foamMonitor has new options to select columns of data, plot the data on
x-axis and the independent variable on y-axis, and to display a single
graph without refreshing periodically. It also now terminates cleanly,
removing the gnuplot processes behind it.
New options:
-columns | -c <cols> display specfied columns, comma-separated, e.g. 2,4
-flip | -f plot data on x-axis, independent variable on y-axis
-once | -o print a graph one time without refreshing
This mesh mover facilitates explicit node translation based on scaled distance
functions for the providing smooth deformation of the mesh to accommodate the
motion piston and multiple valves present in IC engines. and run-time mesh-to-mesh mapping used to avoid
extreme mesh distortion and support the necessary topology changes that occur at
valve closure.
Highlighted features include:
* Piston motion based on user-defined functions, with options for standard crank
and connecting rod motion.
* Valve motion based on user-provided lift data or table.
* Support for linerPatches, slidingPatches, and frozenZones.
* Non-conformal coupled (NCC) interfaces can be used to provide better control
of the mesh-motion around valves
* Run-time mesh-to-mesh mapping used to avoid extreme mesh distortion and
support the necessary topology changes that occur at valve closure
* Control over mesh motion per moving object including motion parameters and layer
thickness.
Description from the multiValveEngine.H file:
A mesh mover using explicit node translation based on scaled distance
functions per moving object. The mover supports any number of valves
together with piston motion and following features:
- Piston motion: Function1 of user-time, may be set to
crankConnectingRodMotion for standard crank and connecting rod motion.
- Valve motion: Function1, may be set to table if the valve lift date is
provided in the form of a table.
- Smooth mesh motion between a moving object and other patches.
- linerPatches: the set of patches corresponding to the cylinder liner
Used by createEngineZones
- slidingPatches: a set of patches along which mesh is allowed
to deform. For example, on the cylinder liner, it is desired to
slide mesh nodes while piston is moving.
- frozenZones: list of pointZones the points of which are frozen,
i.e. do not move.
- Run-time clearance estimation based on patch-to-patch distances printed.
- Supports cellSet and cellZone definitions to restrict mesh motion.
- Supports domains with nonConformalCoupling (NCC) interfaces,
enabling e.g. nodes to slide along with the interface.
- Closing the valve can be achieved by meshToMesh mapping onto a new
grid with closed valve geometry at user given time.
- Mesh motion can be controlled per moving object by setting:
- patches: list of patches defining the object.
- motion: a Function1 which returns the object position
as a function of time.
- movingZones: list of pointZones the points of which move with the
object.
- maxMotionDistance: a distance away from the moving object
after nodes are not allowed to move. (Default inf.)
- movingFrozenLayerThickness: thickness of layer in which points move
with the moving object. (Default 0)
- staticFrozenLayerThickness: thickness of layer in which points
are fixed with respect to static patches (e.g. walls). (Default 0)
- cosineScaling: a switch whether nodal translation is weighted by
its distance from the moving object. The objective is to yield less
deformation near the moving object and sustain e.g. boundary layer.
(Default no, i.e. linear weighting)
- fractionalTravelInterval: fraction of the stroke travelled after
which the cached motion scaling weights are recalculated
For valve object only:
- minLift: a minimum valve lift value after considered closed.
Some of the above parameters are highlighted in a given schematic
piston-valve configuration w.r.t entries used to control piston motion.
Furthermore, an example dictionary entries are provided below.
