Surface-to-Ambient Radiation (Thin Layer, Thin Film, Fracture)
Use this subnode to add surface-to-ambient radiation to lines (geometrical edges in 3D or geometrical points in 2D and 2D axisymmetric) that represent thin boundaries of a thin layer, a thin film, or a fracture.
The net inward heat flux from surface-to-ambient radiation is
where ds is the layer thickness (replaced by df for a thin film, and by dfr for a fracture), ε is the surface emissivity, σ is the Stefan-Boltzmann constant (a predefined physical constant), and Tamb is the ambient temperature.
Surface-to-Ambient Radiation
Ambient temperature
For User defined, enter an Ambient temperature Tamb. The default value is approximately room temperature, 293.15 K (20 ºC). Else, select an Ambient temperature defined in the Ambient Settings section of a Heat Transfer or Heat Transfer in Shells interface.
Surface emissivity
The default Surface emissivity ε (a dimensionless number between 0 and 1) is taken From material. For User defined, it should be specified. An emissivity of 0 means that the surface emits no radiation at all while an emissivity of 1 means that it is a perfect blackbody.
Location in User Interface
Context menus
Heat Transfer in Solids>Thin Layer>Surface-to-Ambient Radiation
Heat Transfer in Solids>Thin Film>Surface-to-Ambient Radiation
Heat Transfer in Porous Media>Fracture>Surface-to-Ambient Radiation
Ribbon
Physics Tab with Thin Layer, Thin Film, or Fracture selected in the model tree:
Attributes>Surface-to-Ambient Radiation