Replaced the ad hoc geometric mean blending with the more physical wall distance
Reynolds number blending function.
Additionally the part of the production term active for y+ < 11.6 has been
reinstated.
Partial elimination has been implemented for the multiphase Euler-Euler
solver. This does a linear solution of the drag system when calculating
flux and velocity corrections after the solution of the pressure
equation. This can improve the behaviour of the solution in the event
that the drag coupling is high. It is controlled by means of a
"partialElimination" switch within the PIMPLE control dictionary in
fvSolution.
A re-organisation has also been done in order to remove the exposure of
the sub-modelling from the top-level solver. Rather than looping the
drag, virtual mass, lift, etc..., models directly, the solver now calls
a set of phase-system methods which group the different force terms.
These new methods are documented in MomentumTransferPhaseSystem.H. Many
other accessors have been removed as a consequence of this grouping.
A bug was also fixed whereby the face-based algorithm was not
transferring the momentum associated with a given interfacial mass
transfer.
This change means that getApplication still works if we have a
controlDict.orig, rather than a controlDict. This allows us to simplify
the scripting of tutorials in which the controlDict is modified.
The tutorial demonstrates generation of a C-grid mesh using blockMesh
The geometry is provided by a surface mesh (OBJ file) of the NACA0012 aerofoil
The case is setup with a freestream flow speed of Ma=0.72
Thanks to Kai Bastos at Duke University for the geometry and helpful input.
Some tutorials have had Allrun scripts added in order to run setFields,
which was previously omitted. Others have had nonuniform field files in
the 0 directory replaced by uniform files with .orig extensions.
These BCs blend between typical inflow and outflow conditions based on the
velocity orientation.
airFoil2D tutorial updated to demonstrate these new BCs.
Now if a <field> file does not exist first the compressed <field>.gz file is
searched for and if that also does not exist the <field>.orig file is searched
for.
This simplifies case setup and run scripts as now setField for example can read
the <field>.orig file directly and generate the <field> file from it which is
then read by the solver. Additionally the cleanCase function used by
foamCleanCase and the Allclean scripts automatically removed <field> files if
there is a corresponding <field>.orig file. So now there is no need for the
Allrun scripts to copy <field>.orig files into <field> or for the Allclean
scripts to explicitly remove them.
This is a CHT case which uses snappyHexMesh. It is a tutorial, in the
traditional sense, in that it has been designed for training purposes.
It does not rely on changeDictionary, surface utilities, or extensive
scripting.
This work was supported by Colin Moughton, at Strix
Multi-region PIMPLE controls have been applied to the chtMultiRegionFoam
solver, and a transonic option has been implemented.
The new PIMPLE controls let the solver operate SIMPLE mode. The
utilisation of library solution and convergence control functionality
has significantly reduced the amount of code in the solver. The
chtMultiRegionSimpleFoam solver has also been made obsolete, and has
therefore been removed.
A few changes will be necessary to convert an existing
chtMultiRegionSimpleFoam case to chtMultiRegionFoam. All the SIMPLE
sub-dictionaries in the system/<regions>/fvSolution will need to be
renamed PIMPLE. The system/fvSolution file will also need an empty
PIMPLE sub-dictionary. In addition, additional "<variable>Final" solver
and relaxation entries will be needed. For a steady case, adding a
wildcard ending, ".*", to the variable names should be sufficient.
Solution parameters appropriate for a steady case are shown below:
solvers
{
"p_rgh.*"
{
solver GAMG;
tolerance 1e-7;
relTol 0.01;
smoother DIC;
maxIter 10;
}
"(U|h|e|k|epsilon).*"
{
solver PBiCGStab;
preconditioner DILU;
tolerance 1e-7;
relTol 0.1;
}
}
PIMPLE
{
// ...
}
relaxationFactors
{
fields
{
"p_rgh.*" 0.7;
}
equations
{
"U.*" 0.5;
"(h|e).*" 0.3;
"(k|epsilon).*" 0.2;
}
}
This work was supported by Fabian Buelow, at Evonik
Tobias Holzmann provided cases for testing the convergence controls
The solution controls have been rewritten for use in multi-region
solvers, and PIMPLE fluid/solid solution controls have been implemented
within this framework.
PIMPLE also now has time-loop convergence control which can be used to
end the simulation once a certain initial residual is reached. This
allows a PIMPLE solver to run with equivalent convergence control to a
SIMPLE solver. Corrector loop convergence control is still available,
and can be used at the same time as the time-loop control.
