in which different solver modules can be selected in each region to for complex
conjugate heat-transfer and other combined physics problems such as FSI
(fluid-structure interaction).
For single-region simulations the solver module is selected, instantiated and
executed in the PIMPLE loop in the new foamRun application.
For multi-region simulations the set of solver modules, one for each region, are
selected, instantiated and executed in the multi-region PIMPLE loop of new the
foamMultiRun application.
This provides a very general, flexible and extensible framework for complex
coupled problems by creating more solver modules, either by converting existing
solver applications or creating new ones.
The current set of solver modules provided are:
isothermalFluid
Solver module for steady or transient turbulent flow of compressible
isothermal fluids with optional mesh motion and mesh topology changes.
Created from the rhoSimpleFoam, rhoPimpleFoam and buoyantFoam solvers but
without the energy equation, hence isothermal. The buoyant pressure
formulation corresponding to the buoyantFoam solver is selected
automatically by the presence of the p_rgh pressure field in the start-time
directory.
fluid
Solver module for steady or transient turbulent flow of compressible fluids
with heat-transfer for HVAC and similar applications, with optional
mesh motion and mesh topology changes.
Derived from the isothermalFluid solver module with the addition of the
energy equation from the rhoSimpleFoam, rhoPimpleFoam and buoyantFoam
solvers, thus providing the equivalent functionality of these three solvers.
multicomponentFluid
Solver module for steady or transient turbulent flow of compressible
reacting fluids with optional mesh motion and mesh topology changes.
Derived from the isothermalFluid solver module with the addition of
multicomponent thermophysical properties energy and specie mass-fraction
equations from the reactingFoam solver, thus providing the equivalent
functionality in reactingFoam and buoyantReactingFoam. Chemical reactions
and/or combustion modelling may be optionally selected to simulate reacting
systems including fires, explosions etc.
solid
Solver module for turbulent flow of compressible fluids for conjugate heat
transfer, HVAC and similar applications, with optional mesh motion and mesh
topology changes.
The solid solver module may be selected in solid regions of a CHT case, with
either the fluid or multicomponentFluid solver module in the fluid regions
and executed with foamMultiRun to provide functionality equivalent
chtMultiRegionFoam but in a flexible and extensible framework for future
extension to more complex coupled problems.
All the usual fvModels, fvConstraints, functionObjects etc. are available with
these solver modules to support simulations including body-forces, local sources,
Lagrangian clouds, liquid films etc. etc.
Converting compressibleInterFoam and multiphaseEulerFoam into solver modules
would provide a significant enhancement to the CHT capability and incompressible
solvers like pimpleFoam run in conjunction with solidDisplacementFoam in
foamMultiRun would be useful for a range of FSI problems. Many other
combinations of existing solvers converted into solver modules could prove
useful for a very wide range of complex combined physics simulations.
All tutorials from the rhoSimpleFoam, rhoPimpleFoam, buoyantFoam, reactingFoam,
buoyantReactingFoam and chtMultiRegionFoam solver applications replaced by
solver modules have been updated and moved into the tutorials/modules directory:
modules
├── CHT
│ ├── coolingCylinder2D
│ ├── coolingSphere
│ ├── heatedDuct
│ ├── heatExchanger
│ ├── reverseBurner
│ └── shellAndTubeHeatExchanger
├── fluid
│ ├── aerofoilNACA0012
│ ├── aerofoilNACA0012Steady
│ ├── angledDuct
│ ├── angledDuctExplicitFixedCoeff
│ ├── angledDuctLTS
│ ├── annularThermalMixer
│ ├── BernardCells
│ ├── blockedChannel
│ ├── buoyantCavity
│ ├── cavity
│ ├── circuitBoardCooling
│ ├── decompressionTank
│ ├── externalCoupledCavity
│ ├── forwardStep
│ ├── helmholtzResonance
│ ├── hotRadiationRoom
│ ├── hotRadiationRoomFvDOM
│ ├── hotRoom
│ ├── hotRoomBoussinesq
│ ├── hotRoomBoussinesqSteady
│ ├── hotRoomComfort
│ ├── iglooWithFridges
│ ├── mixerVessel2DMRF
│ ├── nacaAirfoil
│ ├── pitzDaily
│ ├── prism
│ ├── shockTube
│ ├── squareBend
│ ├── squareBendLiq
│ └── squareBendLiqSteady
└── multicomponentFluid
├── aachenBomb
├── counterFlowFlame2D
├── counterFlowFlame2D_GRI
├── counterFlowFlame2D_GRI_TDAC
├── counterFlowFlame2DLTS
├── counterFlowFlame2DLTS_GRI_TDAC
├── cylinder
├── DLR_A_LTS
├── filter
├── hotBoxes
├── membrane
├── parcelInBox
├── rivuletPanel
├── SandiaD_LTS
├── simplifiedSiwek
├── smallPoolFire2D
├── smallPoolFire3D
├── splashPanel
├── verticalChannel
├── verticalChannelLTS
└── verticalChannelSteady
Also redirection scripts are provided for the replaced solvers which call
foamRun -solver <solver module name> or foamMultiRun in the case of
chtMultiRegionFoam for backward-compatibility.
