Thermal¶

Type:	enum
Range:	Cylindrical, Fixed, Flux, Radiating
Default:	-/-
Appearance:	optional

This parameter fixes the type of boundary conditions for thermal simulation projects.

The following boundary types are allowed:

Fixed: Fixes the temperature at the boundary by specifying by specifying a temperature field.
Radiating: Implements a Stefan-Boltzmann radiation condition,

$\begin{eqnarray*} k \partial_n T & = & \varepsilon \sigma \left( \SField{T}^4-\SField{T}_{\mathrm{env}}^4 \right), \end{eqnarray*}$

where $k$ is the thermal conductivity (c.f. ThermalConductivity), $\varepsilon$ is the emissivity of the surface (c.f. Emissivity), $\sigma$ is the Stefan-Boltzmann constant, and $\SField{T}_{\mathrm{env}}$ is the temperature of the surrounding heat reservoir.

The Stefan-Boltzmann law depends non-linearly from the temperature $T.$ It is used in the linearized form,

$\begin{eqnarray*} k \partial_n T & = & 4 \varepsilon \sigma \left( \SField{T}_{\mathrm{env}}^3 \SField{T}-\SField{T}_{\mathrm{env}}^4 \right), \end{eqnarray*}$

when used for the linear heat equation.