The "residualControl" sub-dictionary of PIMPLE contains the residual
values required on the first solve of a time-step for the simulation to
end. This behaviour is the same as SIMPLE. The
"outerCorrectorResidualControl" sub-dictionary contains the tolerances
required for the corrector loop to exit. An example specification with
both types of control active is shown below.
PIMPLE
{
// ...
residualControl
{
p 1e-3;
U 1e-4;
"(k|epsilon|omega)" 1e-3;
}
outerCorrectorResidualControl
{
U
{
tolerance 1e-4;
relTol 0.1;
}
"(k|epsilon|omega)"
{
tolerance 1e-3;
relTol 0.1;
}
}
}
Note that existing PIMPLE "residualControl" entries will need to be
renamed "outerCorrectorResidualControl".
Application within a solver has also changed slightly. In order to have
convergence control for the time loop as a whole, the
solutionControl::loop(Time&) method (or the equivalent run method) must
be used; i.e.,
while (simple.loop(runTime))
{
Info<< "Time = " << runTime.timeName() << nl << endl;
// solve ...
}
or,
while (pimple.run(runTime))
{
// pre-time-increment operations ...
runTime ++;
Info<< "Time = " << runTime.timeName() << nl << endl;
// solve ...
}
In early versions of OpenFOAM the scalar limits were simple macro replacements and the
names were capitalized to indicate this. The scalar limits are now static
constants which is a huge improvement on the use of macros and for consistency
the names have been changed to camel-case to indicate this and improve
readability of the code:
GREAT -> great
ROOTGREAT -> rootGreat
VGREAT -> vGreat
ROOTVGREAT -> rootVGreat
SMALL -> small
ROOTSMALL -> rootSmall
VSMALL -> vSmall
ROOTVSMALL -> rootVSmall
The original capitalized are still currently supported but their use is
deprecated.
Introduced thermalPhaseChangePopulationBalanceTwo- and MultiphaseSystem as
user-selectable phaseSystems which are the first to actually use multiple mass
transfer mechanisms enabled by
commit d3a237f560.
The functionality is demonstrated using the reactingTwoPhaseEulerFoam
wallBoilingPolydisperse tutorial.
Patch contributed by VTT Technical Research Centre of Finland Ltd and Institute
of Fluid Dynamics, Helmholtz-Zentrum Dresden - Rossendorf (HZDR).
The onset of vertical damping can now be graduated over a distance. The
user specifies an origin and a direction along which the graduation
occurs, and a ramping function to specify the form of the graduation. An
example specification for the fvOption is:
verticalDamping1
{
type verticalDamping;
selectionMode all;
origin (1200 0 0);
direction (1 0 0);
ramp
{
type halfCosineRamp;
start 0;
duration 600;
}
lambda [0 0 -1 0 0 0 0] 1; // Damping coefficient
timeStart 0;
duration 1e6;
}
If the origin, direction or ramp entries are omitted then the fvOption
functions as before; applying the damping to the entire volume or the
specified cell set.
This work was supported by Jan Kaufmann and Jan Oberhagemann at DNV GL.
Using the noSlip boundary condition for rotating wall in an MRF region
interferes with post-processing by resetting the wall velocity to 0 rather than
preserving the value set by the MRF zone.
Removed possibility for the user to specify a driftRate in the constantDrift
model which is independent of a fvOptions mass source. The driftRate must be
calculated from/be consistent with the mass source in order to yield a particle
number conserving result.
Made calculation of the over-all Sauter mean diameter of an entire population
balance conditional on more than one velocityGroup being present. This diameter
field is for post-processing purposes only and would be redundant in case of one
velocityGroup being used.
Solution control is extended to allow for solution of the population balance
equation at the last PIMPLE loop only, using an optional switch. This can be
beneficial in terms of simulation time as well as coupling between the
population balance based diameter calculation and the rest of the equation
system.
Patch contributed by Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden - Rossendorf
(HZDR) and VTT Technical Research Centre of Finland Ltd.
This patch enables the reactingEulerFoam solvers to simulate polydisperse flow
situations, i.e. flows where the disperse phase is subject to a size
distribution.
The newly added populationBalanceModel class solves the integro-partial
differential population balance equation (PBE) by means of a class method, also
called discrete or sectional method. This approach is based on discretizing the
PBE over its internal coordinate, the particle volume. This yields a set of
transport equations for the number concentration of particles in classes with a
different representative size. These are coupled through their source-terms and
solved in a segregated manner. The implementation is done in a way, that the
total particle number and mass is preserved for coalescence, breakup and drift
(i.e. isothermal growth or phase change) processes, irrespective of the chosen
discretization over the internal coordinate.
