Selecting the Physics Models and Materials

Before you set up the physics continua, prepare the required geometry, regions, interfaces, and mesh, as appropriate to your analysis.

For more information on these general operations, see General Simulation Process.

Create physics continua and assign them to the relevant regions.

In each physics continuum, activate physics models as required. To model electric currents in conducting regions, include the following models:


Group Box	Physics Model
Space	To model a 3D conducting region, activate Three Dimensional. To model a 2D conducting region, activate either Two Dimensional or Axisymmetric. When using the Axisymmetric model, make sure that you use an appropriate mesh resolution near the axis. To model a conducting solid shell region, activate Three Dimensional. You typically use this model in electrochemistry applications to model the electrical conductivity in thin shells. The thickness of the conducting shell must be the same at each location on the shell. However, you can modify the shell thickness during the simulation by specifying the thickness using a field function. For more information on shell regions, see Solid Shell Region and Solid Shell Thickness.
Time	Activate either Implicit Unsteady or Steady.
Material	Choose the relevant material model. You can model electric currents in single-component or multi-component gases, solids, and liquids. Conducting shells are supported only for solid materials. For multi-component materials: The Multi-Part Solid model allows you to define different electrical conductivities for different solid parts within the same physics continuum. The Multi-Component Gas and Multi-Component Liquid models allow you to define the effective electrical conductivity of the mixture. To model electric currents in porous materials, which are particularly relevant for Electrochemistry applications, you can model the porous material as either a porous region, or a fluid region containing solid phases. The second approach requires the Porous Media model. For more information, see Modeling Porous Media.
Optional Models	Activate Electromagnetism.
Electromagnetism	To solve for the electric potential in non-porous materials, activate one of the following models: Harmonic Balance FV Electrodynamic Potential—specifically designed for potentials with sinusoidal time dependence. Electrodynamic Potential—suitable for all other cases. To solve for the electric potential in porous materials, activate the following models: In physics continua associated with porous regions, activate the Electrodynamic Potential model. In physics continua associated with fluid regions containing solid phases, which require the Porous Media model, activate the Electrodynamic Potential model. To solve for the electric potential in a solid phase, activate the Electrodynamic Potential under the relevant phase models.

If relevant, you can activate additional models:

To include the eddy currents induced by time-varying magnetic fields in transient applications, activate one of the magnetic vector potential models (see Modeling Magnetic Fields).
To model electrochemical reactions and species, activate the appropriate electrochemistry model (see Electrochemistry).
For example, you can simulate corrosion and determine the effectiveness of various cathodic protection scenarios.
To model the interaction between electrically conducting fluids (such as molten metals and plasma) and a magnetic field, activate one of the MHD models (see Modeling Magnetohydrodynamics (MHD)).
To model thermoelectric devices such as thermocouples, where differences in temperature between contacting conductors generate voltage, activate the Thermoelectricity model (see Thermoelectricity Model Reference).
To account for the heat dissipated by electric currents in resistive materials, activate the Ohmic Heating model (see Modeling Ohmic Heating).

The Thermoelectricity and Ohmic Heating models require you to activate an energy model.

For each continuum, choose appropriate materials from the Simcenter STAR-CCM+ material library.

You can either choose basic materials from the Standard material database, or you can select materials from the Electromagnetic material database. The Electromagnetic material database contains predefined materials from a variety of vendors and, depending on the material, can include data such as B-H curves and temperature-dependent quantities.

For more information, see General Simulation Process.

For each material, specify the Electrical Conductivity.

For instructions, see Defining the Electrical Conductivity.

Additional material properties may be available, depending on the selected physics models. When using the Thermoelectricity model, specify the material Seebeck Coefficient. You can use a field function to define the Seebeck coefficient as a function of temperature. For more information, see Thermoelectricity Model Reference.