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.
Provides run-time selection of buoyancy sources for compressible solvers
Replaces the built-in buoyancy sources in XiFoam, reactingFoam and
rhoReactingFoam.
e.g. in constant/fvOptions specify
momentumSource
{
type buoyancyForce;
buoyancyForceCoeffs
{
fieldNames (U);
}
}
and optionally specify the buoyancy energy source in the enthalpy
equation:
energySource
{
type buoyancyEnergy;
buoyancyEnergyCoeffs
{
fieldNames (h);
}
}
or internal energy equation
energySource
{
type buoyancyEnergy;
buoyancyEnergyCoeffs
{
fieldNames (e);
}
}
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.
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
At the specie level:
hs = sensible enthalpy
ha = absolute (what was total) enthalpy
es = sensibly internal energy
ea = absolute (what was total) internal energy
At top-level
Rename total enthalpy h -> ha
Rename sensible enthalpy hs -> h
Combined h, hs, e and es thermo packages into a single structure.
Thermo packages now provide "he" function which may return either enthalpy or
internal energy, sensible or absolute according to the run-time selected form
alphaEff now returns the effective diffusivity for the particular energy which
the thermodynamics package is selected to solve for.
