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.
Updated reacting solvers to use psiReactionThermophysicalTransportModel or
rhoReactionThermophysicalTransportModel as appropriate to provide support for
interacting heat and specie transport.
ThermophysicalTransportModel is now instantiated on both the
MomentmumTransportModel and also the particular thermo model model rather than
obtaining the fluidThermo from the MomentmumTransportModel. This gives direct
access to the higher-level thermo model used in the solver, for example
rhoReactionThermo so that complex ThermophysicalTransportModels requiring access
to the composition for example are instantiated only for thermo models that
provide it and also avoiding run-time up-casting of the thermo model.
Provides an abstraction of specie transport to support run-times selectable and
extensible multi-component thermal and specie laminar and turbulent transport.
providing the shear-stress term in the momentum equation for incompressible and
compressible Newtonian, non-Newtonian and visco-elastic laminar flow as well as
Reynolds averaged and large-eddy simulation of turbulent flow.
The general deviatoric shear-stress term provided by the MomentumTransportModels
library is named divDevTau for compressible flow and divDevSigma (sigma =
tau/rho) for incompressible flow, the spherical part of the shear-stress is
assumed to be either included in the pressure or handled separately. The
corresponding stress function sigma is also provided which in the case of
Reynolds stress closure returns the effective Reynolds stress (including the
laminar contribution) or for other Reynolds averaged or large-eddy turbulence
closures returns the modelled Reynolds stress or sub-grid stress respectively.
For visco-elastic flow the sigma function returns the effective total stress
including the visco-elastic and Newtonian contributions.
For thermal flow the heat-flux generated by thermal diffusion is now handled by
the separate ThermophysicalTransportModels library allowing independent run-time
selection of the heat-flux model.
During the development of the MomentumTransportModels library significant effort
has been put into rationalising the components and supporting libraries,
removing redundant code, updating names to provide a more logical, consistent
and extensible interface and aid further development and maintenance. All
solvers and tutorials have been updated correspondingly and backward
compatibility of the input dictionaries provided.
Henry G. Weller
CFD Direct Ltd.
This provides an extensible and run-time selectable framework to support complex
energy and specie transport models, in particular multi-component diffusion.
Currently only the Fourier for laminar and eddyDiffusivity for RAS and LES
turbulent flows are provided but the interface is general and the set of models
will be expanded in the near future.
The simplistic energy transport support in compressibleTurbulenceModels has been
abstracted and separated into the new ThermophysicalTransportModels library in
order to provide a more general interface to support complex energy and specie
transport models, in particular multi-component diffusion. Currently only the
Fourier for laminar and eddyDiffusivity for RAS and LES turbulent flows are
provided but the interface is general and the set of models will be expanded in
the near future.
The ThermalDiffusivity and EddyDiffusivity modelling layers remain in
compressibleTurbulenceModels but will be removed shortly and the alphat boundary
conditions will be moved to ThermophysicalTransportModels.
rhoPimpleFoam now produces identical results to rhoSimpleFoam when run
with a steady-state time-scheme. The intention is that this solver can
now be used as a reference when adding steady-state support to other
compressible solvers for which no SIMPLE variant exists.
rhoReactingFoam has also been updated to support SIMPLE operation, as it
shares a pressure equation with rhoPimpleFoam.
Changed the interpolation of HbyA from
fvc::flux(rho*HbyA)
to
fvc::interpolate(rho)*fvc::flux(HbyA)
for consistency with the latest compressible p-U algorithm in rhoPimpleFoam.
For most cases this change does not affect the results but test on highly
compressible, transonic and supersonic cases have shown a small but clear
benefit in the new form.
All multi-specie solvers function on the assumption that the
mass-diffusivities of the different species are the same. A consequence
of this is that the diffusivities of energy and mass must be the same,
otherwise mass diffusivity results in unphysical temperature
fluctuations. This change enforces this requirement across all
multi-species solvers.
