allows you to create a linear multigrid mesh with a specified number of levels. The node count is altered so that the number of elements on an edge is divisible by 2^M, where M is the number of multigrid levels. Thus, the new number of nodes will be:

where N is the current number of nodes.

You must select Blocking > Pre-Mesh Params > Update Sizes to for the change to take effect on a blocking with existing node distributions, or set this parameter before prescribing node counts or element sizes.

controls the projection of nodes. If the Projection limit is set to a non-zero value, P, the nodes along an edge within distance P of the end of the edge will not be projected. Instead, they will be linearly interpolated between the first point farther than P and the end. Nodes on the interior of a face within distance P of the edge of the face will not be projected. Instead, they will be linearly interpolated from the interior of the face. If the Projection limit is set to 0, all nodes will be projected.

The Projection limit is set to a non-zero value in cases where you want to keep the nodes on the edges and avoid projection to the underlying surfaces. This option is typically used for Navier-Stokes grids where the grid spacing is small relative to the geometry tolerance. Allowing nodes within a gap in the geometry to project would skew the elements. With a value P set to slightly larger than the gap, the nodes would instead be interpolated. The value may have to be set by trial and error depending on skewness or negative determinants being reported by pre-mesh quality checks.

specifies the default meshing law used for node distributions for edges. Edges which have a meshing law set will retain their current law unless Blocking > Pre-Mesh Params > Update Sizes is applied.

specifies the default node expansion ratio along an edge from either end of the edge.

specifies the range of Worst Blocks displayed by the Find Worst blocks option.

provides a smooth transition from the offset layer to interior layers. This option uses transfinite interpolation to prevent intermediate unprojected Ogrid splits from adversely affecting the smoothness of the mesh.

In the following figure, the cyan-colored Ogrid edge split, between the outer perimeter and the inner square, is not shaped for optimal mesh quality.

Figure 73: Ogrid Not Interpolated

This second figure shows the central Hgrid portion and the Ogrid split has been interpolated (shaped) to more smoothly transition the mesh across the model.

Figure 74: Ogrid, interpolated

is used when grid distribution on faces is independent of the sub-edge structure. It also helps to turn on this option if a series of block splits have been made where the splits do not extend through the whole topology. With this option, subsequent splits would not "connect" to previous non-extended splits.

projects the mesh to the true Bspline geometry rather than the faceted representation, which is the internal triangulated representation of surface data as defined by Settings > Model > Triangulation Tolerance. This can be used instead of decreasing the tri-tolerance or using projection limit, where small gaps in the faceted representation create skewed elements on a Navier-Stokes grid. This, however, takes longer and more memory to compute the pre-mesh.

checks the internal block data structures for inconsistencies and fixes them if possible.

checks for all the inverted (left-handed) blocks and redefines the block by reordering the vertices to make it right-handed.

when enabled (by default this option is disabled), converts degenerate 7-noded-hexas (2 nodes merged along an edge) into two pyramids when you select the Convert to Unstruct Mesh option under Blocking > Pre-Mesh in the Model tree or when using the File > Blocking > Save Unstructured Mesh option.

when enabled, allows a hexa face to be projected to an underlying surface. Default is off meaning the hexa face will be projected to a face family.

When two surfaces are very close to each other and highly curved, family based projection may cause the nodes to jump between surfaces.

displays additional minor warning messages that are intended to aid development or support in diagnosing possible problems that may occur. This option is disabled by default, but warnings intended to help the user with errors or problems are always displayed.

when enabled, this option allows the previously saved hexa settings to be overwritten by the settings from the loaded blocking file. When disabled, the previously saved hexa settings will be retained and the settings in the loaded file will be ignored. This option is enabled by default.

Transfinite interpolation is used for face interpolation when computing a mesh. The default is linear but quadratic is better for maintaining initial element heights. The drawback is that it can produce inverted elements in bowtie-shaped blocks where linear would work fine.

specifies the name of another blocking topology that you can use to test different smooth mesh options. The next time you re-compute the premesh, node positions will be matched to those in the reference topology.

For example, you set a reference topology based on a smoothed Euler mesh. If you now modify the mesh to have Navier Stokes spacing while maintaining the blocking topology, the node positions in the NS elements will match those in the smoothed Euler elements, giving you a smooth mesh but with the NS spacing.

specifies the default mesh type that will be used for meshing unstructured 2D surface blocking. The following options are available:

specifies the method that will be used for meshing unstructured 2D surface blocking. The following options are available:

specifies the entities or blocks to mesh for Blocking Tree > Pre-Mesh. Used typically for blocks with a mixture of mapped (structured), swept, and free (fully unstructured) 3D blocks as encountered using Multizone techniques.

specifies the number of Tetra smoothing steps for Multizone unstructured blocks. You may want to lower this during early iterations of Multizone blocks in order to save time.

restores the hexa meshing settings to the defaults.