Thin Layer

This node defines the thermal conductivity and thermodynamics properties of a resistive material located on internal or external boundaries. This material can be formed of one or more layers.

When the layer is a bad thermal conductor compared to the adjacent geometry, the tangential heat flux can be neglected and only the heat flux across the layer’s thickness is considered. The layer can be constituted of multiple sublayers with specific thickness and thermal properties. This condition may also be used to enforce consistent initial conditions.

Layer Selection

Select the applicable layers (the default setting is ) defining the required material properties for the node.

If no layered materials have been included yet, there is a shorthand available for creating a , a , or a (the plus, next to the list).

When a layered material stack or link is selected from the list, clear the check boxes corresponding to layers where the node should not be applied in the table.

You can visualize the selected layered materials and layers in each layered material by clicking the and buttons.


	The desired selection for the node 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 node 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 Materials in the COMSOL Multiphysics Reference Manual.

Model Input

This section has fields and values that are inputs to expressions that define material properties. If such user-defined property groups are added, the model inputs appear here.

Volume reference temperature

This section is available when a temperature-dependent density defined in a material is used. On the material frame, the density is evaluated onto a reference temperature to ensure mass conservation in the presence of temperature variations. By default the is used. This corresponds to the variable minput.Tempref, which is set by default to 293.15 K. To edit it, click the button (

), and in the node under , set a value for the in the section.

The other options are and all temperature variables from the physics interfaces included in the model.


	This model input does not override the Reference temperature Tref set in the Physical Model section of the physics interface, and that is used to evaluate the reference enthalpy, and a reference density for incompressible nonisothermal flows.

Temperature

This section is available when temperature-dependent material properties are used. By default the temperature of the parent interface is used and the section is not editable. To edit the field, click (

). The available options are (default), (the minput.T variable, set to 293.15 K by default), and all temperature variables from the physics interfaces included in the model. To edit the minput.T variable, click the button (

), and in the node under , set a value for the in the section.

Layer Model

The only option for is .

From the list select (the default) or , to set either the k or the Rs.

Heat Conduction

The default k is taken . For select , , , or to enter another value or expression.

Alternatively, set a value for the Rs if is set to in the section.

Thermodynamics

By default the ρ and Cp of the layer are taken . For enter other values or expressions. These properties are only used in time-dependent studies, but must be set in all cases.

Location in User Interface

Context menus

Ribbon

Physics Tab with interface as , , or selected: