# Thermal application: definition

## Available applications: reminder

Thermal applications available in Flux are as follows:

- Steady State Thermal application (2D/3D),
- Transient Thermal application (2D/3D)

Specific features of these applications are presented in chapter Thermal applications: principles.

## Definition

To define total conditions of modeling, the user must describe a certain number of specific characteristics, listed in the following blocks.

## Unit of temperature (2D/3D)

During the process describing the physical properties, values of temperature are entered by the user (imposed temperature, external temperature...). These data are defined in the unit of temperature of the application.

The options provided for the unit of temperature are as follows:

- kelvin
- degree Celsius

## Domain type (2D specific feature)

It is possible to carry out a 2D plane study or an axisymmetric study for the same geometric description (in the XY-plane). These two possibilities are presented in the table below.

Type of study domain | |
---|---|

2D Plane |
The device, described in a XY-plane cross-section, is infinitely extended in a direction (The depth of the device is then necessary for the computation of global quantities such as power) |

Axisymmetric |
The device, described in a XY-plane cross-section, has a symmetry around the Y-axis |

## Solver type (2D specific feature)

It is a priori possible to use one of the Flux 2D solvers or one of the Flux 3D solvers for the same geometric and physical description. These two options are presented in the table below.

Solver | |
---|---|

Flux 2D solver |
A solving process is carried out with a Flux 2D solver (it is the default option) |

Flux 3D solver | Not available for the thermal applications in the current version (9.30) |