Documentation for foamRun and foamMultiRun:
Application
foamRun
Description
Loads and executes an OpenFOAM solver module either specified by the
optional \c solver entry in the \c controlDict or as a command-line
argument.
Uses the flexible PIMPLE (PISO-SIMPLE) solution for time-resolved and
pseudo-transient and steady simulations.
Usage
\b foamRun [OPTION]
- \par -solver <name>
Solver name
- \par -libs '(\"lib1.so\" ... \"libN.so\")'
Specify the additional libraries loaded
Example usage:
- To run a \c rhoPimpleFoam case by specifying the solver on the
command line:
\verbatim
foamRun -solver fluid
\endverbatim
- To update and run a \c rhoPimpleFoam case add the following entries to
the controlDict:
\verbatim
application foamRun;
solver fluid;
\endverbatim
then execute \c foamRun
Application
foamMultiRun
Description
Loads and executes an OpenFOAM solver modules for each region of a
multiregion simulation e.g. for conjugate heat transfer.
The region solvers are specified in the \c regionSolvers dictionary entry in
\c controlDict, containing a list of pairs of region and solver names,
e.g. for a two region case with one fluid region named
liquid and one solid region named tubeWall:
\verbatim
regionSolvers
{
liquid fluid;
tubeWall solid;
}
\endverbatim
The \c regionSolvers entry is a dictionary to support name substitutions to
simplify the specification of a single solver type for a set of
regions, e.g.
\verbatim
fluidSolver fluid;
solidSolver solid;
regionSolvers
{
tube1 $fluidSolver;
tubeWall1 solid;
tube2 $fluidSolver;
tubeWall2 solid;
tube3 $fluidSolver;
tubeWall3 solid;
}
\endverbatim
Uses the flexible PIMPLE (PISO-SIMPLE) solution for time-resolved and
pseudo-transient and steady simulations.
Usage
\b foamMultiRun [OPTION]
- \par -libs '(\"lib1.so\" ... \"libN.so\")'
Specify the additional libraries loaded
Example usage:
- To update and run a \c chtMultiRegion case add the following entries to
the controlDict:
\verbatim
application foamMultiRun;
regionSolvers
{
fluid fluid;
solid solid;
}
\endverbatim
then execute \c foamMultiRun
Full backward-compatibility is provided which support for both multiComponentMixture and
multiComponentPhaseModel provided but all tutorials have been updated.
The cellProc field is the field of cell-processor labels.
The names "distribution" and "dist" have been removed as these are
ambiguous in relation to other forms of distribution and to distance.
The reconstructPar utility now reconstructs the mesh if and when it is
necessary to do so. The reconstructParMesh utility is therefore no
longer necessary and has been removed.
It was necessary/advantagous to consolidate these utilities into one
because in the case of mesh changes it becomes increasingly less clear
which of the separate utilities is responsible for reconstructing data
that is neither clearly physical field nor mesh topology; e.g., moving
points, sets, refinement data, and so on.
This utility now always creates two patches, and only creates duplicate
faces when they connect to different cells and point in opposite
directions. Now that ACMI has been removed, there is no need to create
duplicate faces on the same cell and with similar orientations. This is
unituitive and is now considered an invalid mesh topology.
The preferred syntax for createBaffles is now as follows:
internalFacesOnly true;
baffles
{
cyclics
{
type faceZone;
zoneName cyclicFaces;
owner
{
name cyclicLeft;
type cyclic;
neighbourPatch cyclicRight;
}
neighbour
{
name cyclicRight;
type cyclic;
neighbourPatch cyclicLeft;
}
}
}
Note that the 'patches' sub-dictionary is not needed any more; the
'owner' and 'neighbour' sub-dictionaries can be in the same dictionary
as the parameters with which faces are selected. For backwards
compatibility, however, a 'patches' sub-dictionary is still permitted,
as are keywords 'master' and 'slave' (in place of 'owner' and
'neighbour', respectively).
