Temperature, Interface (Heat Transfer in Shells Interface)
Use this node to specify the temperature on the exterior interfaces of a shell and, for the case of a layered shell, at the interfaces between its layers.
Boundary Selection
Select the boundaries on which to specify the temperature.
In addition, select the Restrict to layered boundaries check box to make the node applicable only if a layered material is defined on the boundary. If a layered material (Material with Layer thickness specified, Single Layer Material, Layered Material Link, or Layered Material Stack) is available, its name is then displayed beside the boundary index (for example, slmat1), otherwise the boundary is marked as not applicable.
Note that when the Shell type is Nonlayered shell in the Shells Properties section of the parent interface, the Restrict to layered boundaries check box is not editable.
Interface Selection
This section is available only when the Shell type is Layered shell in the Shells Properties section of the parent physics interface.
Set the interfaces for which the temperature should be prescribed. These can be internal interfaces between layers or the top and bottom surfaces.
The available options in the Apply to list are Top interface, Bottom interface, Exterior interfaces, Interior interfaces, All interfaces, and Selected interfaces. With the last option you can select any set of interfaces for a given layered material, by clearing the check boxes corresponding to layer interfaces where the node should not be applied in the Selection table. The top and bottom interfaces refer respectively to the upside and downside of the boundary, defined from the orientation of the normal vector. See Interface Selections for more details on the interfaces identification.
You can visualize the selected interfaces by clicking the Layer Cross Section Preview and Layer 3D Preview buttons.
•
For a general description of layer and interface selections, see Layer and Interface Selection Tools.
•
You can provide material parameters with a through-thickness variation by using expressions containing the extra dimension coordinate as described in Using the Extra Dimension Coordinates.
The desired selection for the node may correspond to boundaries with different layered materials.
See Layered Material, Layered Material Link, Layered Material Stack, Layered Material Link (Subnode), and Single Layer Materials in the COMSOL Multiphysics Reference Manual.
Upside and downside settings can be visualized by plotting the global normal vector (nx, ny, nz), that always points from downside to upside. Note that the normal vector (ht.nx, ht.ny, ht.nz) may be oriented differently.
See Tangent and Normal Variables in the COMSOL Multiphysics Reference Manual.
Temperature
For User defined, enter a value or expression for the Temperature T0. Else, select an Ambient temperature defined in an Ambient Properties node under Definitions.
The equation for this condition is T = T0 where T0 is the prescribed temperature.
Constraint Settings
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box.
The Constraint settings can be set to Pointwise constraints (default) or Weak constraints. Select Weak constraints to replace the standard constraints with a weak implementation.
•
Constraint Reaction Terms
•
Weak Constraints
•
Constraint Settings
You can specify a harmonic variation of the temperature value in a frequency domain analysis of perturbation type, by adding a Harmonic Perturbation subnode. See Theory for Harmonic Heat Transfer for more details.
Location in User Interface
Context Menus
Heat Transfer in Shells>Interfaces>Temperature, Interface
Heat Transfer in Films>Interfaces>Temperature, Interface
Heat Transfer in Fractures>Interfaces>Temperature, Interface
Ribbon
Physics tab with Heat Transfer in Shells selected in the model tree:
Boundaries>Temperature, Interface