Most fvOptions change the state of the fields and equations they are applied to
but do not change internal state so it makes more sense that the interface is
const, consistent with MeshObjects. For the few fvOptions which do maintain a
changing state the member data is now mutable.
The new optional 'slash' scoping syntax is now the default and provides a more
intuitive and flexible syntax than the previous 'dot' syntax, corresponding to
the common directory/file access syntax used in UNIX, providing support for
reading entries from other dictionary files.
In the 'slash' syntax
'/' is the scope operator
'../' is the parent dictionary scope operator
'!' is the top-level dictionary scope operator
Examples:
internalField 3.4;
active
{
type fixedValue;
value.air $internalField;
}
inactive
{
type anotherFixedValue;
value $../active/value.air;
anotherValue $!active/value.air;
sub
{
value $../../active/value.air;
anotherValue $!active/value.air;
}
}
"U.*"
{
solver GAMG;
}
e.air
{
$U.air;
}
external
{
value $testSlashDict2!active/value.air;
}
active2
{
$testSlashDict2!active;
}
If there is a part of the keyword before the '!' then this is taken to be the
file name of the dictionary from which the entry will be looked-up using the
part of the keyword after the '!'. For example given a file testSlashDict containing
internalField 5.6;
active
{
type fixedValue;
value.air $internalField;
}
entries from it can be read directly from another file, e.g.
external
{
value $testSlashDict2!active/value.air;
}
active2
{
$testSlashDict2!active;
}
which expands to
external
{
value 5.6;
}
active2
{
type fixedValue;
value.air 5.6;
}
These examples are provided in applications/test/dictionary.
The the default syntax can be changed from 'slash' to 'dot' in etc/controlDict
to revert to the previous behaviour:
OptimisationSwitches
{
.
.
.
// Default dictionary scoping syntax
inputSyntax slash; // Change to dot for previous behaviour
}
or within a specific dictionary by adding the entry
See applications/test/dictionary/testDotDict.
All models that require templating on the thermodynamic model, including
the thermodynamic models themselves, are now instantiated using a
centralised set of variadic macros. Seven macros exist to instantiate
models for different classes of thermodynamics model. These are:
forGases: All model combinations valid for gases
forCommonGases: The most commonly used gas models
forAbsoluteGases: A limited selection of gas models with absolute
forms of energy, for use with Xi-combustion models
forLiquids: All model combinations valid for liquids
forCommonLiquids: The most commonly used liquid models
forPolynomials: Model combinations with properties fitted to
polynomials
forSolids: All model combinations valid for solids
All the *ThermoPhysics typedefs have been removed, as this system was
fundamentally not extensible. The enormous lists of thermodynamic
instantiations that existed for reaction thermos, chemistry models,
tabulation methods, etc..., were extremely difficult to read and reason
about what combinations are valid under what circumstances. This change
centralises those decisions, makes them concise and readable, and makes
them consistent across the entire codebase.
Soot model selection has now been brought up to date in line with
chemistry, combustion, and others. The angle-bracketed part of the name
is no longer necessary; this information is determined directly from the
existing thermo model. So, now to select a mixture-fraction soot model,
the entry is simply:
sootModel mixtureFraction;
Rather than:
sootModel mixtureFraction<rhoReactionThermo,gasHThermoPhysics>;
The only place in which *ThermoPhysics typedefs are still required in
the selection name is in the thermalBaffle1D boundary condition. Here
there is no thermo model from which to determine a name. This eventually
needs resolving either by adding a selection mechanism similar to that
of the thermo packages themselves, or by removing this boundary
condition in favour of the (non-1D) thermal baffle boundary condition
and region model.
Following the generalisation of the TurbulenceModels library to support
non-Newtonian laminar flow including visco-elasticity and extensible to other
form of non-Newtonian behaviour the name TurbulenceModels is misleading and does
not properly represent how general the OpenFOAM solvers now are. The
TurbulenceModels now provides an interface to momentum transport modelling in
general and the plan is to rename it MomentumTransportModels and in preparation
for this the turbulenceProperties dictionary has been renamed momentumTransport
to properly reflect its new more general purpose.
The old turbulenceProperties name is supported for backward-compatibility.
renaming the legacy keywords
RASModel -> model
LESModel -> model
laminarModel -> model
which is simpler and clear within the context in which they are specified, e.g.