The 'patchPairs' syntax has been removed. Whilst consise, this syntax
made a number of assumptions and decisions regarding naming conventions
that were not sufficiently intuitive for the user to understand without
extensive reference to the code. If identical boundaries are desired on
both sides of the patch, dictionary substitution provides a more
intuitive way of minimising the amount of specifiection required. For
example, to create two back-to-back walls, the following specification
could be used:
internalFacesOnly true;
fields true;
baffles
{
walls
{
type faceZone;
zoneName wallFaces;
owner
{
name baffleWallLeft;
type wall;
patchFields
{
p
{
type zeroGradient;
}
U
{
type noSlip;
}
}
}
neighbour
{
name baffleWallRight;
$owner; // <-- Use the same settings as for the owner
}
}
}
This boundary condition no longer stores its own mapping. It now has to
be applied to a mapped wall (or equivalent) patch, which does the
mapping for it. This ensures that mapping information is shared between
multiple fields, and that redundant copies are not generated.
The 'pointSync' setting in createPatchDict is now optional and defaults
to false. This setting is very rarely used. A number of unused
'createPatchDict' files have also been removed and obsolete information
has been removed from the annotated example dictionaries.
The defaultPatch type currently defaults to empty which is appropriate for 1D
and 2D cases but not when creating the initial blockMesh for snappyHexMesh as
the presence of empty patches triggers the inappropriate application of 2D point
constraint corrections following snapping and morphing. To avoid this hidden
problem a warning is now generated from blockMesh when the defaultPatch is not
explicitly set for cases which generate a default patch, i.e. for which the
boundary is not entirely defined. e.g.
.
.
.
Creating block mesh topology
--> FOAM FATAL IO ERROR:
The 'defaultPatch' type must be specified for the 'defaultFaces' patch, e.g. for snappyHexMesh
defaultPatch
{
name default; // optional
type patch;
}
or for 2D meshes
defaultPatch
{
name frontAndBack; // optional
type empty;
}
.
.
.
All the tutorials have been update to include the defaultPatch specification as
appropriate.
The unreliable extrapolateProfile option has been replaced by the more flexible
and reliable profile option which allows the velocity profile to be specified as
a Function1 of the normalised distance to the wall. To simplify the
specification of the most common velocity profiles the new laminarBL (quadratic
profile) and turbulentBL (1/7th power law) Function1s are provided.
In addition to the new profile option the flow rate can now be specified as a
meanVelocity, volumetricFlowRate or massFlowRate, all of which are Function1s of
time.
The following tutorials have been updated to use the laminarBL profile:
multiphase/multiphaseEulerFoam/laminar/titaniaSynthesis
multiphase/multiphaseEulerFoam/laminar/titaniaSynthesisSurface
The following tutorials have been updated to use the turbulentBL profile:
combustion/reactingFoam/Lagrangian/verticalChannel
combustion/reactingFoam/Lagrangian/verticalChannelLTS
combustion/reactingFoam/Lagrangian/verticalChannelSteady
compressible/rhoPimpleFoam/RAS/angledDuct
compressible/rhoPimpleFoam/RAS/angledDuctLTS
compressible/rhoPimpleFoam/RAS/squareBendLiq
compressible/rhoPorousSimpleFoam/angledDuctImplicit
compressible/rhoSimpleFoam/angledDuctExplicitFixedCoeff
compressible/rhoSimpleFoam/squareBend
compressible/rhoSimpleFoam/squareBendLiq
heatTransfer/chtMultiRegionFoam/shellAndTubeHeatExchanger
heatTransfer/chtMultiRegionFoam/shellAndTubeHeatExchanger
incompressible/porousSimpleFoam/angledDuctImplicit
incompressible/porousSimpleFoam/straightDuctImplicit
multiphase/interFoam/RAS/angledDuct
Class
Foam::flowRateInletVelocityFvPatchVectorField
Description
Velocity inlet boundary condition creating a velocity field with
optionally specified profile normal to the patch adjusted to match the
specified mass flow rate, volumetric flow rate or mean velocity.
