Index

Thermal boundary condition along boundary i

Ver: 5
 

DESCRIPTION

For all non-isothermal problems, boundary conditions must be specified for the energy equation, in terms of Dirichlet (prescribed temperature) and/or Neumann (prescribed heat flux) conditions.

The type of thermal boundary condition on side i is selected in this menu together with the relevant parameters.

  OPTIONS
 
-2'  Enable flux postprocessor
Allows user to switch on the heat flux postprocessor on this boundary set
-2" Disable flux postprocessor
Allows user to switch off the heat flux postprocessor on this boundary set
-1 Upper level menu
The current thermal boundary conditions are accepted
0 Interface
Interface thermal boundary conditions are available for multidomain calculations. They require continuity of the temperature field along the interface. A jump can be prescribed for the heat flux ; this can be useful for thermal problems involving heat exchange by radiation.
Default : the heat flux is continuous.
1 Temperature imposed
Default : temperature vanishes
2 Flux density imposed
Heat flux can be defined as the sum of a constant flux, a convective and a radiative flux.
Default : the heat flux vanishes.
3 Insulated boundary / symmetry
Equivalent to option 2 with a vanishing heat flux.
This option can also be used as a symmetry boundary condition.
4 Inflow
Available if an inflow boundary condition has also been selected for the momentum equation on the same boundary set. A fully developed inlet temperature profile is calculated for the selected model.
5 Outflow
Vanishing heat flux imposed at the outlet
6 Flux for Fiber Spinning (not available in the standard version of Polyflow)
Boundary condition specially designed for axisymmetric fiber spinning simulations
7 Rosseland Correction
  Boundary condition specially designed for glass furnace simulations for which the radiation inside the molten glass must be taken into account
8 Inlet of periodic condition
Allows for defining symmetry or anti-symmetry constraints between two boundary sets
9 Outlet of periodic condition
Never directly available. Imposed via the  definition of a 'Inlet of periodic condition'
NOTES For inflow boundary conditions, fully developed temperature calculations are based on the assumption that all derivatives vanish in the normal direction to the inflow boundary.

For physical reasons, the boundaries adjacent to an inflow boundary should preferably be orthogonal to the inflow/outflow boundary.

  SEE ALSO