<br><b>See Also</b> a sample TUI Script of a
\ref tui_propagation "Propagation hypothesis" operation
+\anchor propagofdistribution_anchor
+<h2>Propagation of Node Distribution on Opposite Edges</h2>
+
+<b>Propagation of Node Distribution on Opposite Edges</b> allows to propagate
+distribution of nodes 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 number of nodes and the same
+relations between segment lengths, unless another hypothesis
+has been locally defined on the opposite edge.
+
+<br><b>See Also</b> a sample TUI Script of a
+\ref tui_propagation "Propagation hypothesis" operation
+
\anchor quadrangle_preference_anchor
<h2>Quadrangle Preference</h2>
\image html viscous_layers_hyp.png
+\image html viscous_layers_2d_hyp.png
+
<ul>
<li><b>Name</b> - allows to define the name of the hypothesis.</li>
<li><b>Total thickness</b> - gives the total thickness of element layers.</li>
<li><b>Number of layers</b> - defines the number of element layers.</li>
<li><b>Stretch factor</b> - defines the growth factor of element height
from the mesh boundary inwards.</li>
-<li><b>Specified Edges are</b> - defines how the shapes specified by
+<li><b>Extrusion method</b> (available in 3D only) - defines how
+ position of nodes are found during prism construction and how
+ creation of distorted and intersecting prisms is prevented.
+<ul><li><b>Surface offset + smooth</b> method extrudes nodes along normal
+ to underlying geometrical surface. Smoothing of internal surface of
+ element layers is possible to avoid creation of invalid prisms.</li>
+ <li><b>Face offset</b> method extrudes nodes along average normal of
+ surrounding mesh faces till intersection with a neighbor mesh face
+ translated along its own normal by the layers thickness. Thickness
+ of layers can be limited to avoid creation of invalid prisms.</li>
+ <li><b>Node offset</b> method extrudes nodes along average normal of
+ surrounding mesh faces by the layers thickness. Thickness of
+ layers can be limited to avoid creation of invalid prisms.</li>
+\image html viscous_layers_extrusion_method.png "Prisms created by the tree extrusion methods at the same other parameters"
+</ul></li>
+<li><b>Specified Faces/Edges are</b> - defines how the shapes specified by
the next parameter are used.
-<li><b>Faces without layers</b> and <b>Edges with/without layers</b> -
- in the 3D case it defines geometrical faces on which element layers
- should not be constructed; in the 2D case it defines geometrical edges
- on which element layers either should be or should not be
- constructed, depending on the value of the previous parameter
- (<b>Specified Edges are</b>).
+<li><b> Faces/Edges with/without layers</b> -
+ defines geometrical faces or edges on which element layers
+ either should be or should not be constructed, depending on the
+ value of the previous parameter (<b>Specified Faces/Edges are</b>).
+ Faces (or edges) can be selected either in the Object Browser or in
+ the VTK Viewer.
\note A mesh shown in the 3D Viewer can prevent selection of faces
- and edges, just hide the mesh to avoid this. To avoid a long wait when a
+ and edges, just hide the mesh to avoid this. Sometimes a face to
+ select is hidden by other faces, in this case consider creating a
+ group of faces you want to select in the Geometry module.<br>
+ To avoid a long wait when a
geometry with many faces (or edges) is displayed, the number of faces
(edges) shown at a time is limited by the value of "Sub-shapes
- preview chunk size" preference (in Preferences/Mesh/General tab).<br>
-
- Whatever shapes are specified by this
- parameter, the element layers are not constructed on geometrical
- faces shared by several solids in 3D case and edges shared by
- several faces in 2D case. In other words the element layers can be
- constructed on boundary faces and edges, and are not constructed on
- internal faces and edges. There is an exception to this rule in 2D
- case: if "Viscous Layers 2D" hypothesis is assigned to a sub-mesh,
- the element layers can be constructed on boundary edges of the shape
- of this sub-mesh.
+ preview chunk size" preference (in Preferences/Mesh/General tab).
+
+
+ If faces/edges without layers are specified, the element layers are
+ not constructed on geometrical faces shared by several solids in 3D
+ case and edges shared by several faces in 2D case. In other words,
+ in this mode the element layers can be constructed on boundary faces
+ and edges only, and are not constructed on internal faces and
+ edges. There is an exception to this rule: if a hypothesis is
+ assigned to a sub-mesh, the element layers can be constructed on
+ boundary faces/edges of the shape of this sub-mesh, at same time
+ possibly being internal faces/edges within the whole model.
\image html viscous_layers_on_submesh.png 2D viscous layers constructed on boundary edges of a sub-mesh on a disk face.
+ If you use \b several hypotheses to define viscous layers on faces of
+ one solid, keep in mind the following. Each hypothesis defines a set
+ of faces with viscous layers (even if you specify faces without
+ layers). The sets of faces with viscous layers defined by several
+ hypotheses should not intersect, else the module won't add an
+ hypothesis that is incompatible with another one. <br>
+ Also you can't define different number of layers on adjacent faces
+ of a solid.<br>
+ This logic is also valid for the 2D hypothesis.
</li>
</ul>
<br><b>See also</b> a sample TUI script of a \ref tui_viscous_layers
"Viscous layers construction".
-
*/