For a mass-based flux:
- the flow rate should be provided in kg/s
- if \c rho is "none" the flow rate is in m3/s
- otherwise \c rho should correspond to the name of the density field
- if the density field cannot be found in the database, the user must
specify the inlet density using the \c rhoInlet entry
For a volumetric-based flux:
- the flow rate is in m3/s
Usage
\table
Property | Description | Required | Default value
massFlowRate | Mass flow rate [kg/s] | no |
volumetricFlowRate | Volumetric flow rate [m^3/s]| no |
meanVelocity | Mean velocity [m/s]| no |
profile | Velocity profile | no |
rho | Density field name | no | rho
rhoInlet | Inlet density | no |
alpha | Volume fraction field name | no |
\endtable
Example of the boundary condition specification for a volumetric flow rate:
\verbatim
<patchName>
{
type flowRateInletVelocity;
volumetricFlowRate 0.2;
profile laminarBL;
}
\endverbatim
Example of the boundary condition specification for a mass flow rate:
\verbatim
<patchName>
{
type flowRateInletVelocity;
massFlowRate 0.2;
profile turbulentBL;
rho rho;
rhoInlet 1.0;
}
\endverbatim
Example of the boundary condition specification for a volumetric flow rate:
\verbatim
<patchName>
{
type flowRateInletVelocity;
meanVelocity 5;
profile turbulentBL;
}
\endverbatim
The \c volumetricFlowRate, \c massFlowRate or \c meanVelocity entries are
\c Function1 of time, see Foam::Function1s.
The \c profile entry is a \c Function1 of the normalised distance to the
wall. Any suitable Foam::Function1s can be used including
Foam::Function1s::codedFunction1 but Foam::Function1s::laminarBL and
Foam::Function1s::turbulentBL have been created specifically for this
purpose and are likely to be appropriate for most cases.
Note
- \c rhoInlet is required for the case of a mass flow rate, where the
density field is not available at start-up
- The value is positive into the domain (as an inlet)
- May not work correctly for transonic inlets
- Strange behaviour with potentialFoam since the U equation is not solved
See also
Foam::fixedValueFvPatchField
Foam::Function1s::laminarBL
Foam::Function1s::turbulentBL
Foam::Function1s
Foam::flowRateOutletVelocityFvPatchVectorField
used in conjunction with the new loadBalancing option in constant/chemistryProperties:
loadBalancing on;
which enables per-cell CPU time caching used by the loadBalancer to redistribute
the mesh. Currently this option is only provided for chemistry integration but
the implementation is general and in future options will be provided to balance
other local cell loads, in particular Lagrangian particles.
The loadBalancer in enabled by specifying a distributor entry in
constant/dynamicMeshDict, e.g.
distributor
{
type loadBalancer;
libs ("libfvMeshDistributors.so");
multiConstraint true;
// How often to redistribute
redistributionInterval 10;
// Maximum fractional cell distribution imbalance
// before rebalancing
maxImbalance 0.1;
}
with which the mesh is checked for more than 10% load-imbalance every 10
time-steps and redistributed using a multi-constraint method, i.e. separate CPU
load weights are provided for each of the loads, currently that is the chemistry
integration load and the CPU time taken for the rest of the simulation,
transport equations solution etc.
The fvMeshDistributors::loadBalancer uses the distributor specified in
system/decomposeParDict to redistribute the mesh based on the cell CPU loads,
e.g. to use the Zoltan RCB method specify:
distributor zoltan;
libs ("libzoltanDecomp.so");
zoltanCoeffs
{
lb_method rcb;
}
Unfortunately only a few available redistribution methods support
multi-constraints: Zoltan::RCB, MeTiS, parMeTiS and xtraPuLP, of these only
Zoltan::RCB is currently available in OpenFOAM. Load-balancing is possible
without using a multi-constraint method (i.e. using any of the other
decomposition methods provided with OpenFOAM and Zoltan) by summing the various
CPU loads which is selected by setting:
multiConstraint false;
but the load-balancing is likely to be a lot less effective with this option.
Due to the licencing issues with parMeTiS interfacing to xtraPuLP might be the
best option for further work on load-balancing in OpenFOAM, or MeTiS could be
used in parallel by first agglomerating the distribution graph on the master
processor and redistributing the result; this pseudo-parallel option is already
provided for the Scotch method.
Now that Cp and Cv are cached it is more convenient and consistent and slightly
more efficient to cache thermal conductivity kappa rather than thermal
diffusivity alpha which is not a fundamental property, the appropriate form
depending on the energy solved for. kappa is converted into the appropriate
thermal diffusivity for the energy form solved for by dividing by the
corresponding cached heat capacity when required, which is efficient.
