The standard Jayatilleke thermal wall function now permits evaluation
via static functions. The boiling wall function now uses these
functions, thereby removing the phase-Jayatilleke base class and
associated duplication of the Jayatilleke model.
It is now possible to map from one field to another within the same
patch, using the mappedValue boundary condition. The restriction is that
the mapping must be from a different field, otherwise field values are
being assigned to themselves, which produces an undefined result.
The mappedValue boundary condition can now be used in place of the
copiedFixedValue condition in the multiphaseEuler module. The
copiedFixedValue condition has therefore been removed.
In addition, the error messages that result from casting a patch to its
mapping engine (mappedPatchBase) have been standardised, and made more
specific to the situation in which the mapping is applied. It may be
inappropriate, for example, to map within the same region or patch.
These cases are now identified and appropriate error messages are
generated.
The error messages have also been made IO errors, so they now provide
context with regards to the dictionary entries that they relate to.
executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations. Replaces solidDisplacementFoam and
solidEquilibriumDisplacementFoam and all the corresponding tutorials have been
updated and moved to tutorials/modules/solidDisplacement.
Class
Foam::solvers::solidDisplacement
Description
Solver module for steady or transient segregated finite-volume solution of
linear-elastic, small-strain deformation of a solid body, with optional
thermal diffusion and thermal stresses.
Solves for the displacement vector field D, also generating the stress
tensor field sigma, including the thermal stress contribution if selected.
SourceFiles
solidDisplacement.C
The accelerationFactor option in solidEquilibriumDisplacementFoam is now
available in solidDisplacementFoam when running steady-state, providing a >5x
speed-up to convergence of the updated beamEndLoad case. This makes
solidEquilibriumDisplacementFoam redundant and it has been removed.
so that the same BC can be used for both solidDisplacementFoam and
solidEquilibriumDisplacementFoam. Also updated the beamEndLoad tutorial and
added a solidDisplacementFoam version to test the combined BC.
executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations. Replaces XiFoam and all the corresponding
tutorials have been updated and moved to tutorials/modules/XiFluid.
Class
Foam::solvers::XiFluid
Description
Solver module for compressible premixed/partially-premixed combustion with
turbulence modelling.
Combusting RANS code using the b-Xi two-equation model.
Xi may be obtained by either the solution of the Xi transport
equation or from an algebraic expression. Both approaches are
based on Gulder's flame speed correlation which has been shown
to be appropriate by comparison with the results from the
spectral model.
Strain effects are encorporated directly into the Xi equation
but not in the algebraic approximation. Further work need to be
done on this issue, particularly regarding the enhanced removal rate
caused by flame compression. Analysis using results of the spectral
model will be required.
For cases involving very lean Propane flames or other flames which are
very strain-sensitive, a transport equation for the laminar flame
speed is present. This equation is derived using heuristic arguments
involving the strain time scale and the strain-rate at extinction.
the transport velocity is the same as that for the Xi equation.
Uses the flexible PIMPLE (PISO-SIMPLE) solution for time-resolved and
pseudo-transient and steady simulations.
Optional fvModels and fvConstraints are provided to enhance the simulation
in many ways including adding various sources, chemical reactions,
combustion, Lagrangian particles, radiation, surface film etc. and
constraining or limiting the solution.
Reference:
\verbatim
Greenshields, C. J., & Weller, H. G. (2022).
Notes on Computational Fluid Dynamics: General Principles.
CFD Direct Ltd.: Reading, UK.
\endverbatim
SourceFiles
XiFluid.C
See also
Foam::solvers::fluidSolver
Foam::solvers::isothermalFluid
executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations. Replaces interFoam and all the corresponding
tutorials have been updated and moved to tutorials/modules/incompressibleVoF.
Both incompressibleVoF and compressibleVoF solver modules are derived from the
common two-phase VoF base-class solvers::VoFSolver which handles the
complexities of VoF interface-compression, boundedness and conservation with
2nd-order schemes in space and time using the semi-implicit MULES limiter and
solution proceedure. This maximises code re-use, improves readability and
simplifies maintenance.
Class
Foam::solvers::incompressibleVoF
Description
Solver module for for 2 incompressible, isothermal immiscible fluids using a
VOF (volume of fluid) phase-fraction based interface capturing approach,
with optional mesh motion and mesh topology changes including adaptive
re-meshing.
The momentum and other fluid properties are of the "mixture" and a single
momentum equation is solved.
Either mixture or two-phase transport modelling may be selected. In the
mixture approach a single laminar, RAS or LES model is selected to model the
momentum stress. In the Euler-Euler two-phase approach separate laminar,
RAS or LES selected models are selected for each of the phases.
Uses the flexible PIMPLE (PISO-SIMPLE) solution for time-resolved and
pseudo-transient and steady simulations.
