and replaced pimpleDyMFoam with a script which reports this change.
The pimpleDyMFoam tutorials have been moved into the pimpleFoam directory.
This change is the first of a set of developments to merge dynamic mesh
functionality into the standard solvers to improve consistency, usability,
flexibility and maintainability of these solvers.
Henry G. Weller
CFD Direct Ltd.
The new momentum stress model selector class
compressibleInterPhaseTransportModel is now used to select between the options:
Description
Transport model selection class for the compressibleInterFoam family of
solvers.
By default the standard mixture transport modelling approach is used in
which a single momentum stress model (laminar, non-Newtonian, LES or RAS) is
constructed for the mixture. However if the \c simulationType in
constant/turbulenceProperties is set to \c twoPhaseTransport the alternative
Euler-Euler two-phase transport modelling approach is used in which separate
stress models (laminar, non-Newtonian, LES or RAS) are instantiated for each
of the two phases allowing for different modeling for the phases.
Mixture and two-phase momentum stress modelling is now supported in
compressibleInterFoam, compressibleInterDyMFoam and compressibleInterFilmFoam.
The prototype compressibleInterPhaseTransportFoam solver is no longer needed and
has been removed.
In this version of compressibleInterFoam separate stress models (laminar,
non-Newtonian, LES or RAS) are instantiated for each of the two phases allowing
for completely different modeling for the phases.
e.g. in the climbingRod tutorial case provided a Newtonian laminar model is
instantiated for the air and a Maxwell non-Newtonian model is instantiated for
the viscoelastic liquid. To stabilize the Maxwell model in regions where the
liquid phase-fraction is 0 the new symmTensorPhaseLimitStabilization fvOption is
applied.
Other phase stress modeling combinations are also possible, e.g. the air may be
turbulent but the liquid laminar and an RAS or LES model applied to the air
only. However, to stabilize this combination a suitable fvOption would need to
be applied to the turbulence properties where the air phase-fraction is 0.
Henry G. Weller, Chris Greenshields
CFD Direct Ltd.
Two boundary conditions for the modelling of semi-permeable baffles have
been added. These baffles are permeable to a number of species within
the flow, and are impermeable to others. The flux of a given species is
calculated as a constant multipled by the drop in mass fraction across
the baffle.
The species mass-fraction condition requires the transfer constant and
the name of the patch on the other side of the baffle:
boundaryField
{
// ...
membraneA
{
type semiPermeableBaffleMassFraction;
samplePatch membranePipe;
c 0.1;
value uniform 0;
}
membraneB
{
type semiPermeableBaffleMassFraction;
samplePatch membraneSleeve;
c 0.1;
value uniform 1;
}
}
If the value of c is omitted, or set to zero, then the patch is
considered impermeable to the species in question. The samplePatch entry
can also be omitted in this case.
The velocity condition does not require any special input:
boundaryField
{
// ...
membraneA
{
type semiPermeableBaffleVelocity;
value uniform (0 0 0);
}
membraneB
{
type semiPermeableBaffleVelocity;
value uniform (0 0 0);
}
}
These two boundary conditions must be used in conjunction, and the
mass-fraction condition must be applied to all species in the
simulation. The calculation will fail with an error message if either is
used in isolation.
A tutorial, combustion/reactingFoam/RAS/membrane, has been added which
demonstrates this transfer process.
This work was done with support from Stefan Lipp, at BASF.
XiEngineFoam is a premixed/partially-premixed combustion engine solver which
exclusively uses the Xi flamelet combustion model.
engineFoam is a general engine solver for inhomogeneous combustion with or
without spray supporting run-time selection of the chemistry-based combustion
model.
Standard crank-connecting rod and the new free-piston kinematics motion options
are provides, others can easily be added.
Contributed by Francesco Contino and Nicolas Bourgeois, BURN Research Group.
The new optional switch 'writeCyclicMatch' can be set to 'true' to enable the writing of
the cyclic match OBJ files; defaults to 'false'.
Patch contributed by Bruno Santos
Resolves patch request https://bugs.openfoam.org/view.php?id=2685
The combined solver includes the most advanced and general functionality from
each solver including:
Continuous phase
Lagrangian multiphase parcels
Optional film
Continuous and Lagrangian phase reactions
Radiation
Strong buoyancy force support by solving for p_rgh
The reactingParcelFoam and reactingParcelFilmFoam tutorials have been combined
and updated.
and the continuous-phase simulation type
For LTS and steady-state simulations the transient option does not need to be
provided as only steady-state tracking is appropriate. For transient running
the Lagrangian tracking may be steady or transient.
