<b>Create Mesh</b> menu. These hypotheses are actually changes in the
rules of mesh creation and as such don't possess adjustable values.
+\anchor non_conform_allowed_anchor
<h2>Non Conform mesh allowed hypothesis</h2>
<b>Non Conform mesh allowed</b> hypothesis allows to generate non-conform
meshes (that is, meshes having some edges ending on an edge or face of
adjacent elements).
+\anchor quadratic_mesh_anchor
<h2>Quadratic Mesh</h2>
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.
+edges are not straight but curved lines and can be defined by three
+points: first, middle and last instead of an ordinary two).
+\anchor propagation_anchor
<h2>Propagation of 1D Hypothesis on opposite edges</h2>
<b>Propagation of 1D Hypothesis on opposite edges</b> allows to propagate a
<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>
-This additional hypothesis can be used together with Quadrangle (Mapping) and Netgen 2D
-algorithms.
+This additional hypothesis can be used together with 2D triangulation algorithms.
+It allows 2D triangulation algorithms to build quadrangular meshes.
-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.
-<br>
-This hypothesis has one restriction on its work: the total quantity of
+When used with "Quadrangle (Mapping)" meshing algorithm, that is obsolete
+ since introducing \ref hypo_quad_params_anchor "Quadrangle parameters"
+hypothesis, 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).
-<h2>Triangle Preference</h2>
+\anchor viscous_layers_anchor
+<h2>Viscous Layers and Viscous Layers 2D</h2>
+
+<b>Viscous Layers</b> and <b>Viscous Layers 2D </b> additional
+hypotheses can be used together with some 3D algorithms, for example,
+Hexahedron(i,j,k) or 2D algorithms, for example, Triangle
+(MEFISTO), correspondingly. These hypotheses allow creation of layers
+of highly stretched elements, prisms in 3D and quadrilaterals in 2D,
+near mesh boundary, which is beneficial for high quality viscous
+computations.
+
+\image html viscous_layers_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>Faces (Edges) without layers</b> - defines geometrical faces
+ (or edges in 2D) on which element layers should not be
+ constructed. By default the element layers are not constructed on
+ geometrical faces shared by solids (and edges shared by faces in 2D).
+ \note A mesh shown in the 3D Viewer can prevent selection of faces
+ and edges, in this case just hide the mesh. 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).
+</li>
+</ul>
+
+\image html viscous_layers_mesh.png A group containing viscous layer prisms.
+
+<br><b>See also</b> a sample TUI script of a \ref tui_viscous_layers
+"Viscous layers construction".
-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.
-
*/