Optional fvModels and fvConstraints are provided to enhance the simulation
in many ways including adding various sources, Lagrangian
particles, surface film etc. and constraining or limiting the solution.
SourceFiles
incompressibleVoF.C
See also
Foam::solvers::VoFSolver
Foam::solvers::compressibleVoF
In order to ensure temperature consistency between the phases it is necessary to
solve for the mixture temperature rather than the mixture energy or phase
energies which makes it very difficult to conserve energy. The new temperature
equation is a temperature correction on the combined phase energy equations
which will conserve the phase and mixture energies at convergence. The
heat-flux (Laplacian) term is maintained in mixture temperature form so
heat-transfer boundary conditions, in particular for CHT, remain in terms of the
mixture kappaEff. The fvModels are applied to the phase energy equations and
the implicit part converted into an implicit term in the temperature correction
part of the equation to improve convergence and stability.
This development has required some change to the alphaEqn.H and interFoam has
been updated for consistency in preparation for conversion into the
solvers::incompressibleVoF modular module.
All compressibleVoF fvModels and tutorial cases have been updated for the above
change. Note that two entries are now required for the convection terms in the
temperature equation, one for explicit phase energy terms and another for the
implicit phase temperature correction terms, e.g.
tutorials/modules/compressibleVoF/ballValve
div(alphaRhoPhi,e) Gauss limitedLinear 1;
div(alphaRhoPhi,T) Gauss upwind;
In the above the upwind scheme is selected for the phase temperature correction
terms as they are corrections and will converge to a zero contribution. However
there may be cases which converge better if the same scheme is used for both the
energy and temperature terms, more testing is required.
The new optional PIMPLE control transportPredictionFirst is used to select if
the transport modelling predictor is executed ever PIMPLE iteration or only on
the first, which is the default.
Also the transportCorr() function has been renamed correctTransport() for
consistency and the tutorials updated to use the new control name
transportCorrectionFinal instead of the previous name turbOnFinalIterOnly;
support for turbOnFinalIterOnly is maintained for backwards-compatibility.
With the addition of the compressibleInterPhaseThermophysicalTransportModel
thermophysicalTransportModel the compressibleVoF modular solver now support
conjugate heat transfer (CHT).
Th new tutorials/modules/CHT/VoFcoolingCylinder2D tutorial case is provided to
demonstrate this functionality and shows a heated ceramic rod with air flowing
over the top and water underneath.
This function object writes graphs of patch face values, area-averaged in
planes perpendicular to a given direction. It adaptively grades the
distribution of graph points to match the resolution of the mesh.
Example of function object specification:
patchCutLayerAverage1
{
type patchCutLayerAverage;
libs ("libpatchCutLayerAverageFunctionObject.so");
writeControl writeTime;
writeInterval 1;
patch lowerWall;
direction (1 0 0);
nPoints 100;
interpolate no;
fields (p U);
axis x;
setFormat raw;
}
A packaged function object is also included, which permits the following
syntax to be used, either with #includeFunc in the system/controlDict,
or with the -func option to foamPostProcess:
graphPatchCutLayerAverage
(
funcName=aerofoilLowerPressure,
patch=aerofoilLower,
direction=(0.15 -0.016 0),
nPoints=100,
p
)
angleUnits is a more logical name for the user-input as it specifies the units
of the angles written rather than the format of the numbers. The previous name
angleFormat is supported for backwards-compatibility
Class
Foam::functionObjects::rigidBodyState
Description
Writes the rigid body motion state.
Usage
\table
Property | Description | Required | Default value
type | type name: rigidBodyState | yes |
angleUnits | degrees or radians | no | radians
\endtable
Example of function object specification:
\verbatim
rigidBodyState
{
type rigidBodyState;
libs ("librigidBodyState.so");
angleUnits degrees;
}
\endverbatim
Class
Foam::functionObjects::sixDoFRigidBodyState
Description
Writes the 6-DoF motion state.
Example of function object specification:
\verbatim
sixDoFRigidBodyState
{
type sixDoFRigidBodyState;
libs ("libsixDoFRigidBodyState.so");
angleUnits degrees;
}
\endverbatim
Usage
\table
Property | Description | Required | Default value
type | type name: sixDoFRigidBodyState | yes |
angleUnits | degrees or radians | no | radian
\endtable
The timeName() function simply returns the dimensionedScalar::name() which holds
the user-time name of the current time and now that timeName() is no longer
virtual the dimensionedScalar::name() can be called directly. The timeName()
function implementation is maintained for backward-compatibility.
The localInteraction model now no longer requires specification of an
interaction on any constrained patch type (e.g., symmetry, cyclic, ...).
