Solution controls now detect when convergence occurs at a write time and
avoid writing the final directory twice. This also resolves the issue
whereby a purgeWrite setting would remove an extra directory.
This resolves bug report https://bugs.openfoam.org/view.php?id=2904
Added a function object for the reacting Euler-Euler solvers which
evaluates and writes out the blended interfacial forces acting on a
given phase (drag, virtual mass, lift, wall lubrication and turbulent
dispersion).
Patch contributed by Institute of Fluid Dynamics, Helmholtz-Zentrum
Dresden - Rossendorf (HZDR)
The Sauter mean diameter calculation has been modified to be more stable
in the limit of vanishing phase fraction. The calculation of the overall
Sauter mean diameter for a populationBalance involving more than one
velocityGroup has been removed. This calculation depends upon the phase
fraction and it is not stable as the fractions tend to zero. The overall
Sauter mean diameter is only used for post-processing and can still be
recovered from the individual diameter fields of the involved
velocityGroups.
Some parts of the population balance modeling have also been renamed and
refactored.
Patch contributed by Institute of Fluid Dynamics, Helmholtz-Zentrum
Dresden - Rossendorf (HZDR)
Surfaces are specified as a list and the controls applied to each, e.g. in the
rhoPimpleFoam/RAS/annularThermalMixer tutorial:
surfaces
(
"AMI.obj"
"shaft.obj"
"wall.obj"
"statorBlades.obj"
"rotorBlades.obj"
);
includedAngle 150; // Identifes a feature when angle
// between faces < includedAngle
trimFeatures
{
minElem 10; // minimum edges within a feature
}
writeObj yes; // writes out _edgeMesh.obj files to view features
If different controls are required for different surfaces multiple
sub-dictionaries can be used:
AMIsurfaces
{
surfaces
(
"AMI.obj"
);
includedAngle 140; // Identifes a feature when angle
// between faces < includedAngle
trimFeatures
{
minElem 8; // minimum edges within a feature
}
writeObj yes; // writes out _edgeMesh.obj files to view features
}
otherSurfaces
{
surfaces
(
"shaft.obj"
"wall.obj"
"statorBlades.obj"
"rotorBlades.obj"
);
includedAngle 150; // Identifes a feature when angle
// between faces < includedAngle
trimFeatures
{
minElem 10; // minimum edges within a feature
}
writeObj yes; // writes out _edgeMesh.obj files to view features
}
Existing feature edge files corresponding to particular surfaces can be specified using
the "files" association list:
surfaces
(
"AMI.obj"
"shaft.obj"
"wall.obj"
"statorBlades.obj"
"rotorBlades.obj"
);
files
(
"AMI.obj" "constant/triSurface/AMI.obj.eMesh";
);
includedAngle 150; // Identifes a feature when angle
// between faces < includedAngle
trimFeatures
{
minElem 10; // minimum edges within a feature
}
writeObj yes; // writes out _edgeMesh.obj files to view features
An "inletOutlet" switch has been added to the wave velocity boundary
condition to allow the boundary to be fixed, as is possible for the
corresponding alpha condition.
A "heightAboveWave" option has been added to the wave superposition
class to calculate velocity based on the height above the wave, rather
than above the origin. This may improve initialisation but it may also
generate divergence in the initial velocity field.
The alpha condition has also been completed so that it applies a
modelled gradient when the flow points out and a wave pressure condition
is in use.
fvcAverage and fvcReconstruct both do divisions or inverses of surface
summed fields. A single-cell zero-dimension case, has no genuine faces
on which to sum, so surface sums are identically zero. This change
detects this situation and returns a zero value instead of failing due
to a divide by zero.
This allows the multiphase test cases to be reduced to just one cell.
to avoid the need for sed'ing the output. This improves performance by avoiding
the need for calling additional commands and generating a temporary file.
The calculations for mixture rho and U have been changed so that they
represent phase-averaged quantities over the moving phases only.
The mixture density is used as part of the pressure solution to
calculate buoyancy forces. The pressure within a stationary phase is
considered to be decoupled from the moving phases; i.e., it is
considered self-supporting. Therefore the stationary phase density
should not form a part of buoyancy calculations. This change to the
definition of mixture density ensures this.
Lookup of models associated with unordered phase pairs now searches for
both possible pair names; e.g. gasAndLiquid and liquidAndGas.
Patch contributed by Institute of Fluid Dynamics, Helmholtz-Zentrum
Dresden - Rossendorf (HZDR)
The nonRandomTwoLiquid and Roult interface composition models have been
instantiated (and updated so that they compile), and a fuller set of
multi-component liquids and multi-component and reacting gases have been
used.
The selection name of the saturated and nonRandomTwoLiquid models have
also been changed to remove the capitalisation from the first letter, as
is consistent with other sub-models that are not proper nouns.
Streamlines can now be tracked in both directions from the set of
initial locations. The keyword controlling this behaviour is
"direction", which can be set to "forward", "backward" or "both".
This new keyword superseeds the "trackForward" entry, which has been
retained for backwards compatibility.
For compatibility with all the mesh and related classes in OpenFOAM The 'normal'
function of the 'triangle', 'triFace' and 'face' classes now returns the unit
normal vector rather than the vector area which is now provided by the 'area'
function.
This model transfers a dispersed droplet phase to a film phase at a rate
relative to its intersection with a third phase. The third phase is
termed the "surface". It can be enabled in constant/phaseProperties as
follows:
phaseTransfer
(
(droplets and film)
{
type deposition;
droplet droplets;
surface solid;
efficiency 0.1;
}
);
The efficiency is an empirical factor which represents a reduction in
collisions as a result of droplets flowing around the surface phase and
not coalescing on impact.
This work was supported by Georg Skillas and Zhen Li, at Evonik
An additional layer has been added into the phase system hierarchy which
facilitates the application of phase transfer modelling. These are
models which exchange mass between phases without the thermal coupling
that would be required to represent phase change. They can be thought of
as representation changes; e.g., between two phases representing
different droplet sizes of the same physical fluid.
To facilitate this, the heat transfer phase systems have been modified
and renamed and now both support mass transfer. The two sided version
is only required for derivations which support phase change.
The following changes to case settings have been made:
- The simplest instantiated phase systems have been renamed to
basicTwoPhaseSystem and basicMultiphaseSystem. The
heatAndMomentumTransfer*System entries in constant/phaseProperties files
will need updating accordingly.
- A phaseTransfer sub-model entry will be required in the
constant/phaseProperties file. This can be an empty list.
- The massTransfer switch in thermal phase change cases has been renamed
phaseTransfer, so as not to be confused with the mass transfer models
used by interface composition cases.
This work was supported by Georg Skillas and Zhen Li, at Evonik
