The Heat Transfer with Surface-to-Surface Radiation (ht) interface (), found under the Radiation branch (), is used to model heat transfer by conduction, convection, and radiation, including surface-to-surface radiation.

A Solid model is active by default on all domains and when the Surface-to-surface radiation check box is selected for the Heat Transfer interface. All functionality to include other heat transfer models, such as Fluid, is also available. The radiosity equation defined on boundaries where surface-to-surface radiation is enabled corresponds to the radiosity method equation.

These default nodes are added to the Model Builder: Solid (with a default Opacity node, with Opacity set to Transparent), Thermal Insulation, and Initial Values. Then, from the Physics toolbar, add other nodes that implement, for example, boundary conditions. You can also right-click Heat Transfer with Surface-to-Surface Radiation to select physics features from the context menu.

When this physics interface is added, the Surface-to-surface radiation check box is selected by default, which enables the Radiation Settings section.

This section is available by clicking the Show button () and selecting Stabilization. See Consistent Stabilization for more details.

This section is available by clicking the Show button () and selecting Stabilization. See Inconsistent Stabilization for more details.

This section is available when the Surface-to-surface radiation check box is selected in the Physical Model section. See Radiation Settings for more details.

This section is available by clicking the Show button () and selecting Discretization. By default, the shape functions used for the temperature are Quadratic Lagrange. See Discretization for more details.

Select Linear (the default), Quadratic, Cubic, Quartic or Quintic to define the discretization level used for the Surface radiosity shape function.