motionSmootherAlgoCheck::checkMesh is used by snappyHexMesh to check the mesh
after snapping and morphing. The minVol test which checks for collapsed cells
is now relative to the cube of the minimum bounding box length so that it is
less dependent on the size of the geometry and less likely to need changing for
very small geometries.
The default value is set in
etc/caseDicts/mesh/generation/meshQualityDict
etc/caseDicts/mesh/generation/meshQualityDict.cfg
//- Minimum cell pyramid volume relative to min bounding box length^3
// Set to a fraction of the smallest cell volume expected.
// Set to very negative number (e.g. -1e30) to disable.
minVol 1e-10;
The unused minArea and minTriangleTwist tests have been removed
The FOAM file format has not changed from version 2.0 in many years and so there
is no longer a need for the 'version' entry in the FoamFile header to be
required and to reduce unnecessary clutter it is now optional, defaulting to the
current file format 2.0.
A new run-time selectable interface compression scheme framework has been added
to the two-phase VoF solvers to provide greater flexibility, extensibility and
more consistent user-interface. The previously built-in interface compression
is now in the standard run-time selectable surfaceInterpolationScheme
interfaceCompression:
Class
Foam::interfaceCompression
Description
Interface compression corrected scheme, based on counter-gradient
transport, to maintain sharp interfaces during VoF simulations.
The interface compression is applied to the face interpolated field from a
suitable 2nd-order shape-preserving NVD or TVD scheme, e.g. vanLeer or
vanAlbada. A coefficient is supplied to control the degree of compression,
with a value of 1 suitable for most VoF cases to ensure interface integrity.
A value larger than 1 can be used but the additional compression can bias
the interface to follow the mesh more closely while a value smaller than 1
can lead to interface smearing.
Example:
\verbatim
divSchemes
{
.
.
div(phi,alpha) Gauss interfaceCompression vanLeer 1;
.
.
}
\endverbatim
The separate scheme for the interface compression term "div(phirb,alpha)" is no
longer required or used nor is the compression coefficient cAlpha in fvSolution
as this is now part of the "div(phi,alpha)" scheme specification as shown above.
Backward-compatibility is provided by checking the specified "div(phi,alpha)"
scheme against the known interface compression schemes and if it is not one of
those the new interfaceCompression scheme is used with the cAlpha value
specified in fvSolution.
More details can be found here:
https://cfd.direct/openfoam/free-software/multiphase-interface-capturing
Henry G. Weller
CFD Direct Ltd.
