Free Quad
Add a Free Quad node () to create an unstructured quadrilateral mesh on boundaries in 3D and domains in 2D. You can control the number, size, and distribution of elements by using Size and Distribution nodes.
To create an unstructured quadrilateral mesh:
In the Mesh ribbon toolbar (Windows), from the Generators>Boundary () menu choose Free Quad.
From the Mesh contextual toolbar (macOS and Linux), choose Free Quad from the Boundary menu () (3D components) or click Free Quad (2D components).
Right-click a Mesh node and choose Free Quad. For 3D components, this is selected from the More Operations> menu.
Then enter the properties for the quadrilateral meshing operation using the following sections:
Boundaries (3D) / Domains (2D)
Define the boundaries (3D) or domains (2D) where you want to create an unstructured quad mesh. Choose the level of the geometry from the Geometric entity level list:
Choose Remaining to specify unstructured quad mesh for remaining, unmeshed domains.
Choose Entire geometry to create an unstructured quad mesh in the entire geometry.
Choose Boundary (3D) or Domain (2D) to specify the geometric entities for which you want to create an unstructured quad mesh. Choose Manual in the Selection list to select the boundaries or domains in the Graphics window or choose All boundaries (3D) or All domains (2D) to select all boundaries or all domains.
Scale Geometry
To scale the geometry during the meshing operation, change the x-scale, y-scale, and z-scale in 3D to positive real numbers. If any of the scale factors are not equal to one, the software scales the geometry in the x, y, and z directions before meshing; after meshing, it restores the geometry and mesh to fit the original size. The scale factors make it possible to generate meshes that are anisotropic. They are also useful if the mesh generator creates many elements due to a thin geometry or if the mesh generation fails due to large aspect ratios in the geometry.
Control Entities
Select the Smooth across removed control entities check box to smooth the transition in element size across removed control entities. You can specify the number of smoothing iterations in the Number of iterations field. In the Maximum element depth to process field you can specify the maximum element depth, from the boundary layer interface, for the mesh points to be smoothed.
Tessellation
From the Method list, choose the tessellation method to use for creating an unstructured quadrilateral mesh:
Select Automatic (the default) to make the mesh generator determine the best algorithm to use for each domain.
Select Legacy version 5.2 to use the algorithm available in version 5.2 and earlier versions of COMSOL Multiphysics.
Select Legacy version 5.2a to use the algorithm available in version 5.2a of COMSOL Multiphysics, which, in addition to earlier versions of the free quad algorithm, has support for templates.