By default, a Delaunay based method is used to insert points into an unstructured
domain when it is initialized. Alternatively, you may
select the Advancing Front, Advancing Front Ortho, or Thin Surface
The Algorithm pull-down provides additional methods for filling the isotropic portion
of the domain.
The Algorithm pull-down provides a choice of four methods for filling the isotropic
portion of the domain:
- Delaunay: Fills the interior of the domain with isotropic cells (triangles
or triangles and quads) using a modified Delaunay approach. Delaunay
is the default option for Algorithm.
- Advancing Front: Fills the interior of the domain with isotropic cells
(triangles or triangles and quads) using an advancing front approach. When Cell Types
is set to Triangles, Advancing Front produces equilateral triangles that are
more uniform in appearance than Delaunay.
- Advancing Front Ortho: Fills the interior of the domain with right-angled
isotropic cells (triangles or triangles and quads) using an advancing quad approach.
- Thin Surface Interpolation:
Fills the interior of the domain with cells (triangles or triangles and quads)
with a more structured-like appearance than can be achieved using Advancing Front or
Advancing Front Ortho, without strictly requiring the domain to be
computationally balanced or linked to a structured domain.
Thin Surface Interpolation is intended to be used on long thin rectangular
surfaces (such as the blunt trailing edge of a wing), where using diagonalized
structured domains is not possible or practical. Similar to structured domains, T-Rex is not
available for domains using Thin Surface Interpolation and source influence only
affects the spacing distribution on the bounding connectors.
Caution: Since Thin Surface Interpolation is intended as an
alternative to structured domain initialization, the attributes in the
T-Rex tab, and
Size Field tab have no impact.
However, these attributes are used with the
Advancing Front Ortho algorithm if
Thin Surface Interpolation fails due to one of the constraints below.
Additionally, Thin Surface
Interpolation can only be applied to domains that meet certain constraints, otherwise the
algorithm defaults to Advancing Front Ortho and a warning message is printed to the
Messages window. Please click the Thin Surface Interpolation Constraints
button below to view a table listing the constraints and their meanings.
The figure below shows a comparison of the grid characteristics produced by the four
algorithms using both the Triangles and Triangles and Quads cell type options.
Note the differences between the Advancing Front Ortho and Thin Surface
Interpolation algorithms when using computationally unbalanced domains.
The Delaunay, Advancing Front, Advancing Front Ortho, and Thin Surface Interpolation algorithms
produce surface grids with very distinct characteristics.