For the same reason, the turbulent Schmidt number has been removed from
the multi-component phase model in reactingEulerFoam. In order to obey
physical constraints this Schmidt number had to be exactly the same as
the Prandtl number. This condition is now enforced by the solver, rather
than relying on the input being correct.
solidChemistryModel is not implemented in a general way but specialised to form
the basis of the highly specific pyrolysis mode. The handling of reactions is
hard-coded for forward reactions only, the Jacobian was present but incomplete
so any ODE solvers requiring the Jacobian would either fail, diverge or produce
incorrect results. It is not clear if many or any parts of the
solidChemistryModel are correct, in particular there is no handling for the
solid surface area per unit volume. After a lot of refactoring work it has
become clear that solidChemistryModel needs a complete rewrite and can benefit
from all the recent development work done on the now more general
StandardChemistryModel.
This allows much greater flexibility in the instantiation of reaction system
which may in general depend on fields other than the thermodynamic state. This
also simplifies mixture thermodynamics removing the need for the reactingMixture
and the instantiation of all the thermodynamic package combinations depending on
it.
Currently these deleted function declarations are still in the private section
of the class declarations but will be moved by hand to the public section over
time as this is too complex to automate reliably.
Replaced all uses of complex Xfer class with C++11 "move" constructors and
assignment operators. Removed the now redundant Xfer class.
This substantial changes improves consistency between OpenFOAM and the C++11 STL
containers and algorithms, reduces memory allocation and copy overhead when
returning containers from functions and simplifies maintenance of the core
libraries significantly.
The sub-loops of the solution control are now named more consistently,
with ambiguously named methods such as finalIter replaced with ones
like finalPimpleIter, so that it is clear which loop they represent.
In addition, the final logic has been improved so that it restores state
after a sub-iteration, and so that sub-iterations can be used on their
own without an outer iteration in effect. Previously, if the
non-orthogonal loop were used outside of a pimple/piso iteration, the
final iteration would not execute with final settings.
The radiation modelling library has been moved out of
thermophysicalProperties into the top-level source directory. Radiation
is a process, not a property, and belongs alongside turbulence,
combustion, etc...
The namespaces used within the radiation library have been made
consistent with the rest of the code. Selectable sub-models are in
namespaces named after their base classes. Some models have been
renamed remove the base type from the suffix, as this is unnecessary.
These renames are:
Old name: New name:
binaryAbsorptionEmission binary
cloudAbsorptionEmission cloud
constantAbsorptionEmission constant
greyMeanAbsorptionEmission greyMean/greyMeanCombustion
greyMeanSolidAbsorptionEmission greyMeanSolid
wideBandAbsorptionEmission wideBand/wideBandCombustion
cloudScatter cloud
constantScatter constant
mixtureFractionSoot mixtureFraction
Some absorption-emission models have been split into versions which do
and don't use the heat release rate. The version that does has been
given the post-fix "Combustion" and has been moved into the
combustionModels library. This removes the dependence on a registered
Qdot field, and makes the models compatible with the recent removal of
that field from the combustion solvers.
The Qdot field has been removed from all reacting solvers, in favour of
computing on the fly whenever it is needed. It can still be generated
for post-processing purposes by means of the Qdot function object. This
change reduces code duplication and storage for all modified solvers.
The Qdot function object has been applied to a number of tutorials in
order to retain the existing output.
A fix to Qdot has also been applied for multi-phase cases.
Registration occurs when the temporary field is transferred to a non-temporary
field via a constructor or if explicitly transferred to the database via the
regIOobject "store" methods.
The selection of the "Final" solver settings is now handled automatically within
the "<equation>.solve()" call and there is no longer any need no provide a bool
argument for specific cases. This simplifies the solution algorithm loop
structures and ensures consistency in behaviour across all solvers.
All tutorials have been updated to correspond to the now consistent rules.
Now for transient simulations "Final" solver settings are required for ALL
equations providing consistency between the solution of velocity, energy,
composition and radiation properties.
However "Final" relaxation factors are no longer required for fields or
equations and if not present the standard value for the variable will be
applied. Given that relaxation factors other than 1 are rarely required for
transient runs and hence the same for all iterations including the final one
this approach provide simpler input while still providing the flexibility to
specify a different value for the final iteration if required. For steady cases
it is usual to execute just 1 outer iteration per time-step for which the
standard relaxation factors are appropriate, and if more than one iteration is
executed it is common to use the same factors for both. In the unlikely event
of requiring different relaxation factors for the final iteration this is still
possible to specify via the now optional "Final" specification.
