Adding Nonisothermal Flow Coupling in an Existing Model
The Heat Transfer Module provides the Nonisothermal Flow multiphysics feature. This feature can be added to a model containing a single-phase flow and a heat transfer interface. It is common to start a model with a single physics (for example, fluid flow), then implement the second one (for example, heat transfer). Then adding the Nonisothermal Flow multiphysics feature realizes the coupling between the two interfaces.
This multiphysics interface handles the two-way coupling. In addition, it accounts for the turbulence in the coupling. In particular, it modifies the effective thermal conductivity and implements thermal wall functions if the fluid flow model requires them. Those modifications affect the implementation of several heat transfer features. This multiphysics feature also redefines the consistent stabilization so that the multiphysics coupling effects are accounted for in the numerical stabilization. It allows to include work done by pressure changes and viscous dissipation, and Boussinesq approximation is supported. Finally some physics features are updated when the Nonisothermal Flow multiphysics feature is active. In particular, the Interior Fan and Screen fluid-flow features are updated to account for the multiphysics coupling.
Note that the physics interface settings may not be optimal for the numerical treatment of the coupling when the multiphysics feature is added afterward.