The surfaceFilm fvModel has been renamed surfaceFilms, and can now have
a number of independent film models specified.
For example, the hotBoxes tutorial could be modified to have separate
film regions for the boxes and for the floor. In which case, the names
of the separate films would need specifying as shown below.
surfaceFilms
{
type surfaceFilms;
surfaceFilms (boxesFilm floorFilm); // <-- new entry
libs ("libsurfaceFilmModels.so");
}
The old fvModel name, surfaceFilm, has been maintained for backwards
compatibility.
The Lagrangian surface film model now also requires the coupled
surfaceFilms to be specified when there is not just a single
default-named film. For example, in constant/cloudProperties:
subModels
{
surfaceFilmModel thermoSurfaceFilm;
thermoSurfaceFilmCoeffs
{
surfaceFilms (boxesFilm floorFilm); // <-- new entry
interactionType splashBai;
deltaWet 0.0005;
Adry 2630;
Awet 1320;
Cf 0.6;
}
...
}
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
For example, 'foamInfo RosinRammler' includes in the output:
Model
This appears to be the 'RosinRammler' model of the 'distributionModels' family.
The models in the 'distributionModels' family are:
+ exponential
+ fixedValue
+ general
+ massRosinRammler
+ multiNormal
+ normal
+ RosinRammler
+ uniform
The new fvModels is a general interface to optional physical models in the
finite volume framework, providing sources to the governing conservation
equations, thus ensuring consistency and conservation. This structure is used
not only for simple sources and forces but also provides a general run-time
selection interface for more complex models such as radiation and film, in the
future this will be extended to Lagrangian, reaction, combustion etc. For such
complex models the 'correct()' function is provided to update the state of these
models at the beginning of the PIMPLE loop.
fvModels are specified in the optional constant/fvModels dictionary and
backward-compatibility with fvOption is provided by reading the
constant/fvOptions or system/fvOptions dictionary if present.
The new fvConstraints is a general interface to optional numerical constraints
applied to the matrices of the governing equations after construction and/or to
the resulting field after solution. This system allows arbitrary changes to
either the matrix or solution to ensure numerical or other constraints and hence
violates consistency with the governing equations and conservation but it often
useful to ensure numerical stability, particularly during the initial start-up
period of a run. Complex manipulations can be achieved with fvConstraints, for
example 'meanVelocityForce' used to maintain a specified mean velocity in a
cyclic channel by manipulating the momentum matrix and the velocity solution.
fvConstraints are specified in the optional system/fvConstraints dictionary and
backward-compatibility with fvOption is provided by reading the
constant/fvOptions or system/fvOptions dictionary if present.
The separation of fvOptions into fvModels and fvConstraints provides a rational
and consistent separation between physical and numerical models which is easier
to understand and reason about, avoids the confusing issue of location of the
controlling dictionary file, improves maintainability and easier to extend to
handle current and future requirements for optional complex physical models and
numerical constraints.
The subject can relate to models (including boundary conditions and
packaged function objects), applications and scripts. For example:
foamInfo simpleFoam
foamInfo kEpsilon
foamInfo turbulentIntensityKineticEnergyInlet
foamInfo fixedTemperatureConstraint
foamInfo surfaces
foamInfo foamNewBC
The output includes the following:
- File: the location of the relevant source code header file;
- Description details from the header file;
- Usage details from the header file;
- Examples: a list of relevant cases from the tutorials directory.
foamInfo includes the -web|-w and -browser|-b options to open relevant
HTML source code documentation at https://cpp.openfoam.org
Chris Greenshields, CFD Direct
