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.
The standard naming convention for heat flux is "q" and this is used for the
conductive and convective heat fluxes is OpenFOAM. The use of "Qr" for
radiative heat flux is an anomaly which causes confusion, particularly for
boundary conditions in which "Q" is used to denote power in Watts. The name of
the radiative heat flux has now been corrected to "qr" and all models, boundary
conditions and tutorials updated.
including support for TDAC and ISAT for efficient chemistry calculation.
Description
Eddy Dissipation Concept (EDC) turbulent combustion model.
This model considers that the reaction occurs in the regions of the flow
where the dissipation of turbulence kinetic energy takes place (fine
structures). The mass fraction of the fine structures and the mean residence
time are provided by an energy cascade model.
There are many versions and developments of the EDC model, 4 of which are
currently supported in this implementation: v1981, v1996, v2005 and
v2016. The model variant is selected using the optional \c version entry in
the \c EDCCoeffs dictionary, \eg
\verbatim
EDCCoeffs
{
version v2016;
}
\endverbatim
The default version is \c v2015 if the \c version entry is not specified.
Model versions and references:
\verbatim
Version v2005:
Cgamma = 2.1377
Ctau = 0.4083
kappa = gammaL^exp1 / (1 - gammaL^exp2),
where exp1 = 2, and exp2 = 2.
Magnussen, B. F. (2005, June).
The Eddy Dissipation Concept -
A Bridge Between Science and Technology.
In ECCOMAS thematic conference on computational combustion
(pp. 21-24).
Version v1981:
Changes coefficients exp1 = 3 and exp2 = 3
Magnussen, B. (1981, January).
On the structure of turbulence and a generalized
eddy dissipation concept for chemical reaction in turbulent flow.
In 19th Aerospace Sciences Meeting (p. 42).
Version v1996:
Changes coefficients exp1 = 2 and exp2 = 3
Gran, I. R., & Magnussen, B. F. (1996).
A numerical study of a bluff-body stabilized diffusion flame.
Part 2. Influence of combustion modeling and finite-rate chemistry.
Combustion Science and Technology, 119(1-6), 191-217.
Version v2016:
Use local constants computed from the turbulent Da and Re numbers.
Parente, A., Malik, M. R., Contino, F., Cuoci, A., & Dally, B. B.
(2016).
Extension of the Eddy Dissipation Concept for
turbulence/chemistry interactions to MILD combustion.
Fuel, 163, 98-111.
\endverbatim
Tutorials cases provided: reactingFoam/RAS/DLR_A_LTS, reactingFoam/RAS/SandiaD_LTS.
This codes was developed and contributed by
Zhiyi Li
Alessandro Parente
Francesco Contino
from BURN Research Group
and updated and tested for release by
Henry G. Weller
CFD Direct Ltd.
The defaultCoeffs entry is now redundant and supported only for backward
compatibility. To specify a liquid with default coefficients simply leave the
coefficients dictionary empty:
liquids
{
H2O {}
}
Any or all of the coefficients may be overridden by specifying the properties in
the coefficients dictionary, e.g.
liquids
{
H2O
{
rho
{
a 1000;
b 0;
c 0;
d 0;
}
}
}
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.
boundaryRadiationProperties: updating to new format
dynamicMeshDict and snappyHexMeshDict in utorials/multiphase/interDyMFoam/RAS/motorBike to follow Mattijs Git lab id 381
New reactingFoam tutorial counterFlowFlame2DLTS_GRI_TDAC demonstrates this new
functionality.
Additionally the ISAT table growth algorithm has been further optimized
providing an overall speedup of between 15% and 38% for the tests run so far.
Updates to TDAC and ISAT provided by Francesco Contino.
Implementation updated and integrated into OpenFOAM-dev by
Henry G. Weller, CFD Direct Ltd with the help of Francesco Contino.
Original code providing all algorithms for chemistry reduction and
tabulation contributed by Francesco Contino, Tommaso Lucchini, Gianluca
D’Errico, Hervé Jeanmart, Nicolas Bourgeois and Stéphane Backaert.