When an OpenFOAM simulation runs in parallel, the data for decomposed fields and
mesh(es) has historically been stored in multiple files within separate
directories for each processor. Processor directories are named 'processorN',
where N is the processor number.
This commit introduces an alternative "collated" file format where the data for
each decomposed field (and mesh) is collated into a single file, which is
written and read on the master processor. The files are stored in a single
directory named 'processors'.
The new format produces significantly fewer files - one per field, instead of N
per field. For large parallel cases, this avoids the restriction on the number
of open files imposed by the operating system limits.
The file writing can be threaded allowing the simulation to continue running
while the data is being written to file. NFS (Network File System) is not
needed when using the the collated format and additionally, there is an option
to run without NFS with the original uncollated approach, known as
"masterUncollated".
The controls for the file handling are in the OptimisationSwitches of
etc/controlDict:
OptimisationSwitches
{
...
//- Parallel IO file handler
// uncollated (default), collated or masterUncollated
fileHandler uncollated;
//- collated: thread buffer size for queued file writes.
// If set to 0 or not sufficient for the file size threading is not used.
// Default: 2e9
maxThreadFileBufferSize 2e9;
//- masterUncollated: non-blocking buffer size.
// If the file exceeds this buffer size scheduled transfer is used.
// Default: 2e9
maxMasterFileBufferSize 2e9;
}
When using the collated file handling, memory is allocated for the data in the
thread. maxThreadFileBufferSize sets the maximum size of memory in bytes that
is allocated. If the data exceeds this size, the write does not use threading.
When using the masterUncollated file handling, non-blocking MPI communication
requires a sufficiently large memory buffer on the master node.
maxMasterFileBufferSize sets the maximum size in bytes of the buffer. If the
data exceeds this size, the system uses scheduled communication.
The installation defaults for the fileHandler choice, maxThreadFileBufferSize
and maxMasterFileBufferSize (set in etc/controlDict) can be over-ridden within
the case controlDict file, like other parameters. Additionally the fileHandler
can be set by:
- the "-fileHandler" command line argument;
- a FOAM_FILEHANDLER environment variable.
A foamFormatConvert utility allows users to convert files between the collated
and uncollated formats, e.g.
mpirun -np 2 foamFormatConvert -parallel -fileHandler uncollated
An example case demonstrating the file handling methods is provided in:
$FOAM_TUTORIALS/IO/fileHandling
The work was undertaken by Mattijs Janssens, in collaboration with Henry Weller.
The calculation of the max and min limits are now only performed if required,
i.e. specified in fvSolution.
Also resolves bug-report https://bugs.openfoam.org/view.php?id=2566
See tutorials/compressible/rhoPimpleFoam/RAS/squareBendLiq for exapmle
pimpleControl: Added SIMPLErho option for running in SIMPLE mode
with large time-step/Courant number and relaxation. With this option the
density is updated from thermodynamics rather than continuity after the pressure
equation which is better behaved if pressure is relaxed and/or solved to a
loose relative tolerance. The need for this option is demonstrated in the
tutorials/compressible/rhoPimpleFoam/RAS/angledDuct tutorial which is unstable
without the option.
This tutorial demonstrates moving mesh and AMI with a Lagrangian cloud.
It is very slow, as interaction lists (required to compute collisions)
are not optimised for moving meshes. The simulation time has therefore
been made very short, so that it finishes in a reasonable time. The
mixer only completes a small fraction of a rotation in this time. This
is still sufficient to test tracking and collisions in the presence of
AMI and mesh motion.
In order to generate a convincing animation, however, the end time must
be increased and the simulation run for a number of days.
terms of the local barycentric coordinates of the current tetrahedron,
rather than the global coordinate system.
Barycentric tracking works on any mesh, irrespective of mesh quality.
Particles do not get "lost", and tracking does not require ad-hoc
"corrections" or "rescues" to function robustly, because the calculation
of particle-face intersections is unambiguous and reproducible, even at
small angles of incidence.
Each particle position is defined by topology (i.e. the decomposed tet
cell it is in) and geometry (i.e. where it is in the cell). No search
operations are needed on restart or reconstruct, unlike when particle
positions are stored in the global coordinate system.
The particle positions file now contains particles' local coordinates
and topology, rather than the global coordinates and cell. This change
to the output format is not backwards compatible. Existing cases with
Lagrangian data will not restart, but they will still run from time
zero without any modification. This change was necessary in order to
guarantee that the loaded particle is valid, and therefore
fundamentally prevent "loss" and "search-failure" type bugs (e.g.,
2517, 2442, 2286, 1836, 1461, 1341, 1097).
