# Electro Static volume (3D) / face (2D) region

## Introduction

The volume (in 3D) / face (in 2D) regions are the material regions used to model the massive regions in the study domain.

## Material regions (massive regions)

Material massive regions enable the modeling of the material media (with materials). The physical properties of the medium are those of the corresponding material region.

A massive region… | enables the modeling… | It is defined by… |
---|---|---|

air or vacuum |
air or a vacuum (permittivity |
(predefined) |

perfect conductor |
of a perfect conductor medium: equipotential frontier (floating or fixed value of electric potential) with a normal electric field |
an electric potential: floating or fixed value (in |

Dielectric (+ electric charge sources q) |
of a dielectric medium (relative permittivity |
a material with : permittivity C) or volume density (in C/m)
(formula with input/output parameters or formula with spatial
quantities)^{3} |

## Expression of the electric charge density

In the case, where electric charge source exists in the region, this one can be expressed in various ways.

The electric charge source can be expressed by:

- a total value (in C)
- a volume density (in Cm 3 ):

- uniform: constant value or formula with input/output parameters
- space dependent: formula with spatial quantities