There is no longer any need for the surfaceFilmModel abstract base class and
"New" selection method as surface films are now handled within the fvModel
framework. This makes the surfaceFilmModel entry in the surfaceFilmProperties
dictionary redundant.
The surfaceFilm and VoFSurfaceFilm fvModels now instantiate a thermoSingleLayer
providing direct access to all the film functions, simplifying the
implementation better ensuring consistency between the film and primary region
equations.
When snappyHexMesh is run in parallel it re-balances the mesh during refinement
and layer addition by redistribution which requires a decomposition method
that operates in parallel, e.g. hierachical or ptscotch. decomposePar uses a
decomposition method which operates in serial e.g. hierachical but NOT
ptscotch. In order to run decomposePar followed by snappyHexMesh in parallel it
has been necessary to change the method specified in decomposeParDict but now
this is avoided by separately specifying the decomposition and distribution
methods, e.g. in the incompressible/simpleFoam/motorBike case:
numberOfSubdomains 6;
decomposer hierarchical;
distributor ptscotch;
hierarchicalCoeffs
{
n (3 2 1);
order xyz;
}
The distributor entry is also used for run-time mesh redistribution, e.g. in the
multiphase/interFoam/RAS/floatingObject case re-distribution for load-balancing
is enabled in constant/dynamicMeshDict:
distributor
{
type distributor;
libs ("libfvMeshDistributors.so");
redistributionInterval 10;
}
which uses the distributor specified in system/decomposeParDict:
distributor hierarchical;
This rationalisation provides the structure for development of mesh
redistribution and load-balancing.
With the addition of mesh-motion to XiFoam and the new engine fvMeshMover the
XiEngineFoam kivaTest simple IC engine example now runs in XiFoam and
XiEngineFoam has been removed. This simplifies maintenance provides greater
extensibility.
replacing the virtual functions overridden in engineTime.
Now the userTime conversion function in Time is specified in system/controlDict
such that the solver as well as all pre- and post-processing tools also operate
correctly with the chosen user-time.
For example the user-time and rpm in the tutorials/combustion/XiEngineFoam/kivaTest case are
now specified in system/controlDict:
userTime
{
type engine;
rpm 1500;
}
The default specification is real-time:
userTime
{
type real;
}
but this entry can be omitted as the real-time class is instantiated
automatically if the userTime entry is not present in system/controlDict.
Mesh motion and topology change are now combinable run-time selectable options
within fvMesh, replacing the restrictive dynamicFvMesh which supported only
motion OR topology change.
All solvers which instantiated a dynamicFvMesh now instantiate an fvMesh which
reads the optional constant/dynamicFvMeshDict to construct an fvMeshMover and/or
an fvMeshTopoChanger. These two are specified within the optional mover and
topoChanger sub-dictionaries of dynamicFvMeshDict.
When the fvMesh is updated the fvMeshTopoChanger is first executed which can
change the mesh topology in anyway, adding or removing points as required, for
example for automatic mesh refinement/unrefinement, and all registered fields
are mapped onto the updated mesh. The fvMeshMover is then executed which moved
the points only and calculates the cell volume change and corresponding
mesh-fluxes for conservative moving mesh transport. If multiple topological
changes or movements are required these would be combined into special
fvMeshMovers and fvMeshTopoChangers which handle the processing of a list of
changes, e.g. solidBodyMotionFunctions:multiMotion.
The tutorials/multiphase/interFoam/laminar/sloshingTank3D3DoF case has been
updated to demonstrate this new functionality by combining solid-body motion
with mesh refinement/unrefinement:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: dev
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
location "constant";
object dynamicMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
mover
{
type motionSolver;
libs ("libfvMeshMovers.so" "libfvMotionSolvers.so");
motionSolver solidBody;
solidBodyMotionFunction SDA;
CofG (0 0 0);
lamda 50;
rollAmax 0.2;
rollAmin 0.1;
heaveA 4;
swayA 2.4;
Q 2;
Tp 14;
Tpn 12;
dTi 0.06;
dTp -0.001;
}
topoChanger
{
type refiner;
libs ("libfvMeshTopoChangers.so");
// How often to refine
refineInterval 1;
// Field to be refinement on
field alpha.water;
// Refine field in between lower..upper
lowerRefineLevel 0.001;
upperRefineLevel 0.999;
// Have slower than 2:1 refinement
nBufferLayers 1;
// Refine cells only up to maxRefinement levels
maxRefinement 1;
// Stop refinement if maxCells reached
maxCells 200000;
// Flux field and corresponding velocity field. Fluxes on changed
// faces get recalculated by interpolating the velocity. Use 'none'
// on surfaceScalarFields that do not need to be reinterpolated.