| | | |
| | | |
| | S | |
| | T | |
| | E | |
| | M | |
/ | | \
/ | | \
/ | | \
_____________/ | | \_____________
| : | | : |
| : /``````````````` ```````````````\ : |
| : / VALVE HEAD \ : |
| L : /_____________________________________________\ : |
| I : /\ : |
| N : || staticFrozenLayerThickness : |
| E : NCC (optional) \/ (w.r.t. piston motion) : |
| R : `````````` : |
| : : |
| : : |
|........:.......................................................:........|
| : /\ : |
| : || movingFrozenLayerThickness : |
|________:_________________________\/____________________________:________|
PISTON
\verbatim
mover
{
type multiValveEngine;
libs ("libfvMeshMoversMultiValveEngine.so");
frozenZones (frozenZone1 frozenZone2);
slidingPatches
(
liner
valveStem
"nonCouple.*"
);
linerPatches (liner);
piston
{
patches (piston);
axis (0 0 1);
motion
{
type crankConnectingRodMotion;
conRodLength 1e3;
stroke 1.0;
}
// Move the points in the piston bowl with the piston
movingZones (pistonBowl);
// Optional
maxMotionDistance 1e30;
movingFrozenLayerThickness 0;
staticFrozenLayerThickness 0;
fractionalTravelInterval 0.1;
cosineScaling yes;
}
valves
{
iv
{
patches (valveHead);
axis (0 0 1);
// Optional
maxMotionDistance 1e30;
movingFrozenLayerThickness 0;
staticFrozenLayerThickness 0;
fractionalTravelInterval 0.1;
cosineScaling yes;
minLift 0.001;
motion
{
type table;
values
(
(0 0)
(480 0.1)
(720 0)
);
// For multi-cycle simulations, use repeat
outOfBounds repeat;
interpolationScheme linear;
}
}
}
}
\endverbatim
Note:
The implementation utilises pointDist objects for distance computation,
resulting distance fields do not propagate through NCC interfaces. Hence,
there should be no horizontal NCC interface separating piston from
cylinder head as it would result in potentially ill defined mesh
deformation. Due to same feature, in a schematic case setup above, valve
motion affects only cells between NCC patches even though no cellSet is
explicitly defined.
SourceFiles
multiValveEngine.C
Patch contributed by:
* Heikki Kahila, Wärtsilä Finland: Original implementation
* Bulut Tekgül, Wärtsilä Finland: Testing, cleanup, help with refactoring
* Henry Weller, CFD Direct: Refactoring, generalisation, optimisation and
merging into OpenFOAM
for consistency with fvModels and fvConstraints, to simplify code and case
maintenance and to avoid the potentially complex functions entries being
unnecessarily parsed by utilities for which functionObject evaluation is
disabled.
The functions entry in controlDict is still read if the functions file is not
present for backward-compatibility, but it is advisable to migrate cases to use
the new functions file.
This change makes multiphaseEuler more consistent with other modules and
makes its sub-libraries less inter-dependent. Some left-over references
to multiphaseEulerFoam have also been removed.
The following commands are now possible. Note that the '$' sigil on the
FOAM_TUTORIALS environment variable has been escaped with '\' to prevent
it from being expanded to nothing in the outer/interactive shell.
~/OpenFOAM/OpenFOAM-dev/bin/foamExec ls \$FOAM_TUTORIALS/*
~/OpenFOAM/OpenFOAM-dev/bin/foamExec cp -r \$FOAM_TUTORIALS/incompressibleFluid/pitzDaily .
This avoids potential hidden run-time errors caused by solvers running with
boundary conditions which are not fully specified. Note that "null-constructor"
here means the constructor from patch and internal field only, no data is
provided.
Constraint and simple BCs such as 'calculated', 'zeroGradient' and others which
do not require user input to fully specify their operation remain on the
null-constructor table for the construction of fields with for example all
'calculated' or all 'zeroGradient' BCs.
A special version of the 'inletOutlet' fvPatchField named 'zeroInletOutlet' has
been added in which the inlet value is hard-coded to zero which allows this BC
to be included on the null-constructor table. This is useful for the 'age'
functionObject to avoid the need to provide the 'age' volScalarField at time 0
unless special inlet or outlet BCs are required. Also for isothermalFilm in
which the 'alpha' field is created automatically from the 'delta' field if it is
not present and can inherit 'zeroInletOutlet' from 'delta' if appropriate. If a
specific 'inletValue' is require or other more complex BCs then the 'alpha'
field file must be provided to specify these BCs as before.
Following this improvement it will now be possible to remove the
null-constructors from all fvPatchFields not added to the null-constructor
table, which is most of them, thus reducing the amount of code and maintenance
overhead and making easier and more obvious to write new fvPatchField types.