Non-constrained types (patch, wall, ...) require an interaction to be
specified as before and will trigger an error if this is not the case.
In addition, constrained patches can be overridden by providing a
'patchType' specifier, in the same way as would be done to override a
constrained boundary condition for finite volume.
The filter tutorial now correctly demonstrates something unique; i.e.,
particles rebounding from a cyclic. It has therefore been reinstated.
Resolves (properly) bug report https://bugs.openfoam.org/view.php?id=3923
A set of routines for cutting polyhedra have been added. These can cut
polyhedral cells based on the adjacent point values and an iso-value
which defines the surface. The method operates directly on the
polyhedral cells; it does not decompose them into tetrahedra at any
point. The routines can compute the cut topology as well as integrals of
properties above and below the cut surface.
An iso-surface algorithm has been added based on these polyhedral
cutting routines. It is significantly more robust than the previous
algorithm, and produces compact surfaces equivalent to the previous
algorithm's maximum filtering level. It is also approximately 3 times
faster than the previous algorithm, and 10 times faster when run
repeatedly on the same set of cells (this is because some addressing is
cached and reused).
This algorithm is used by the 'isoSurface', 'distanceSurface' and
'cutPlane' sampled surfaces.
The 'cutPlane' sampled surface is a renaming of 'cuttingPlane' to make
it consistent with the corresponding packaged function. The name
'cuttingPlane' has been retained for backwards compatibility and can
still be used to select a 'cutPlane' surface. The legacy 'plane' surface
has been removed.
The 'average' keyword has been removed from specification of these
sampled surfaces as cell-centred values are no longer used in the
generation of or interpolation to an iso-surface. The 'filtering'
keyword has also been removed as it relates to options within the
previous algorithm. Zone support has been reinstated into the
'isoSurface' sampled surface. Interpolation to all these sampled
surfaces has been corrected to exactly match the user-selected
interpolation scheme, and the interpolation procedure no longer
unnecessarily re-generates data that is already available.
which can be selected and executed in foamMultiRun for complex CHT cases. This
is a much more general, flexible, extensible and maintainable structure than the
now deprecated regionModels system and associated clutter.
This serves as an example of cavitation modelling with the
multiphaseEuler module. This case also contains validation of the
pressure profile along the hydrofoil against experimental data.
Based on a case contributed by Petteri Peltonen, VTT.
The cavitation models used by the interFoam solver and the
compressibleVoF solver module can now be applied regardless of the
ordering of the liquid and vapour phases. A "liquid" keyword is now
required in the model specification in order to control which phase is
considered to be the condensed liquid state. Previously the liquid phase
was assumed to be the first of the two phases.
The multiphaseEuler module now uses saturation models from the
centralised thermophysical properties library.
The control of these models is slightly different than for the previous
multiphaseEuler-specific saturation models. Where previously a
"saturationPressure" or "saturationTemperature" sub-dictionary was
employed, now "pSat" and "Tsat" entries are used which can be specified
flexibly in a similar manner to function1-s. See the previous commit for
details.
Supersedes and replaces the tutorials/modules/multiphaseEuler/wallBoiling case
as it is more physical and representative of a real case.
Patch contributed by Juho Peltola, VTT.
Class
Foam::coupledMultiphaseTemperatureFvPatchScalarField
Description
Mixed boundary condition for the phase temperature of a phase in an
Euler-Euler multiphase simulation, to be used for heat-transfer with another
region in a CHT case. Optional thin wall material layer resistances can be
specified through thicknessLayers and kappaLayers entries.
See also
Foam::coupledTemperatureFvPatchScalarField
The new tutorial case tutorials/modules/CHT/multiphaseCoolingCylinder2D is a
variant of the coolingCylinder2D case in which a 10% oil droplets in water
mixture flows over and cools a hot cylinder. The case in run with the
foamMultiRun multi-solver executor.
Simulating the mixing of two miscible liquids is possible my considering
them as different species of a multicomponent fluid. This approach also
supports an arbitrary number of liquids. The twoLiquidMixingFoam solver
has therefore been removed and its tutorials converted to use the
multicomponentFluid solver module.
Bubble waiting time ratio has been made a user adjustable parameter, and
the names of the fields reported by the wallBoilingProperties function
have been rationalised.
This tutorial's purpose was to demonstrate rebound off an internal
cyclic patch, and thereby "filter" the particles out of the downstream
sections of the geometry. The case does not correctly do this. The patch
interaction handling is incomplete and does not support overriding
cyclic boundary conditions in this way. This tutorial has therefore been
removed pending funding to improve the patch interaction modelling.
Resolves bug report https://bugs.openfoam.org/view.php?id=3923
Now cases with mesh refinement/unrefinement can be run with the 2nd-order
backward time scheme. However this is for static meshes only, 2nd-order in time
with topology change AND mesh-motion is not currently supported.
