Describing sources

Introduction

We distinguish two types of sources:

  • an imposed electric charge density (q0)
  • an imposed electric potential (V0)

The describing of these two types of sources in Flux software is detailed in the following blocks.

Imposed electric charge density

It is possible to impose a density of electric charge (q0) on a region by:

  • using the material regions of dielectric type (as presented previously): the volume density of electric charge of sources is then one of the data entered during the definition of the dielectric region
  • using the regions known as non-material of the type:

    imposed density of electric charge

Expression of the electric charge density

The electric charge density of sources represents the q term in the solved equation of electrostatic applications (see § Electro Static: solved equations).

The expression of this density depends on the used type of region. Information by the region type is gathered in the table below.

For a region… the density of the charges is a…
material

massive thin (withthickness) filiform (with cross-section)

volume density (or the total electric charge)

uniform or space dependent
non-material face (3D) surface density
line line density

Imposed electric potential

It is possible to impose an electric potential (V0) on a region by:

  • using the material regions of perfect conductor type (as presented previously): the electric potential is then one of the data entered during the definition of the region
  • using the regions known as non-material of the type: imposed electric potential

Expression of the electric potential

The expression of the electric potential depends on the used type of region.

Information by the region type is gathered in the table below.

For a region… the electric potential is…
perfect conductor uniform
imposed potential uniform or space dependent