The new general multi-region framework using the isothermalFilm and film solver
modules and executed with foamMultiRun is a much more flexible approach to the
inclusion of liquid films in simulations with the support for coupling to other
regions of various types e.g. gas flows, Lagrangian clouds, VoF, CHT etc. This
has all been achieved with a significant reduction in the number of lines of
code and significant improvements in code structure, readability and
maintainability.
executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations. Replaces driftFluxFoam and all the corresponding
tutorials have been updated and moved to
tutorials/modules/incompressibleDriftFlux.
Class
Foam::solvers::incompressibleDriftFlux
Description
Solver module for 2 incompressible fluids using the mixture approach with
the drift-flux approximation for relative motion of the phases, 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 with mixture transport modelling in which a
single laminar, RAS or LES model is selected to model the momentum stress.
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
incompressibleDriftFlux.C
See also
Foam::solvers::VoFSolver
Foam::solvers::twoPhaseVoFSolver
Foam::solvers::compressibleVoF
compressibleVoF supports cavitation fvModels which provide a more physical and
controllable approach to cavitation modelling than the simple homogeneous
equilibrium approximation used in cavitatingFoam.
The tutorials/multiphase/cavitatingFoam/RAS/throttle case has been converted to
tutorials/modules/compressibleVoF/throttle which demonstrates how to update
cases from cavitatingFoam to compressibleVoF.
A cavitatingFoam script is provided to redirect users to update their cases to
compressibleVoF.
executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations. Replaces denseParticleFoam and all the corresponding
tutorials have been updated and moved to
tutorials/modules/incompressibleDenseParticleFluid.
Class
Foam::solvers::incompressibleDenseParticleFluid
Description
Solver module for transient flow of incompressible isothermal fluids coupled
with particle clouds including the effect of the volume fraction of
particles on the continuous phase, with optional mesh motion and change.
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, constraining or limiting
the solution.
The keyword 'select' is now used to specify the cell, face or point set
selection method consistently across all classes requiring this functionality.
'select' replaces the inconsistently named 'regionType' and 'selectionMode'
keywords used previously but backwards-compatibility is provided for user
convenience. All configuration files and tutorials have been updated.
Examples of 'select' from the tutorial cases:
functionObjects:
cellZoneAverage
{
type volFieldValue;
libs ("libfieldFunctionObjects.so");
writeControl writeTime;
writeInterval 1;
fields (p);
select cellZone;
cellZone injection;
operation volAverage;
writeFields false;
}
#includeFunc populationBalanceSizeDistribution
(
name=numberDensity,
populationBalance=aggregates,
select=cellZone,
cellZone=outlet,
functionType=numberDensity,
coordinateType=projectedAreaDiameter,
allCoordinates=yes,
normalise=yes,
logTransform=yes
)
fvModel:
cylinderHeat
{
type heatSource;
select all;
q 5e7;
}
fvConstraint:
momentumForce
{
type meanVelocityForce;
select all;
Ubar (0.1335 0 0);
}
particleFoam has been superseded and replaced by the more general functions
solver module executed by the foamRun application:
foamRun -solver functions
The incompressibleFluid solver specified by either the subSolver or if not
present the solver entry in the controlDict is instantiated to provide the
physical fields needed by fvModel functionObject in which the clouds fvModel is
selected to evolve the Lagrangian particles. See:
tutorials/modules/incompressibleFluid/hopperParticles
tutorials/modules/incompressibleFluid/mixerVessel2DParticles
rhoParticleFoam has been superseded and replaced by the more general functions
solver module executed by the foamRun application:
foamRun -solver functions
The isothermalFluid solver specified by either the subSolver or if not present
the solver entry in the controlDict is instantiated to provide the physical
fields needed by fvModel functionObject in which the clouds fvModel is selected
to evolve the Lagrangian particles.
Description
Solver module to execute the \c functionObjects for a specified solver
The solver specified by either the \c subSolver or if not present the \c
solver entry in the \c controlDict is instantiated to provide the physical
fields needed by the \c functionObjects. The \c functionObjects are then
instantiated from the specifications are read from the \c functions entry in
the \c controlDict and executed in a time-loop also controlled by entries in
\c controlDict and the \c maxDeltaT() returned by the sub-solver.