RAS
{
model kOmegaSST;
turbulence on;
printCoeffs on;
}
rather than
RAS
{
RASModel kOmegaSST;
turbulence on;
printCoeffs on;
}
The old keywords are supported for backward compatibility.
A surface geometry file should be stored in
$FOAM_TUTORIALS/resources/geometry if it is used in multiple cases,
otherwise it should be stored locally to the case. This change enforces
that across all tutorials.
Rather than defining patches for all external block faces to provide name and
type use the defaultPatch entry to collect undefined faces into a single named
and typed patch, e.g.
defaultPatch
{
name walls;
type wall;
}
The tutorial demonstrates generation of a C-grid mesh using blockMesh
The geometry is provided by a surface mesh (OBJ file) of the NACA0012 aerofoil
The case is setup with a freestream flow speed of Ma=0.72
Thanks to Kai Bastos at Duke University for the geometry and helpful input.
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.
Both stardard SIMPLE and the SIMPLEC (using the 'consistent' option in
fvSolution) are now supported for both subsonic and transonic flow of all
fluid types.
rhoSimpleFoam now instantiates the lower-level fluidThermo which instantiates
either a psiThermo or rhoThermo according to the 'type' specification in
thermophysicalProperties, e.g.
thermoType
{
type hePsiThermo;
mixture pureMixture;
transport sutherland;
thermo janaf;
equationOfState perfectGas;
specie specie;
energy sensibleInternalEnergy;
}
instantiates a psiThermo for a perfect gas with JANAF thermodynamics, whereas
thermoType
{
type heRhoThermo;
mixture pureMixture;
properties liquid;
energy sensibleInternalEnergy;
}
mixture
{
H2O;
}
instantiates a rhoThermo for water, see new tutorial
compressible/rhoSimpleFoam/squareBendLiq.
In order to support complex equations of state the pressure can no longer be
unlimited and rhoSimpleFoam now limits the pressure rather than the density to
handle start-up more robustly.
For backward compatibility 'rhoMin' and 'rhoMax' can still be used in the SIMPLE
sub-dictionary of fvSolution which are converted into 'pMax' and 'pMin' but it
is better to set either 'pMax' and 'pMin' directly or use the more convenient
'pMinFactor' and 'pMinFactor' from which 'pMax' and 'pMin' are calculated using
the fixed boundary pressure or reference pressure e.g.
SIMPLE
{
nNonOrthogonalCorrectors 0;
pMinFactor 0.1;
pMaxFactor 1.5;
transonic yes;
consistent yes;
residualControl
{
p 1e-3;
U 1e-4;
e 1e-3;
"(k|epsilon|omega)" 1e-3;
}
}
The fundamental properties provided by the specie class hierarchy were
mole-based, i.e. provide the properties per mole whereas the fundamental
properties provided by the liquidProperties and solidProperties classes are
mass-based, i.e. per unit mass. This inconsistency made it impossible to
instantiate the thermodynamics packages (rhoThermo, psiThermo) used by the FV
transport solvers on liquidProperties. In order to combine VoF with film and/or
Lagrangian models it is essential that the physical propertied of the three
representations of the liquid are consistent which means that it is necessary to
instantiate the thermodynamics packages on liquidProperties. This requires
either liquidProperties to be rewritten mole-based or the specie classes to be
rewritten mass-based. Given that most of OpenFOAM solvers operate
mass-based (solve for mass-fractions and provide mass-fractions to sub-models it
is more consistent and efficient if the low-level thermodynamics is also
mass-based.
This commit includes all of the changes necessary for all of the thermodynamics
in OpenFOAM to operate mass-based and supports the instantiation of
thermodynamics packages on liquidProperties.
Note that most users, developers and contributors to OpenFOAM will not notice
any difference in the operation of the code except that the confusing
nMoles 1;
entries in the thermophysicalProperties files are no longer needed or used and
have been removed in this commet. The only substantial change to the internals
is that species thermodynamics are now "mixed" with mass rather than mole
fractions. This is more convenient except for defining reaction equilibrium
thermodynamics for which the molar rather than mass composition is usually know.
