Additional Hypotheses can be applied as a supplement to the main hypotheses, introducing additional concepts to mesh creation.
To define an Additional Hypothesis simply select it in Create Mesh menu. These hypotheses are actually changes in the rules of mesh creation and as such don't possess adjustable values.
Non Conform mesh allowed hypothesis allows to generate non-conform meshes (that is, meshes having some edges ending on an edge or face of adjacent elements).
Quadratic Mesh hypothesis allows to build a quadratic mesh (whose edges are not straight but broken lines and can be defined by three points: first, middle and last) instead of an ordinary one.
Propagation of 1D Hypothesis on opposite edges allows to propagate a hypothesis onto an opposite edge. If a local hypothesis and propagation are defined on an edge of a quadrangular face, the opposite edge will have the same hypothesis, unless another hypothesis has been locally defined on the opposite edge.
See Also a sample TUI Script of a Propagation hypothesis operation
This additional hypothesis can be used together with Quadrangle (Mapping) and Netgen 2D algorithms.
It allows Netgen 2D to build quadrangular meshes at any conditions.
It allows Quadrangle (Mapping) to build quadrangular meshes even if the number of nodes at the opposite edges of a meshed face is not equal, otherwise this mesh will contain some triangular elements. This use case is obsolete now. Use Quadrangle Parameters hypothesis with type Quadrangle Preference set instead.
This hypothesis has one restriction on its work: the total quantity of segments on all four sides of the face must be even (divisible by 2).
This additional hypothesis can be used only together with Quadrangle (Mapping) algorithm. It allows to build triangular mesh faces in the refinement area if the number of nodes at the opposite edges of a meshed face is not equal, otherwise refinement area will contain some quadrangular elements. This hypothesis is obsolete now. Use Quadrangle Parameters hypothesis with type Triangle Preference set instead.
Viscous Layers additional hypothesis can be used together with several 3D algorithms: NETGEN 3D, GHS3D and Hexahedron(i,j,k). This hypothesis allows creation of layers of highly stretched prisms near mesh boundary, which is beneficial for high quality viscous computations. The prisms constructed on the quadrangular mesh faces are actually the hexahedrons.
A group containing viscous layer prisms.
See also a sample TUI script of a Viscous layers construction.
