Mesh Control Edges

Use for precise control of the mesh in specific regions of the geometry, without affecting the geometry used for assigning physics.

To fully resolve the gradients in a field in certain regions of a domain (2D) or on faces (3D), a finer mesh may be required. One way to avoid refining the mesh in the entire domain or face, is to partition it, then assign a finer mesh size to the domain or face created by the partitioning, as shown in Figure 7-35. By designating the created edges as a mesh control edges, they will only be visible in mesh mode, and only before the mesh is generated. As soon as the mesh is built in domains and faces adjacent to the mesh control edges, the designated edges are removed.

Figure 7-35: Edges highlighted in blue are designated as mesh control edges, which means that these edges are removed and are only available when building the mesh. The image on the right hand side shows the geometry after the Mesh control edges operation has been built, which is the geometry displayed in physics settings. The bottom image shows a mesh where the mesh control edges has made it possible to create a mapped mesh with edge distributions set to resolve the field in a GEC CCP reactor.

The operation removes a selection of edges that are isolated or that are adjacent to precisely two faces (in 3D) or two domains (in 2D, as shown in Figure 7-35). The edges act as a partitioning, and are removed from the geometry, but become available when you build the mesh. Use a mesh control edge to control the element size inside a domain, or to create a mapped mesh in regions, as shown below. Mesh control edges do not change the number of domains (2D) and edges displayed in the physics settings.

An advantage of working with mesh control edges is that when the edges have been removed, the mesher can move mesh vertices to make a smoother the size transition across the removed entities (see Figure 7-36). This behavior is controlled by the settings in the section of the mesh operation used to mesh the domains.

Figure 7-36: Comparing meshes where the Mesh control edges has been used vs. not used. The highlighted edge in the image to the left is added for the purpose of resolving the mesh in a region with steeper gradients. Designating the edge as a mesh control edge removes the edge and composes the two domains (2D) adjacent to the edge (upper right image). The lower right image shows the mesh if the edge is not marked as a mesh control edge. This means that the edge and domain partitioning are preserved. Compare the meshes on the right hand side to see the effect of smoothing the size transition across removed mesh control entities.

To use the operation, in the toolbar, from the menu (

), select (

). Then enter the properties of the operation using the following sections:

Input

Select the edges that you want to use for mesh control in the window. They then appear in the list. If the geometry sequence includes user-defined selections above the node, choose to select edges, or choose one of the selection nodes from the list next to .

Click the button to toggle between turning ON and OFF the selections.

Use the check box to specify if the operation also include the ignorable start and end vertices of the edge.

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With the CFD Module or Heat Transfer Module, see Stationary Incompressible Flow over a Backstep: Application Library path

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With the Battery Design Module, see Thermal Modeling of a Cylindrical Lithium-Ion Battery in 2D: Application Library path

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With the Semiconductor Module, see DC Characteristics of a MOS Transistor (MOSFET): Application Library path

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With the Plasma Module, see GEC CCP Reactor, Argon Chemistry: Application Library path

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