The consequence of this can be seen in the adiabaticFlameT, equilibriumCO and
equilibriumFlameT utilities in which the species thermodynamics are
pre-multiplied by their molecular mass to effectively convert them to mole-basis
to simplify the definition of the reaction equilibrium thermodynamics, e.g. in
equilibriumCO
// Reactants (mole-based)
thermo FUEL(thermoData.subDict(fuelName)); FUEL *= FUEL.W();
// Oxidant (mole-based)
thermo O2(thermoData.subDict("O2")); O2 *= O2.W();
thermo N2(thermoData.subDict("N2")); N2 *= N2.W();
// Intermediates (mole-based)
thermo H2(thermoData.subDict("H2")); H2 *= H2.W();
// Products (mole-based)
thermo CO2(thermoData.subDict("CO2")); CO2 *= CO2.W();
thermo H2O(thermoData.subDict("H2O")); H2O *= H2O.W();
thermo CO(thermoData.subDict("CO")); CO *= CO.W();
// Product dissociation reactions
thermo CO2BreakUp
(
CO2 == CO + 0.5*O2
);
thermo H2OBreakUp
(
H2O == H2 + 0.5*O2
);
Please report any problems with this substantial but necessary rewrite of the
thermodynamic at https://bugs.openfoam.org
Henry G. Weller
CFD Direct Ltd.
Description
Constrain the field values within a specified region.
For example to set the turbulence properties within a porous region:
\verbatim
porosityTurbulence
{
type scalarFixedValueConstraint;
active yes;
scalarFixedValueConstraintCoeffs
{
selectionMode cellZone;
cellZone porosity;
fieldValues
{
k 30.7;
epsilon 1.5;
}
}
}
\endverbatim
See tutorials/compressible/rhoSimpleFoam/angledDuctExplicitFixedCoeff
constant/fvOptions for an example of this fvOption in action.
so that the specification of the name and dimensions are optional in property dictionaries.
Update tutorials so that the name of the dimensionedScalar property is
no longer duplicated but optional dimensions are still provided and are
checked on read.
by introducing rational base-classes rather than using the hideous
'switch' statement. Further rationalization of the cell-selection
mechanism will be implemented via an appropriate class hierarchy to
replace the remaining 'switch' statement.
Mesh-motion is currently handled very inefficiently for cellSets and not
at all for inter-region coupling. The former will be improved when the
cell-selection classes are written and the latter by making the
meshToMesh class a MeshObject after it has been corrected for mapFields.
fvOptions does not have the appropriate structure to support MRF as it
is based on option selection by user-specified fields whereas MRF MUST
be applied to all velocity fields in the particular solver. A
consequence of the particular design choices in fvOptions made it
difficult to support MRF for multiphase and it is easier to support
frame-related and field related options separately.
Currently the MRF functionality provided supports only rotations but
the structure will be generalized to support other frame motions
including linear acceleration, SRF rotation and 6DoF which will be
run-time selectable.
For multi-region cases the default location of blockMeshDict is now system/<region name>
If the blockMeshDict is not found in system then the constant directory
is also checked providing backward-compatibility
The old separate incompressible and compressible libraries have been removed.
Most of the commonly used RANS and LES models have been upgraded to the
new framework but there are a few missing which will be added over the
next few days, in particular the realizable k-epsilon model. Some of
the less common incompressible RANS models have been introduced into the
new library instantiated for incompressible flow only. If they prove to
be generally useful they can be templated for compressible and
multiphase application.
The Spalart-Allmaras DDES and IDDES models have been thoroughly
debugged, removing serious errors concerning the use of S rather than
Omega.
The compressible instances of the models have been augmented by a simple
backward-compatible eddyDiffusivity model for thermal transport based on
alphat and alphaEff. This will be replaced with a separate run-time
selectable thermal transport model framework in a few weeks.
For simplicity and ease of maintenance and further development the
turbulent transport and wall modeling is based on nut/nuEff rather than
mut/muEff for compressible models so that all forms of turbulence models
can use the same wall-functions and other BCs.
All turbulence model selection made in the constant/turbulenceProperties
dictionary with RAS and LES as sub-dictionaries rather than in separate
files which added huge complexity for multiphase.
All tutorials have been updated so study the changes and update your own
cases by comparison with similar cases provided.
Sorry for the inconvenience in the break in backward-compatibility but
this update to the turbulence modeling is an essential step in the
future of OpenFOAM to allow more models to be added and maintained for a
wider range of cases and physics. Over the next weeks and months more
turbulence models will be added of single and multiphase flow, more
additional sub-models and further development and testing of existing
models. I hope this brings benefits to all OpenFOAM users.
Henry G. Weller