The fields and other objects registered by the sub-solver are set to
NO_WRITE as they are not changed by the execution of the functionObjects and
should not be written out each write-time. Fields and other objects created
and changed by the execution of the functionObjects are written out.
solvers::functions in conjunction with the scalarTransport functionObject
replaces scalarTransportFoam and provide more general handling of the scalar
diffusivity.
executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations. Replaces rhoCentralFoam and all the corresponding
tutorials have been updated and moved to tutorials/modules/shockFluid.
Unlike rhoCentralFoam shockFluid supports mesh refinement/unrefinement, topology
change, run-time mesh-to-mesh mapping, load-balancing in addition to general
mesh-motion.
The tutorials/modules/shockFluid/movingCone case has been updated to demonstrate
run-time mesh-to-mesh mapping mesh topology change based on the
tutorials/modules/incompressibleFluid/movingCone. shockFluid s
Description
Solver module for density-based solution of compressible flow
Based on central-upwind schemes of Kurganov and Tadmor with support for
mesh-motion and topology change.
Reference:
\verbatim
Greenshields, C. J., Weller, H. G., Gasparini, L.,
& Reese, J. M. (2010).
Implementation of semi‐discrete, non‐staggered central schemes
in a colocated, polyhedral, finite volume framework,
for high‐speed viscous flows.
International journal for numerical methods in fluids, 63(1), 1-21.
\endverbatim
SourceFiles
shockFluid.C
See also
Foam::solvers::fluidSolver
Foam::solvers::incompressibleFluid
executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations. Replaces compressibleMultiphaseInterFoam and all the
corresponding tutorials have been updated and moved to
tutorials/modules/compressibleMultiphaseVoF.
compressibleMultiphaseVoF is derived from the multiphaseVoFSolver which adds
compressible multiphase capability to the VoFSolver base-class used as the basis
of all two-phase and multiphase VoF solvers.
Class
Foam::solvers::compressibleMultiphaseVoF
Description
Solver module for the solution of multiple compressible, 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.
A mixture approach for momentum transport is provided in which a single
laminar, RAS or LES model is selected to model the momentum stress.
Uses the flexible PIMPLE (PISO-SIMPLE) solution for time-resolved and
pseudo-transient and steady simulations.
SourceFiles
compressibleMultiphaseVoF.C
See also
Foam::solvers::VoFSolver
Foam::solvers::multiphaseVoFSolver
executed with foamRun for single region simulations of foamMultiRun for
multi-region simulations. Replaces multiphaseInterFoam and all the
corresponding tutorials have been updated and moved to
tutorials/modules/incompressibleMultiphaseVoF.
incompressibleMultiphaseVoF is derived from the multiphaseVoFSolver which adds
multiphase capability to the VoFSolver base-class used as the basis of all
two-phase and multiphase VoF solvers.
Class
Foam::solvers::incompressibleMultiphaseVoF
Description
Solver module for the solution of multiple 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.
A mixture approach for momentum transport is provided in which a single
laminar, RAS or LES model is selected to model the momentum stress.
Uses the flexible PIMPLE (PISO-SIMPLE) solution for time-resolved and
pseudo-transient and steady simulations.
SourceFiles
incompressibleMultiphaseVoF.C
See also
Foam::solvers::VoFSolver
Foam::solvers::multiphaseVoFSolver
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
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
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
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;
}
...
}
so that it can now be used with either the isothermalFluid or fluid solver
modules, thus supporting non-uniform fluid properties, compressibility and
thermal effect. This development makes the special potentialFreeSurfaceFoam
solver redundant as both the isothermalFluid and fluid solver modules are more
general and has been removed and replaced with a user redirection script.
The tutorials/multiphase/potentialFreeSurfaceFoam cases have been updated to run
with the isothermalFluid solver module:
tutorials/multiphase/potentialFreeSurfaceFoam/oscillatingBox
tutorials/multiphase/potentialFreeSurfaceFoam/movingOscillatingBox
which demonstrate how to upgrade potentialFreeSurfaceFoam cases to
isothermalFluid.
