The Heat Transfer in Films Interface
The Heat Transfer in Films (htlsh) interface (), found in the Thin Structures physics area under the Heat Transfer branch (), is used to model heat transfer by conduction, convection and radiation in layered materials represented by boundaries. The interface is active on all boundaries where a layered material is defined, with a Fluid model active by default. All functionalities for including other boundary contributions, such as surface-to-ambient radiation, are also available.
Although the layered material is represented as a boundary in the model, the through-thickness variation of the temperature is accounted for. It means that the convection-diffusion equation is solved also in the layered material’s thickness direction. In addition, a single boundary may represent several layers with different thermal properties varying through the thickness of the layered material.
The physics interface is available for 2D components, 3D components, and for axisymmetric components with cylindrical coordinates in 2D.
When this version of the physics interface is added, these default nodes are also added to the Model Builder: Fluid, Thermal Insulation (an edge condition), and Initial Values. Then, from the Physics toolbar, add additional nodes that implement, for example, boundary interface or edge conditions, and heat sources. You can also right-click Heat Transfer in Films to select physics features from the context menu.
Layer Selection
Select the applicable layers (the default setting is All layered materials) on which to apply the interface.
If no layered materials have been included yet, there is a shorthand available for creating a Single Layer Material, a Layered Material Link, or a Layered Material Stack (the plus, next to the Layered Material list).
When a layered material stack or link is selected from the Layered Material list, unselect the check boxes corresponding to layers where the interface should not be applied in the Selection table.
You can visualize the selected layered materials and layers in each layered material by clicking the Layer cross section preview and Layer 3D preview buttons.
The desired selection for the physics interface may correspond to boundaries with different layered materials. The All layered materials option allows to gather these materials to make the desired selection applicable for the physics interface on the union of the boundaries where the layered materials are defined.
See Layered Material, Layered Material Link, Layered Material Stack, Layered Material Link (Subnode), and Single Layer Material in the COMSOL Multiphysics Reference Manual for details on the definition of layered materials.
Physical Model
By default, the Heat transfer in porous media check box is not selected under the Physical Model section. Select it to make the Porous Medium boundary feature available.
Consistent Stabilization
This section is available by clicking the Show button () and selecting Stabilization. See Consistent Stabilization for more details.
Inconsistent Stabilization
This section is available by clicking the Show button () and selecting Stabilization. See Inconsistent Stabilization for more details.
Discretization
This section is available by clicking the Show button () and selecting Discretization.
Temperature
By default, the shape functions used for the temperature are Linear. This setting affects also the discretization of the temperature field in the thickness direction.
See Discretization for more details.
Dependent Variables
See Dependent Variables for details.
See Settings for the Heat Transfer in Shells Interface for a description of the other settings.