A population balance can be split over multiple velocity (temperature) fields,
using the capability of reactingMultiphaseEulerFoam to solve for n momentum
(energy) equations. To a certain degree, this takes into account the dependency
of heat- and momentum transfer on the disperse phase diameter. It is also possible
to define multiple population balances, e.g. bubbles and droplets simultaneously.
The functionality can be switched on by choosing the appropriate phaseSystem
type, e.g. populationBalanceMultiphaseSystem and the newly added diameterModel
class called velocityGroup. To illustrate the use of the functionality, a
bubbleColumnPolydisperse tutorial was added for reactingTwoPhaseEulerFoam and
reactingMultiphaseEulerFoam.
Furthermore, a reactingEulerFoam-specific functionObject called sizeDistribution
was added to allow post-Processing of the size distribution, e.g. to obtain the
number density function in a specific region.
Patch contributed by Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden - Rossendorf
(HZDR) and VTT Technical Research Centre of Finland Ltd.
- Thermal phase change and wall boiling functionality has been generalized to
support two- and multi- phase simulations.
- Thermal phase change now also allows purePhaseModel, which simplifies case setup.
- The phaseSystem templates have been restructured in preparation of multiple
simultaneous mass transfer mechanisms. For example, combination of thermal phase
and inhomogeneous population balance models.
Patch contributed by VTT Technical Research Centre of Finland Ltd and Institute
of Fluid Dynamics, Helmholtz-Zentrum Dresden - Rossendorf (HZDR).
A pureMixture can now be specified in a reacting solver. This further
enhances compatibility between non-reacting and reacting solvers.
To achieve this, mixtures now have a typeName function of the same form
as the lower thermodyanmic models. In addition, to avoid name clashes,
the reacting thermo make macros have been split into those that create
entries on multiple selection tables, and those that just add to the
reaction thermo table.
The combustion and chemistry model selection has been simplified so
that the user does not have to specify the form of the thermodynamics.
Examples of new combustion and chemistry entries are as follows:
In constant/combustionProperties:
combustionModel PaSR;
combustionModel FSD;
In constant/chemistryProperties:
chemistryType
{
solver ode;
method TDAC;
}
All the angle bracket parts of the model names (e.g.,
<psiThermoCombustion,gasHThermoPhysics>) have been removed as well as
the chemistryThermo entry.
The changes are mostly backward compatible. Only support for the
angle bracket form of chemistry solver names has been removed. Warnings
will print if some of the old entries are used, as the parts relating to
thermodynamics are now ignored.
and replaced interDyMFoam with a script which reports this change.
The interDyMFoam tutorials have been moved into the interFoam directory.
This change is one of a set of developments to merge dynamic mesh functionality
into the standard solvers to improve consistency, usability, flexibility and
maintainability of these solvers.
Henry G. Weller
CFD Direct Ltd.
and replaced rhoPimpleDyMFoam with a script which reports this change.
The rhoPimpleDyMFoam tutorials have been moved into the rhoPimpleFoam directory.
This change is the first of a set of developments to merge dynamic mesh
functionality into the standard solvers to improve consistency, usability,
flexibility and maintainability of these solvers.
Henry G. Weller
CFD Direct Ltd.
and replaced pimpleDyMFoam with a script which reports this change.
The pimpleDyMFoam tutorials have been moved into the pimpleFoam directory.
This change is the first of a set of developments to merge dynamic mesh
functionality into the standard solvers to improve consistency, usability,
flexibility and maintainability of these solvers.
Henry G. Weller
CFD Direct Ltd.
The new momentum stress model selector class
compressibleInterPhaseTransportModel is now used to select between the options:
Description
Transport model selection class for the compressibleInterFoam family of
solvers.
By default the standard mixture transport modelling approach is used in
which a single momentum stress model (laminar, non-Newtonian, LES or RAS) is
constructed for the mixture. However if the \c simulationType in
constant/turbulenceProperties is set to \c twoPhaseTransport the alternative
Euler-Euler two-phase transport modelling approach is used in which separate
stress models (laminar, non-Newtonian, LES or RAS) are instantiated for each
of the two phases allowing for different modeling for the phases.
Mixture and two-phase momentum stress modelling is now supported in
compressibleInterFoam, compressibleInterDyMFoam and compressibleInterFilmFoam.
The prototype compressibleInterPhaseTransportFoam solver is no longer needed and
has been removed.