correctFluxes
(
(phi none)
(nHatf none)
(rhoPhi none)
(alphaPhi.water none)
(meshPhi none)
(meshPhi_0 none)
(ghf none)
);
// Write the refinement level as a volScalarField
dumpLevel true;
}
// ************************************************************************* //
Note that currently this is the only working combination of mesh-motion with
topology change within the new framework and further development is required to
update the set of topology changers so that topology changes with mapping are
separated from the mesh-motion so that they can be combined with any of the
other movements or topology changes in any manner.
All of the solvers and tutorials have been updated to use the new form of
dynamicMeshDict but backward-compatibility was not practical due to the complete
reorganisation of the mesh change structure.
for consistency with the regionToCell topo set source and splitMeshRegions and
provides more logical extension to the multiple and outside point variants insidePoints,
outsidePoint and outsidePoints.
To simplify maintenance and further development of chemistry solution the
standardChemistryModel and TDACChemistryModel have been merged into the single
chemistryModel class. Now the TDAC mechanism reduction and tabulation
components can be individually selected or set to "none" or the corresponding
entries in the chemistryProperties dictionary omitted to switch them off thus
reproducing the behaviour of the standardChemistryModel.
For example the following chemistryProperties includes TDAC:
#includeEtc "caseDicts/solvers/chemistry/TDAC/chemistryProperties.cfg"
chemistryType
{
solver ode;
}
chemistry on;
initialChemicalTimeStep 1e-7;
odeCoeffs
{
solver seulex;
absTol 1e-8;
relTol 1e-1;
}
reduction
{
tolerance 1e-4;
}
tabulation
{
tolerance 3e-3;
}
#include "reactionsGRI"
and to run without TDAC the following is sufficient:
chemistryType
{
solver ode;
}
chemistry on;
initialChemicalTimeStep 1e-7;
odeCoeffs
{
solver seulex;
absTol 1e-8;
relTol 1e-1;
}
#include "reactionsGRI"
or the "reduction" and "tabulation" entries can be disabled explicitly:
#includeEtc "caseDicts/solvers/chemistry/TDAC/chemistryProperties.cfg"
chemistryType
{
solver ode;
}
chemistry on;
initialChemicalTimeStep 1e-7;
odeCoeffs
{
solver seulex;
absTol 1e-8;
relTol 1e-1;
}
reduction
{
method none;
tolerance 1e-4;
}
tabulation
{
method none;
tolerance 3e-3;
}
#include "reactionsGRI"
Changed the laminar methane combustion cases to use the Wilke mixing rule for
the transport properties obtained from the Sutherland model but with coefficient
mixing for thermodynamic properties for efficient evaluation of reaction
equilibria.
This provides significantly more accurate results for laminar combustion,
producing a thinner flame and a 10K reduction in peak temperature.
to provide a single consistent code and user interface to the specification of
physical properties in both single-phase and multi-phase solvers. This redesign
simplifies usage and reduces code duplication in run-time selectable solver
options such as 'functionObjects' and 'fvModels'.
* physicalProperties
Single abstract base-class for all fluid and solid physical property classes.
Physical properties for a single fluid or solid within a region are now read
from the 'constant/<region>/physicalProperties' dictionary.
Physical properties for a phase fluid or solid within a region are now read
from the 'constant/<region>/physicalProperties.<phase>' dictionary.
This replaces the previous inconsistent naming convention of
'transportProperties' for incompressible solvers and
'thermophysicalProperties' for compressible solvers.
Backward-compatibility is provided by the solvers reading
'thermophysicalProperties' or 'transportProperties' if the
'physicalProperties' dictionary does not exist.
* phaseProperties
All multi-phase solvers (VoF and Euler-Euler) now read the list of phases and
interfacial models and coefficients from the
'constant/<region>/phaseProperties' dictionary.
Backward-compatibility is provided by the solvers reading
'thermophysicalProperties' or 'transportProperties' if the 'phaseProperties'
dictionary does not exist. For incompressible VoF solvers the
'transportProperties' is automatically upgraded to 'phaseProperties' and the
two 'physicalProperties.<phase>' dictionary for the phase properties.
