The thermodynamic density field is now named "rho" by default and only renamed
"thermo:rho" by solvers that create and maintain a separate continuity density
field which is named "rho". This change significantly simplifies and
standardises the specification of schemes and boundary conditions requiring
density as it is now always named "rho" or "rho.<phase>" unless under some very
unusual circumstances the thermodynamic rather than continuity density is
required for a solver maintaining both.
The advantage of this change is particularly noticeable for multiphase
simulations in which each phase has its own density now named "rho.<phase>"
rather than "thermo:rho.<phase>" as separate phase continuity density fields are
not required so for multiphaseEulerFoam the scheme specification:
"div\(alphaRhoPhi.*,\(p\|thermo:rho.*\)\)" Gauss limitedLinear 1;
is now written:
"div\(alphaRhoPhi.*,\(p\|rho.*\)\)" Gauss limitedLinear 1;
For most multiphase flows it is more appropriate to evaluate the total pressure
from the static pressure obtained from p_rgh rather than from p_rgh directly.
Basic support is now provided for dynamic mesh redistribution, particularly for
load-balancing. The mesh distributor is selected in the optional 'distributor'
entry in dynamicMeshDict, for example in the
multiphase/interFoam/RAS/floatingObject tutorial case when run in parallel using
the new Allrun-parallel script
distributor
{
type decomposer;
libs ("libfvMeshDistributors.so");
redistributionInterval 10;
}
in which the 'decomposer' form of redistribution is selected to call the mesh
decomposition method specified in decomposeParDict to re-decompose the mesh for
redistribution. The redistributionInterval entry specifies how frequently mesh
redistribution takes place, in the above every 10th time-step. An optional
maxImbalance entry is also provided to control redistribution based on the cell
distribution imbalance:
Class
Foam::fvMeshDistributor::decomposer
Description
Dynamic mesh redistribution using the decomposer
Usage
Example of single field based refinement in all cells:
\verbatim
distributor
{
type decomposer;
libs ("libfvMeshDistributors.so");
// How often to redistribute
redistributionInterval 10;
// Maximum fractional cell distribution imbalance
// before rebalancing
maxImbalance 0.1;
}
\endverbatim
Currently mesh refinement/unrefinement and motion with redistribution is
supported but many aspects of OpenFOAM are not yet and will require further
development, in particular fvModels and Lagrangian.
Also only the geometry-based simple and hierarchical decomposition method are
well behaved for redistribution, scotch and ptScotch cause dramatic changes in
mesh distribution with a corresponding heavy communications overhead limiting
their usefulness or at least the frequency with which they should be called to
redistribute the mesh.
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.
