ThermalΒΆ

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.