* viscosity
Abstract base-class (interface) for all fluids.
Having a single interface for the viscosity of all types of fluids facilitated
a substantial simplification of the 'momentumTransport' library, avoiding the
need for a layer of templating and providing total consistency between
incompressible/compressible and single-phase/multi-phase laminar, RAS and LES
momentum transport models. This allows the generalised Newtonian viscosity
models to be used in the same form within laminar as well as RAS and LES
momentum transport closures in any solver. Strain-rate dependent viscosity
modelling is particularly useful with low-Reynolds number turbulence closures
for non-Newtonian fluids where the effect of bulk shear near the walls on the
viscosity is a dominant effect. Within this framework it would also be
possible to implement generalised Newtonian models dependent on turbulent as
well as mean strain-rate if suitable model formulations are available.
* visosityModel
Run-time selectable Newtonian viscosity model for incompressible fluids
providing the 'viscosity' interface for 'momentumTransport' models.
Currently a 'constant' Newtonian viscosity model is provided but the structure
supports more complex functions of time, space and fields registered to the
region database.
Strain-rate dependent non-Newtonian viscosity models have been removed from
this level and handled in a more general way within the 'momentumTransport'
library, see section 'viscosity' above.
The 'constant' viscosity model is selected in the 'physicalProperties'
dictionary by
viscosityModel constant;
which is equivalent to the previous entry in the 'transportProperties'
dictionary
transportModel Newtonian;
but backward-compatibility is provided for both the keyword and model
type.
* thermophysicalModels
To avoid propagating the unnecessary constructors from 'dictionary' into the
new 'physicalProperties' abstract base-class this entire structure has been
removed from the 'thermophysicalModels' library. The only use for this
constructor was in 'thermalBaffle' which now reads the 'physicalProperties'
dictionary from the baffle region directory which is far simpler and more
consistent and significantly reduces the amount of constructor code in the
'thermophysicalModels' library.
* compressibleInterFoam
The creation of the 'viscosity' interface for the 'momentumTransport' models
allows the complex 'twoPhaseMixtureThermo' derived from 'rhoThermo' to be
replaced with the much simpler 'compressibleTwoPhaseMixture' derived from the
'viscosity' interface, avoiding the myriad of unused thermodynamic functions
required by 'rhoThermo' to be defined for the mixture.
Same for 'compressibleMultiphaseMixture' in 'compressibleMultiphaseInterFoam'.
This is a significant improvement in code and input consistency, simplifying
maintenance and further development as well as enhancing usability.
Henry G. Weller
CFD Direct Ltd.
For a set to zone conversion the name of the zone is now specified with the
'zone' keyword.
For a patch to set conversion the name of the patch is now specified with the
'patch' keyword.
Backward-compatibility is supported for both these changes.
Additionally the file name of a searchableSurface file is specified with the
'file' keyword. This should be 'surface' but that keyword is currently and
confusingly used for the surface type rather than name and this cannot be
changed conveniently while maintaining backward compatibility.
and only needed if there is a name clash between entries in the source
specification and the set specification, e.g. "name":
{
name rotorCells;
type cellSet;
action new;
source zoneToCell;
sourceInfo
{
name cylinder;
}
}
topoSet is a more flexible and extensible replacement for setSet using standard
OpenFOAM dictionary input format rather than the limited command-line input
format developed specifically for setSet. This replacement allows for the
removal of a significant amount of code simplifying maintenance and the addition
of more topoSet sources.
Removed the combustion/reactingFoam/Lagrangian/counterFlowFlame2DLTS
case as it was originally a consistency check between reactingFoam and
reactingParcelFoam. It is not necessary now these solvers have been
combined.
Removed an unused fvModels file in the
reactingFoam/Lagrangian/simplifiedSiwek tutorial.
A number of changes have been made to the surfaceFieldValue and
volFieldValue function objects to improve their usability and
performance, and to extend them so that similar duplicate functionality
elsewhere in OpenFOAM can be removed.
Weighted operations have been removed. Weighting for averages and sums
is now triggered simply by the existence of the "weightField" or
"weightFields" entry. Multiple weight fields are now supported in both
functions.
The distinction between oriented and non-oriented fields has been
removed from surfaceFieldValue. There is now just a single list of
fields which are operated on. Instead of oriented fields, an
"orientedSum" operation has been added, which should be used for
flowRate calculations and other similar operations on fluxes.
