using a run-time selectable preconditioner
References:
Van der Vorst, H. A. (1992).
Bi-CGSTAB: A fast and smoothly converging variant of Bi-CG
for the solution of nonsymmetric linear systems.
SIAM Journal on scientific and Statistical Computing, 13(2), 631-644.
Barrett, R., Berry, M. W., Chan, T. F., Demmel, J., Donato, J.,
Dongarra, J., Eijkhout, V., Pozo, R., Romine, C. & Van der Vorst, H.
(1994).
Templates for the solution of linear systems:
building blocks for iterative methods
(Vol. 43). Siam.
See also: https://en.wikipedia.org/wiki/Biconjugate_gradient_stabilized_method
Tests have shown that PBiCGStab with the DILU preconditioner is more
robust, reliable and shows faster convergence (~2x) than PBiCG with
DILU, in particular in parallel where PBiCG occasionally diverges.
This remarkable improvement over PBiCG prompted the update of all
tutorial cases currently using PBiCG to use PBiCGStab instead. If any
issues arise with this update please report on Mantis: http://bugs.openfoam.org
- There will be triangles rendered inside the mesh (when
surface-rendering), because one of the cell's triangles is defined
as a quadrangle in VTK_WEDGE.
- Therefore, this VTK_WEDGE representation is only used when
decomposing the mesh, otherwise the correct representation is done
by VTK_POLYHEDRON.
- Furthermore, using VTK_PYRAMID gave worse result, because it renders
2 triangles inside the mesh for the collapsed quadrangle, likely due
to mismatch with the adjacent cell's face.
- Using VTK_HEXAHEDRON was not tested in this iteration, given that it
should give even worse results, when compared to using VTK_PYRAMID.
Patch contributed by Bruno Santos
Resolves bug-report http://bugs.openfoam.org/view.php?id=2099
- "$FOAM_USER_APPBIN" and "$FOAM_USER_LIBBIN" have been added to
"foamOldDirs" in "etc/bashrc" and "etc/config.sh/unset"
- "$OPAL_PREFIX" is now undefined in the option "SYSTEMOPENMPI" within
"etc/config.sh/mpi", but only if the path defined in this variable
is cleaned when using "foamCleanPath".
- "$OPAL_PREFIX" is now also conditionally undefined in
"etc/config.sh/unset" when the path is picked up by "foamCleanPath".
Patch contributed by Bruno Santos
Resolved bug-report http://bugs.openfoam.org/view.php?id=2210
Description
An incompressible Casson non-Newtonian viscosity model.
References:
\verbatim
Casson, N. (1959).
Rheology of disperse systems.
In Proceedings of a Conference Organized by the
British Society of Rheology.
Pergamon Press, New York.
Fournier, R. L. (2011).
Basic transport phenomena in biomedical engineering.
CRC Press.
\endverbatim
Contributed by Sergey Sindeev
Description
Allows specification of different writing frequency of objects registered
to the database.
It has similar functionality as the main time database through the
\c writeControl setting:
- timeStep
- writeTime
- adjustableRunTime
- runTime
- clockTime
- cpuTime
It also has the ability to write the selected objects that were defined
with the respective write mode for the requested \c writeOption, namely:
- \c autoWrite - objects set to write at output time
- \c noWrite - objects set to not write by default
- \c anyWrite - any option of the previous two
Example of function object specification:
\verbatim
writeObjects1
{
type writeObjects;
libs ("libutilityFunctionObjects.so");
...
objects (obj1 obj2);
writeOption anyWrite;
}
\endverbatim
Patch contributed by Bruno Santos
Resolves bug-report http://bugs.openfoam.org/view.php?id=2090