These tutorials now make make use of the phaseTurbulenceStabilisation
fvModel and the wallBoilingProperties functionObject.
Patch contributed by Juho Peltola, VTT.
executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations. Replaces multiphaseEulerFoam and all the
corresponding tutorials have been updated and moved to
tutorials/modules/multiphaseEuler.
Class
Foam::solvers::multiphaseEuler
Description
Solver module for a system of any number of compressible fluid phases with a
common pressure, but otherwise separate properties. The type of phase model
is run time selectable and can optionally represent multiple species and
in-phase reactions. The phase system is also run time selectable and can
optionally represent different types of momentum, heat and mass transfer.
Uses the flexible PIMPLE (PISO-SIMPLE) solution for time-resolved and
pseudo-transient and steady simulations.
Optional fvModels and fvConstraints are provided to enhance the simulation
in many ways including adding various sources, Lagrangian
particles, surface film etc. and constraining or limiting the solution.
SourceFiles
multiphaseEuler.C
See also
Foam::solvers::compressibleVoF
Foam::solvers::fluidSolver
Foam::solvers::incompressibleFluid
No advantage was found in the specific snappyHexMesh settings previously
specified for this case. This case now uses settings from the standard
snappyHexMesh.cfg file.
The rotating region has also been modified to align better with the
original block mesh. For sliding interface problems this is important in
order to reliably get good conformance to the cylinder edges.
After direct and regular expression matching the scheme name is now filtered to
remove and group/phase extensions in the name and matched again with the schemes
dictionary.
This significantly simplifies the specification of schemes in multiphase
simulations, instead of the rather messy regular expressions the new method
allows schemes to be specified without the group/phase name extension and the
scheme is then used for all groups/phases. For example in the bubbleColumn
tutorials the schemes can now be specified thus:
divSchemes
{
default none;
div(phi,alpha) Gauss vanLeer;
div(phir,alpha,alpha) Gauss vanLeer;
div(alphaRhoPhi,U) Gauss limitedLinearV 1;
div(phi,U) Gauss limitedLinearV 1;
div(alphaRhoPhi,e) Gauss limitedLinear 1;
div(alphaRhoPhi,K) Gauss limitedLinear 1;
div(alphaRhoPhi,(p|rho)) Gauss limitedLinear 1;
div((((alpha*rho)*nuEff)*dev2(T(grad(U))))) Gauss linear;
}
rather than using complex regular expressions as done previously:
divSchemes
{
default none;
div(phi,alpha.air) Gauss vanLeer;
div(phi,alpha.water) Gauss vanLeer;
div(phir,alpha.water,alpha.air) Gauss vanLeer;
div(phir,alpha.air,alpha.water) Gauss vanLeer;
"div\(alphaRhoPhi.*,U.*\)" Gauss limitedLinearV 1;
"div\(phi.*,U.*\)" Gauss limitedLinearV 1;
"div\(alphaRhoPhi.*,(h|e).*\)" Gauss limitedLinear 1;
"div\(alphaRhoPhi.*,K.*\)" Gauss limitedLinear 1;
"div\(alphaRhoPhi.*,\(p\|rho.*\)\)" Gauss limitedLinear 1;
"div\(alphaRhoPhi.*,\(p\|rho.*\)\)" Gauss limitedLinear 1;
"div\(\(\(\(alpha.*\*rho.*\)*nuEff.*\)\*dev2\(T\(grad\(U.*\)\)\)\)\)" Gauss linear;
}
The thermodynamic density field is now named "rho" by default and only renamed
"thermo:rho" by solvers that create and maintain a separate continuity density
field which is named "rho". This change significantly simplifies and
standardises the specification of schemes and boundary conditions requiring
density as it is now always named "rho" or "rho.<phase>" unless under some very
unusual circumstances the thermodynamic rather than continuity density is
required for a solver maintaining both.
The advantage of this change is particularly noticeable for multiphase
simulations in which each phase has its own density now named "rho.<phase>"
rather than "thermo:rho.<phase>" as separate phase continuity density fields are
not required so for multiphaseEulerFoam the scheme specification:
"div\(alphaRhoPhi.*,\(p\|thermo:rho.*\)\)" Gauss limitedLinear 1;
is now written:
"div\(alphaRhoPhi.*,\(p\|rho.*\)\)" Gauss limitedLinear 1;
The basic thermophysical properties are now considered fundamental and complex
models like kineticTheoryModel using these names for some other purpose must
disambiguate using typedName to prepend the model name to the field name.
This change standardises, rationalises and simplifies the specification of
fvSchemes and boundary conditions.
thermo:rho will also be renamed rho in a subsequent commit to complete this
rationalisation.
