FEM EquationStaticCurrent

FEM EquationStaticCurrent
Menu location
Solve → Electromagnetic Equations → Static current equation
Workbenches
FEM
Default shortcut
None
Introduced in version
1.1
See also
Electrostatic potential boundary condition, Current density boundary condition, Heat equation

Description

This equation performs static current conduction analyses. It solves the electrostatic potential in a conducting medium allowing volume currents and electric power loss (Joule heating) to be derived.

For info about the math of the equation, see the Elmer models manual, section Static Current Conduction.

Usage

1. After adding an Elmer solver as described here, select it in the Tree view.

1. There are several ways to invoke the command:
   • Press the Static current equation button
   • Select the Solve → Electromagnetic Equations → Static current equation option from the menu.
2. Change the equation's solver settings or the general solver settings if necessary.

Solver Settings

For the general solver settings, see the Elmer solver settings.

The static current equation provides these special settings:

• DataCalculate Joule Heating: Calculates the Joule heating.
• DataCalculate Nodal Heating: Calculates the nodal heating that can be used to couple the heat equation optimally when using conforming finite element meshes.
• DataCalculate Volume Current: Calculates the volume current.
• DataConstant Weights: Turns constant weighting on for the results.
• DataCurrent: Current control value.
• DataCurrent Control: Apply current control with the desired current.
• DataHeat Source: Use Joule heating as a heat source in combination with heat equation.
• DataPower: Power control value.
• DataPower Control: Apply power control with the desired heating power.

Analysis Feature Information

The static current equation takes the following analysis features into account if they are set:

• Electrostatic potential boundary condition
• Current density boundary condition

Note

Except for calculations in 2D, for electrostatic potential boundary conditions it is important that they act on a face or body. Boundary conditions in 3D set to lines or vertices are not recognized by the Elmer solver.

Results

The available results depend on the solver settings. If none of the DataCalculate * settings was set to true, only the electric potential is calculated. Otherwise also the corresponding results will be available.

The possible results are:

• Joule heating in ${\displaystyle {\rm {W/m^{3}}}}$
• Nodal Joule heating in ${\displaystyle {\rm {W}}}$
• Volume current in ${\displaystyle {\rm {A/m^{2}}}}$
• Potential in ${\displaystyle {\rm {V}}}$