FEM ConstraintElectrostaticPotential

Description

Creates a FEM boundary condition for the electrostatic potential. To be used together with the Electrostatic, Electricforce, Magnetodynamic, Magnetodynamic2D or Static current equation.

introduced in 1.1: Works also with the refactored CalculiX solver object.

introduced in 1.2: Can also be used to apply a magnetic flux density boundary condition.

Electrostatic potential boundary condition in the capacitance of two spheres FEM Example

Usage

1. There are several ways to invoke the command:
   • Press the Electrostatic Potential Boundary Condition button.
   • Select the Model → Electromagnetic Boundary Conditions → Electrostatic Potential Boundary Condition option from the menu.
2. 1.1 and above: Select a boundary condition type and its parameters:
   • Dirichlet - select and specify Potential or Electromagnetic Potential. Optionally, set Electric Infinity (1.2 and above: Far field) and Potential Constant.
   • Neumann - specify Electric Flux Density or (introduced in 1.2) check Magnetic flux density and specify its vector components.
3. Optionally, define the Capacitance Body.
4. Press the Add button.
5. In the 3D View select the object the boundary condition should be applied to. introduced in 1.1: To remove objects from the selection, press the Remove button.

Options

The dialog offers the following settings:

• Boundary Condition: To choose between Dirichlet (prescribed potential) and Neumann (prescribed electric flux density) boundary condition type. introduced in 1.1
• Potential: The electric potential in V.
• Electromagnetic Potential: To enable the input of the components of a potential vector field.
  • x/y/z: The real/imaginary part of the potential in x, y or z-direction in V. For other coordinate systems than Cartesian 3D, this will be the first, second or third coordinate of the system instead of x, y or z. If the coordinate system has no third coordinate, z will be ignored.
  • x, y, z checkboxes: To declare the corresponding potential as unknown for the solver.
• Electric Infinity (1.2 and above: Far field): Option to make a spherical approximation that the volume above the face extends to infinity.
• Potential Constant: Option to set a constant potential.
• Electric Flux Density: The electric flux density (electric displacement field D) in C/m^2. introduced in 1.1
• Magnetic Flux Density To enable the input of the components of a magnetic flux density in mT. introduced in 1.2
  • x/y/z: The real/imaginary part of the magnetic flux density in x, y or z-direction in mT. For other coordinate systems than Cartesian 3D, this will be the first, second or third coordinate of the system instead of x, y or z. If the coordinate system has no third coordinate, z will be ignored.
  • x, y, z checkboxes: To declare the corresponding magnetic flux density as unknown for the solver.
• Capacitance Body: Counter of the body (or face) with a capacitance.

Notes

• The following are Elmer-specific features and won't work with CalculiX:
  • Capacitance Body
  • Electric Infinity (1.2 and above: Far field)
  • Potential Constant
  • introduced in 1.2: Magnetic Flux Density