The tracking functions have also been converted to function in terms
of displacement, rather than end position. This helps remove floating
point error issues, particularly towards the end of a tracking step.
Wall bounded streamlines have been removed. The implementation proved
incompatible with the new tracking algorithm. ParaView has a surface
LIC plugin which provides equivalent, or better, functionality.
Additionally, bug report <https://bugs.openfoam.org/view.php?id=2517>
is resolved by this change.
except turbulence and lagrangian which will also be updated shortly.
For example in the nonNewtonianIcoFoam offsetCylinder tutorial the viscosity
model coefficients may be specified in the corresponding "<type>Coeffs"
sub-dictionary:
transportModel CrossPowerLaw;
CrossPowerLawCoeffs
{
nu0 [0 2 -1 0 0 0 0] 0.01;
nuInf [0 2 -1 0 0 0 0] 10;
m [0 0 1 0 0 0 0] 0.4;
n [0 0 0 0 0 0 0] 3;
}
BirdCarreauCoeffs
{
nu0 [0 2 -1 0 0 0 0] 1e-06;
nuInf [0 2 -1 0 0 0 0] 1e-06;
k [0 0 1 0 0 0 0] 0;
n [0 0 0 0 0 0 0] 1;
}
which allows a quick change between models, or using the simpler
transportModel CrossPowerLaw;
nu0 [0 2 -1 0 0 0 0] 0.01;
nuInf [0 2 -1 0 0 0 0] 10;
m [0 0 1 0 0 0 0] 0.4;
n [0 0 0 0 0 0 0] 3;
if quick switching between models is not required.
To support this more convenient parameter specification the inconsistent
specification of seedSampleSet in the streamLine and wallBoundedStreamLine
functionObjects had to be corrected from
// Seeding method.
seedSampleSet uniform; //cloud; //triSurfaceMeshPointSet;
uniformCoeffs
{
type uniform;
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
to the simpler
// Seeding method.
seedSampleSet
{
type uniform;
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
which also support the "<type>Coeffs" form
// Seeding method.
seedSampleSet
{
type uniform;
uniformCoeffs
{
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
}
Radiative heat transfer may now be added to any solver in which an energy
equation is solved at run-time rather than having to change the solver code.
For example, radiative heat transfer is now enabled in the SandiaD_LTS
reactingFoam tutorial by providing a constant/fvOptions file containing
radiation
{
type radiation;
libs ("libradiationModels.so");
}
and appropriate settings in the constant/radiationProperties file.
For example the porosity coefficients may now be specified thus:
porosity1
{
type DarcyForchheimer;
cellZone porosity;
d (5e7 -1000 -1000);
f (0 0 0);
coordinateSystem
{
type cartesian;
origin (0 0 0);
coordinateRotation
{
type axesRotation;
e1 (0.70710678 0.70710678 0);
e2 (0 0 1);
}
}
}
rather than
porosity1
{
type DarcyForchheimer;
active yes;
cellZone porosity;
DarcyForchheimerCoeffs
{
d (5e7 -1000 -1000);
f (0 0 0);
coordinateSystem
{
type cartesian;
origin (0 0 0);
coordinateRotation
{
type axesRotation;
e1 (0.70710678 0.70710678 0);
e2 (0 0 1);
}
}
}
}
support for which is maintained for backward compatibility.
For example the actuationDiskSource fvOption may now be specified
disk1
{
type actuationDiskSource;
fields (U);
selectionMode cellSet;
cellSet actuationDisk1;
diskDir (1 0 0); // Orientation of the disk
Cp 0.386;
Ct 0.58;
diskArea 40;
upstreamPoint (581849 4785810 1065);
}
rather than
disk1
{
type actuationDiskSource;
active on;
actuationDiskSourceCoeffs
{
fields (U);
selectionMode cellSet;
cellSet actuationDisk1;
diskDir (1 0 0); // Orientation of the disk
Cp 0.386;
Ct 0.58;
diskArea 40;
upstreamPoint (581849 4785810 1065);
}
}
but this form is supported for backward compatibility.
Main changes in the tutorial:
- General cleanup of the phaseProperties of unnecessary entries
- sensibleEnthalpy is used for both phases
- setTimeStep functionObject is used to set a sharp reduction in time step near the start of the injection
- Monitoring of pressure minimum and maximum
Patch contributed by Juho Peltola, VTT.
