When the predefined Local Thermal Nonequilibrium interface () is added (found under the Heat Transfer branch () of the Model Wizard or Add Physics windows), it combines the Heat Transfer in Solids and the Heat Transfer in Fluids interfaces to model heat transfer in porous media for which the solid and fluid temperatures are not in equilibrium.

As a predefined multiphysics coupling, Heat Transfer in Solids and Heat Transfer in Fluids interfaces are added to the Model Builder. In addition, a Multiphysics node is added, which automatically includes the multiphysics coupling feature Local Thermal Nonequilibrium.

The Heat Transfer in Solids interface provides features for modeling heat transfer by conduction, convection, and radiation. A Solid model is active by default on all domains.

The Heat Transfer in Fluids interface provides features for modeling heat transfer by conduction, convection, and radiation. A Fluid model is active by default on all domains.