Heat Flux (Thin Layer, Thin Film, Fracture)
Use this subnode to add heat flux across boundaries of a thin layer, a thin film or a fracture. A positive heat flux adds heat to the layer.
Edge Selection
Select the edges on which to apply the heat flux. The Restrict to layered edges check box makes the node applicable only if a layered material is defined on the edge. 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 edge index (for example, slmat1), otherwise the edge is marked as not applicable.
Note that when the Shell type is Nonlayered shell in the Shells Properties section of the parent node, the Restrict to layered boundaries check box is not editable.
In addition, in 2D, edges are modeled as points and this section is named Point Selection, containing a Restrict to layered points check box.
Shell Properties
Different settings are available, depending on the settings in the Shell Properties section of the parent node:
When the Shell type is Layered shell in the Shells Properties section of the parent node, the same layered material is used in the Heat Flux node. This option is not editable, but you can limit the contribution to individually selected layers by clearing the Use all layers check box. For a given Layered Material Link or Layered Material Stack, you get access to a list of check boxes for the selection of the individual layers.
When the Shell type is Nonlayered shell in the Shells Properties section of the parent interface, the Thickness is taken From parent feature in the Heat Flux node. You can change to User defined and override the parent node setting with a specific value or expression for Lth.
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.
Material Type
Select an option in the Material type list to specify if the inputs of the Heat Flux section are defined in the material or spatial frame:
The Solid option specifies that the heat flux q0 is defined in the material frame. Because the heat transfer variables and equations are defined in the spatial frame, the inputs are internally converted to the spatial frame. See Conversion Between Material and Spatial Frames for details.
The default option for the Heat Flux subnode is Nonsolid, which defines q0 in the spatial frame. No frame conversion is needed.
The From material option uses the option selected in the Material type list of the Material Properties section of the material applied on the domain on which the node is active.
Heat Flux
Click the General inward heat flux (default), Convective heat flux, or Heat rate (3D components only) button.
If General inward heat flux is selected, it adds q0 to the total flux across the selected edges. Enter a value for q0 to represent a heat flux that enters the layer. For example, any electric heater is well represented by this condition and its geometry can be omitted.
If Convective heat flux is selected, it adds q0 in the form q0 = h ⋅ (Text − T). Enter the Heat transfer coefficient h and the External temperature Text. This latter value depends on the geometry and the ambient flow conditions. For User defined, enter a value or expression. Else, select an Ambient temperature defined in an Ambient Properties node under Definitions.
3D Components: If Heat rate is selected, it adds q0 in the form q0 = P0 ⁄ A where A is equal to the area of the edge selection. Enter the heat rate P0.
Location in User Interface
Context Menus
Ribbon
Physics Tab with Thin Layer, Thin Film, or Fracture selected in the model tree: