Diffuse Surface

Use the Diffuse Surface condition to add radiation to boundaries.

Radiation Settings

To display this section, click the Show button () and select Advanced Physics Options.

Select a Radiation direction based on the geometric normal (nx, ny, nz)—Negative normal direction or Positive normal direction (the default).

This setting has no effect unless the temperature differs from one side of the boundary to the other.

Ambient

Enter an Ambient temperature Tamb (SI unit: K). The default is 293.15 K.

Surface Emissivity

The default Surface emissivity ε (a dimensionless number between 0 and 1) is taken From material. An emissivity of 0 means that the surface emits no radiation at all and an emissivity of 1 means that it is a perfect blackbody. For User defined enter a different value. Default value is 0.

Location in User Interface

Context menus
Heat Transfer in Solids>Radiation>Diffuse_Surface
Heat Transfer in Fluids>Raudation>Diffuse_Surface

Ribbon

Physics Tab with interface as Heat Transfer in Solids or Heat Transfer in Fluids selected:
Boundaries>Radiation>Diffuse_Surface