.. ############################################################################
.. manual/packages/vertex-cfd/boundary_condition_conduction.rst
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.. _sec_boundary_condition_conduction:

***********************************************
Boundary conditions for conduction model
***********************************************

Boundary conditions available for the conduction model are described below. Their usage in the `Data` sublist is illustrated through representative examples.

Adiabatic wall boundary
***********************
      
.. py:data:: Type

   :type: string
   :value: AdiabaticWall
   :usage: Required
   :description: Adiabatic wall boundary condition that sets :math:`\kappa \partial_n T = 0`.

.. literalinclude:: ../../../../examples/inputs/conduction/conduction_2d_heated_box.xml
   :language: xml
   :linenos:
   :lines: 81-83

Fixed/isothermal boundary
****************************************
      
.. py:data:: Type

   :type: string
   :value: Fixed
   :usage: Required
   :description: Fixed or isothermal boundary condition.

.. py:data:: temperature Value

   :type: double
   :value: :math:`(0,\infty]`
   :usage: Required
   :description: Constant temperature value in Kelvin :math:`(K)` to set at the boundary.

.. literalinclude:: ../../../../examples/inputs/conduction/conduction_2d_heated_box.xml
   :language: xml
   :linenos:
   :lines: 63-66

Heat flux boundary
******************

.. py:data:: Type

   :type: string
   :value: Fixed
   :usage: Required
   :description: Sets an uniform heat flux at the boundary.

.. py:data:: Flux Value

   :type: double
   :value: :math:`[-\infty,\infty]`
   :usage: Required
   :description: Heat flux value to set at the boundary :math:`W / m^2`.

.. literalinclude:: ../../../../examples/inputs/conduction/conduction_2d_heated_box.xml
   :language: xml
   :linenos:
   :lines: 72-75

Extrapolate boundary
***********************

.. py:data:: Type

   :type: string
   :value: Extrapolate
   :usage: Required
   :description: Set the boundary temperature and its gradient to the interior values.