The Diagonalize command is used to quickly create a new unstructured domain
derived from a pre-selected quad-dominant domain (structured or unstructured).
Furthermore, the command uses the same connectors bounding the pre-selected domain to
create the new unstructured domain based on the chosen diagonalization method.
The command becomes enabled once at least one quad-dominant domain (structured or
unstructured) is selected. Once this condition is met and the command is accessed, the
tools in the Diagonalize panel provide options for choosing the diagonalization
method, how/whether the new domains relate to the pre-selected domains, and whether the
pre-selected domains should remain visible, be hidden or be deleted.
Use the Diagonalize command to create unstructured domains
from existing quad-dominant domains.
The Diagonalization Method frame provides options for specifying how the
unstructured domains are created. There are four diagonalization methods to
- Aligned: Splits all the existing quadrilaterals in the same direction
throughout the domain. This method is only available if the selected domains are
- Best Fit: Splits the existing quadrilaterals such that the new
triangles have the smallest possible maximum included angle. This is the default
- Keep Quads: Keeps the current quadrilateral cells and transforms the
structured domain into an unstructured one. This method is only available if the
selected domains are structured.
- Initialize: Creates a new triangulated mesh using the default
initialization method for unstructured domains as defined in the
The Link command is used to create a linkage between a pre-selected structured
domain and the unstructured domain created from it via the Diagonalize
functionality. Once this option is checked on and the two domains are linked, any
change to their bounding connectors and/or to the pre-selected structured domain result
in both domains being updated in a consistent manner. This enables the unstructured
domain to retain its structured topology and the diagonalization method originally used
to create it. The Link checkbox becomes enabled when all of the pre-selected
domains are structured and the Delete option in the Visibility/Delete
Options frame is not selected.
Tip: Use the Link option to create unstructured domains
that retain a structured topology. This is useful anywhere a structured topology is
preferred, such as blunt trailing edges, because it allows the unstructured block
solver to diagonalize the surface quads to improve cell quality (if needed).
The link information is displayed next to the entity names in the List panel. As shown
in the figure below, the name of each linked domain is followed by paretheses containing
a link tag and the name of the linked domain.
Domain linkage is reflected in the names of the linked pair in the List panel. The
structured domain (dom-1) is shown with a dark gray background because it is currently
The Replace checkbox is used to automatically update the definition of all
unstructured blocks using the pre-selected domains to replace them with the newly created
unstructured domains. The Replace checkbox is enabled when at least one of the
pre-selected domains is used by at least one unstructured block.
The Visibility/Delete Options frame provides controls for how to treat the original
domains from which the new unstructured domains are created. By default the original
domains are hidden. Select Show to specify that the original
domains remain visible when you click OK to save and close the panel. Otherwise, use
Delete to have the original domains deleted when the panel closes.
Delete also disables the Link option in the Diagonalization