Mapped

) to create a structured quadrilateral mesh on boundaries in 3D and domains in 2D. You can control the number, size, and distribution of elements using Size (only the Maximum element size parameter is used) and Distribution subnodes.

To create a mapped quadrilateral mesh for each domain, the mapped mesher maps a regular grid defined on a logical unit square onto each domain. The mapping method is based on transfinite interpolation. The settings in the Size and Distribution nodes used by a Mapped node determine the density of the logical meshes. For the mapping technique to work, the opposite sides of each logical unit square must be discretized by the same number of edge elements.

By default, the relationship between the four sides of the logical unit square and the boundaries around a domain is based on a criterion related to the sharpest angle between boundaries. If you want to control this relationship, right-click the node to add an Edge Groups subnode.

2D Mapped Mesh Geometry

For the 2D mapped meshing technique to work properly, the geometry must be reasonably regular. The following conditions must be satisfied:

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Each domain must be bounded by at least four boundary segments.

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Each domain must be bounded by only one connected boundary component (that is, no holes are allowed).

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The domains must not contain isolated or embedded vertices or boundary segments.

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The shape of each domain must not differ significantly from a rectangle.

For a geometry model that does not initially meet these criteria, it is usually possible to modify it so that a mapped mesh is generated, for example, by splitting it into simpler domains.

To create a mapped quadrilateral mesh:

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On the ribbon toolbar (Windows) from the (

) menu, choose .

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From the contextual toolbar (Mac and Linux), choose from the menu (

) (3D components) or click (2D components).

•

Right-click a node and choose . For 3D models, this is selected from the menu.

Then enter the properties for the mapped meshing operation using the following sections:

Boundaries (3D) / Domain Selection (2D)

Define the boundaries (3D) or domains (2D) where you want to create a mapped quad mesh. Choose the level of the geometry from the list:

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Choose to specify mapped quad mesh for remaining, unmeshed domains.

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Choose to create a mapped quad mesh in the entire geometry.

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Choose (3D) or (2D) to specify the geometric entities for which you want to create a mesh. Choose from the list to select the boundaries or domains in the window or choose (3D) or (2D) to select all boundaries or all domains.

Control Entities

Select the check box to smooth the transition in element size across removed control entities. You can specify the number of smoothing iterations in the field. In the field you can specify the maximum element depth, from the boundary layer interface, for the mesh points to be smoothed.

Advanced Settings

In 3D, you can choose between two different interpolation methods in the list. This specifies how the mapped meshing operation determines the positions of the interior mesh points. If you select , the positions of the interior mesh points are determined by transfinite interpolation in the 2D parameter space of the corresponding surface, and if you select , transfinite interpolation is done in 3D to determine these positions. Select to let the mapped meshing operation determine a suitable interpolation method automatically.

Select the check box to allow the mapped mesher to automatically adjust the mesh on edges that are not already meshed and where no explicit distribution is applied.


	For an example of a 2D mapped mesh, see Tubular Reactor with Nonisothermal Cooling Jacket: Application Library path COMSOL_Multiphysics/Chemical_Engineering/tubular_reactor.