Mesh motion and topology change are now combinable run-time selectable options
within fvMesh, replacing the restrictive dynamicFvMesh which supported only
motion OR topology change.
All solvers which instantiated a dynamicFvMesh now instantiate an fvMesh which
reads the optional constant/dynamicFvMeshDict to construct an fvMeshMover and/or
an fvMeshTopoChanger. These two are specified within the optional mover and
topoChanger sub-dictionaries of dynamicFvMeshDict.
When the fvMesh is updated the fvMeshTopoChanger is first executed which can
change the mesh topology in anyway, adding or removing points as required, for
example for automatic mesh refinement/unrefinement, and all registered fields
are mapped onto the updated mesh. The fvMeshMover is then executed which moved
the points only and calculates the cell volume change and corresponding
mesh-fluxes for conservative moving mesh transport. If multiple topological
changes or movements are required these would be combined into special
fvMeshMovers and fvMeshTopoChangers which handle the processing of a list of
changes, e.g. solidBodyMotionFunctions:multiMotion.
The tutorials/multiphase/interFoam/laminar/sloshingTank3D3DoF case has been
updated to demonstrate this new functionality by combining solid-body motion
with mesh refinement/unrefinement:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: dev
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
location "constant";
object dynamicMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
mover
{
type motionSolver;
libs ("libfvMeshMovers.so" "libfvMotionSolvers.so");
motionSolver solidBody;
solidBodyMotionFunction SDA;
CofG (0 0 0);
lamda 50;
rollAmax 0.2;
rollAmin 0.1;
heaveA 4;
swayA 2.4;
Q 2;
Tp 14;
Tpn 12;
dTi 0.06;
dTp -0.001;
}
topoChanger
{
type refiner;
libs ("libfvMeshTopoChangers.so");
// How often to refine
refineInterval 1;
// Field to be refinement on
field alpha.water;
// Refine field in between lower..upper
lowerRefineLevel 0.001;
upperRefineLevel 0.999;
// Have slower than 2:1 refinement
nBufferLayers 1;
// Refine cells only up to maxRefinement levels
maxRefinement 1;
// Stop refinement if maxCells reached
maxCells 200000;
// Flux field and corresponding velocity field. Fluxes on changed
// faces get recalculated by interpolating the velocity. Use 'none'
// on surfaceScalarFields that do not need to be reinterpolated.
correctFluxes
(
(phi none)
(nHatf none)
(rhoPhi none)
(alphaPhi.water none)
(meshPhi none)
(meshPhi_0 none)
(ghf none)
);
// Write the refinement level as a volScalarField
dumpLevel true;
}
// ************************************************************************* //
Note that currently this is the only working combination of mesh-motion with
topology change within the new framework and further development is required to
update the set of topology changers so that topology changes with mapping are
separated from the mesh-motion so that they can be combined with any of the
other movements or topology changes in any manner.
All of the solvers and tutorials have been updated to use the new form of
dynamicMeshDict but backward-compatibility was not practical due to the complete
reorganisation of the mesh change structure.
A new constraint patch has been added which permits AMI coupling in
cyclic geometries. The coupling is repeated with different multiples of
the cyclic transformation in order to achieve a full correspondence.
This allows, for example, a cylindrical AMI interface to be used in a
sector of a rotational geometry.
The patch is used in a similar manner to cyclicAMI, except that it has
an additional entry, "transformPatch". This entry must name a coupled
patch. The transformation used to repeat the AMI coupling is taken from
this patch. For example, in system/blockMeshDict:
boundary
(
cyclic1
{
type cyclic;
neighbourPatch cyclic2;
faces ( ... );
}
cyclic2
{
type cyclic;
neighbourPatch cyclic1;
faces ( ... );
}
cyclicRepeatAMI1
{
type cyclicRepeatAMI;
neighbourPatch cyclicRepeatAM2;
transformPatch cyclic1;
faces ( ... );
}
cyclicRepeatAMI2
{
type cyclicRepeatAMI;
neighbourPatch cyclicRepeatAMI1;
transformPatch cyclic1;
faces ( ... );
}
// other patches ...
);
In this example, the transformation between cyclic1 and cyclic2 is used
to define the repetition used by the two cyclicRepeatAMI patches.
Whether cyclic1 or cyclic2 is listed as the transform patch is not
important.
A tutorial, incompressible/pimpleFoam/RAS/impeller, has been added to
demonstrate the functionality. This contains two repeating AMI pairs;
one cylindrical and one planar.
A significant amount of maintenance has been carried out on the AMI and
ACMI patches as part of this work. The AMI methods now return
dimensionless weights by default, which prevents ambiguity over the
units of the weight field during construction. Large amounts of
duplicate code have also been removed by deriving ACMI classes from
their AMI equivalents. The reporting and writing of AMI weights has also
been unified.
This work was supported by Dr Victoria Suponitsky, at General Fusion
