Continua > Electrolyte > Models node.
  2. Right-click the Electrochemical Reactions > Surface Mechanism Manager node and select New Surface Mechanism.
  3. Rename the Surface Mechanism Manager > Surface Mechanism node to Chrome.
  4. Right-click the Surface Mechanism Manager > Chrome > Reacting Surface > Reactions node and select New Reaction.
  5. Rename the Reactions > Reaction 1 node to Cr = Cr3+ + 3e-
  6. Select the Reactions > Cr = Cr3+ + 3e- > Properties > Reaction Formulation node and set Select Method to Tabular.
  7. Select the Reaction Formulation > Tabular Polarization Curve node and set the following properties:
    Property Setting
    Table Song_Cr3+Polarization
    Electric Potential potential
    Specific Electric Current current density
Since the electrolyte is an aqueous solution, most of the material properties for water are suitable for the simulation. However, to account for the conducting ions in solution, the Electrical Conductivity must be adjusted.
  1. Within Electrolyte > Models, select the Liquid > H2O > Material Properties > Electrical Conductivity > Constant node and set Value to 34.1 S/m.
  2. Select the Continua > Electrolyte > Initial Conditions > Electric Potential node and set Value to 1.0 V.
Create a physics continuum for the pre-coated layers of copper and nickel onto which the chromium is electroplated. In this tutorial, default initial conditions are maintained for this physics continuum.
  1. Create a physics continuum. Rename the resulting Physics 1 node to Plating.
  2. For the physics continuum, Continua > Plating, select the following models in order:
    Group Box Model
    Space Three Dimensional
    Time Steady
    Optional Models Solid
    Electromagnetism
    Enabled Models Gradients (selected automatically)
    Shell Electrodynamic Potential (selected automatically)
    Optional Models Electrochemistry
    Enabled Models Electrochemical Reactions (selected automatically)
  3. Click Close.
The electrochemical reactions occur in the electrolyte at the boundaries to the anode and cathode. Therefore, conditions and values are specified at the anode and cathode boundaries. The thin layer of pre-plated copper and nickel is defined as a separate shell region which occurs at the boundary between the electrolyte and the grille (cathode) part. The chrome ions from the electrolyte are then deposited as chrome atoms on top of the shell region.
  1. Expand the Regions > Electrolyte > Boundaries > Anode node and set the following Properties:
    Node Property Setting
    Physics Conditions
    Electric Potential Specification Method Specific Electric Current
    Physics Values
    Specific Electric Current Value 165.25 A/m^2
  2. Right-click the Regions > Electrolyte > Boundaries > Grille node and select Create Shell Region.
  3. Rename the Regions > Grille shell node to Grille and set its Continuum property to Plating.
    The Type is set to Solid Region automatically since a solid continuum is specified.
  4. Select the Regions > Grille > Physics Values > Shell Thickness node and set Value to 1.0E-6 m:
    This shell thickness represents the thickness of the copper and nickel layer on the plastic part.
  5. Expand the Grille > Boundaries > Rack edges node and set the following properties:
    Node Property Setting
    Physics Conditions
    Electric Potential Specification Method Electric Potential
    Physics Values
    Electric Potential Value 0.0 V
  6. Select the Interfaces > In-place 1 > Physics Conditions > Electrochemistry Mechanism Option node and set Mechanism to Chrome.
  7. Click (Save).