Operations minMag and maxMag have been added to both functions, to
calculate the minimum and maximum field magnitudes respectively. The min
and max operations are performed component-wise, as was the case
previously.
In volFieldValue, minMag and maxMag (and min and mag operations when
applied to scalar fields) will report the location, cell and processor
of the maximum or minimum value. There is also a "writeLocation" option
which if set will write this location information into the output file.
The fieldMinMax function has been made obsolete by this change, and has
therefore been removed.
surfaceFieldValue now operates in parallel without accumulating the
entire surface on the master processor for calculation of the operation.
Collecting the entire surface on the master processor is now only done
if the surface itself is to be written out.
With this change both
blockMesh -dict fineBlockMeshDict
blockMesh -dict system/fineBlockMeshDict
are supported, if the system/ path is not specified it is assumed
Settings for the particleTracks utility are now specified in
system/particleTracksDict. Correspondingly, settings for
steadyParticleTracks are now specified in
system/steadyParticleTracksDict.
When using 'simple' or 'hierarchical' decomposition it is useful to slightly rotate a
coordinate-aligned block-mesh to improve the processor boundaries by avoiding
irregular cell distribution at those boundaries. The degree of slight rotation
is controlled by the 'delta' coefficient and a value of 0.001 is generally
suitable so to avoid unnecessary clutter in 'decomposeParDict' 'delta' now
defaults to this value.
The FOAM file format has not changed from version 2.0 in many years and so there
is no longer a need for the 'version' entry in the FoamFile header to be
required and to reduce unnecessary clutter it is now optional, defaulting to the
current file format 2.0.
The pressure work term for total internal energy is div(U p) which can be
discretised is various ways, given a mass flux field phi it seems logical to
implement it in the form div(phi/interpolate(rho), p) but this is not exactly
consistent with the relationship between enthalpy and internal energy (h = e +
p/rho) and the transport of enthalpy, it would be more consistent to implement
it in the form div(phi, p/rho). A further improvement in consistency can be
gained by using the same convection scheme for this work term and the convection
term div(phi, e) and for reacting solvers this is easily achieved by using the
multi-variate limiter mvConvection provided for energy and specie convection.
This more consistent total internal energy work term has now been implemented in
all the compressible and reacting flow solvers and provides more accurate
solutions when running with internal energy, particularly for variable density
mixing cases with small pressure variation.
For non-reacting compressible solvers this improvement requires a change to the
corresponding divScheme in fvSchemes:
div(phiv,p) -> div(phi,(p|rho))
and all the tutorials have been updated accordingly.
for buoyant solvers buoyantPimpleFoam, buoyantSimpleFoam and
buoyantReactingFoam:
Class
Foam::hydrostaticInitialisation
Description
Optional hydrostatic initialisation of p_rgh and p by solving for and
caching the hydrostatic ph_rgh and updating the density such that
p = ph_rgh + rho*gh + pRef
This initialisation process is applied at the beginning of the run (not on
restart) if the \c hydrostaticInitialisation switch is set true in
fvSolution/PIMPLE or fvSolution/SIMPLE. The calculation is iterative if the
density is a function of pressure and an optional number of iterations \c
nHydrostaticCorrectors may be specified which defaults to 5.
The fireFoam solver has solver has been replaced by the more general
buoyantReactingFoam solver, which supports buoyant compressible reacting flow
coupled to multiple run-time-selectable lagrangian clouds and surface film
modelling and optional hydrostatic initialisation of the pressure and p_rgh.
Hydrostatic initialisation of the pressure fields is useful for large fires in
open domains where the stability of the initial flow is dominated by the initial
pressure distribution in the domain and at the boundaries. The optional
hydrostaticInitialization switch in fvSolution/PIMPLE with
nHydrostaticCorrectors enables hydrostatic initialisation, e.g.
PIMPLE
{
momentumPredictor yes;
nOuterCorrectors 1;
nCorrectors 2;
nNonOrthogonalCorrectors 0;
hydrostaticInitialization yes;
nHydrostaticCorrectors 5;
}
and the resulting ph_rgh field can be used with the prghTotalHydrostaticPressure
p_rgh boundary condition to apply this hydrostatic pressure distribution at the
boundaries throughout the simulation.
See the following cases for examples transferred from fireFoam:
$FOAM_TUTORIALS/combustion/buoyantReactingFoam/RAS
