The volumeFractionSource represents the effect of a reduction in the
volume of the domain due to the presence of a stationary phase, most
likely a solid porous media. It only represents the dynamic effects
associated with the reduction in volume; it does not does not model
loss, drag or heat transfer. Separate models (e.g., the existing
porosity models) will be necessary to represent these effects. An
example usage, in system/fvOptions, is as follows:
volumeFraction
{
type volumeFractionSource;
phase solid;
phi phi;
rho rho;
U U;
fields (rho U e);
}
The volume fraction will be read from constant/alpha.<phase>, and must
be generated in advance using setFields or a function object. Note that
the names of the flux, density (if compressible) and velocity must all
be specified. Every field for which a transport equation is solved
should also be specified in the "fields" entry.
The solidEquilibriumEnergySource adds the thermal inertia and diffusive
characteristics of a stationary solid phase to the energy equation of
the fluid, assuming that the two phases are in thermal equilibrium. An
example usage is as follows:
solidEqulibriumEnergy
{
type solidEqulibriumEnergySource;
phase solid;
field e;
}
This will read the volume fraction in the same way as the
volumeFractionSource option. In addition, thermal properties of the
solid will be constructed from settings in
system/thermophysicalProperties.<phase>.
Two tutorials have been added, demonstrating use of these options in
both incompressible and compressible simulations. These are
incompressible/pimpleFoam/laminar/blockedChannel and
compressible/rhoPimpleFoam/laminar/blockedChannel.
Implementation of the Giesekus model for visco-elasticity, derived from the new
generalised form of the Maxwell model which now support additional sources.
Giesekus, H., 1982.
A simple constitutive equation for polymer fluids based on the
concept of deformation-dependent tensional mobility.
J. Non-Newton. Fluid. 11, 69–109.
This implementation is instantiated for incompressible, compressible and VoF
two-phase flow.
For most steady cases simpleFoam is likely to converge faster than pimpleFoam
with LTS but this capability may be useful for testing meshes, BCs etc. for more
complex solver for which SIMPLE is not stable and LTS is provided instead.
With the selection of the Boussinesq equation of state the general buoyancy
solvers buoyantSimpleFoam and buoyantPimpleFoam can be used instead of the
specialised Boussinesq solvers avoiding the need for special implementation of
thermal and pressure boundary conditions and providing support for radiation and
fvOptions which would not have been feasible or practical in the Boussinesq
solvers.
Other incompressible equations of state are also supported; for most gaseous
problems the incompressiblePerfectGas equation of state is likely to be more
accurate than the Boussinesq equation of state.
The buoyantBoussinesq[SP]impleFoam tutorials have been updated and moved to the
corresponding buoyant[SP]impleFoam directories.
The dense drag models (WenYu, ErgunWenYu and PlessisMasliyah) have been
extended so that they can create their own void-fraction field when one
is not otherwise available.
The duplicated functionality in the drag models has been generalised and
is now utilised by multiple models.
References have been added for all models for which they could be found.
In addition, an additional drag model, SchillerNaumann, has been added.
This is of the same form as sphereDrag, and is designed for the same
scenario; sparsely distributed spherical particles. The SchillerNaumann
form is more widely referenced and should now be considered standard.
The thermo-parcel-specific force instantiation macro has been removed,
as all the force models are now possible to use with all parcel types.
Resolves bug report https://bugs.openfoam.org/view.php?id=3191
The writeEntry form is now defined and used consistently throughout OpenFOAM
making it easier to use and extend, particularly to support binary IO of complex
dictionary entries.
The radiation modelling library has been moved out of
thermophysicalProperties into the top-level source directory. Radiation
is a process, not a property, and belongs alongside turbulence,
combustion, etc...
The namespaces used within the radiation library have been made
consistent with the rest of the code. Selectable sub-models are in
namespaces named after their base classes. Some models have been
renamed remove the base type from the suffix, as this is unnecessary.
These renames are:
Old name: New name:
binaryAbsorptionEmission binary
cloudAbsorptionEmission cloud
constantAbsorptionEmission constant
greyMeanAbsorptionEmission greyMean/greyMeanCombustion
greyMeanSolidAbsorptionEmission greyMeanSolid
wideBandAbsorptionEmission wideBand/wideBandCombustion
cloudScatter cloud
constantScatter constant
mixtureFractionSoot mixtureFraction
Some absorption-emission models have been split into versions which do
and don't use the heat release rate. The version that does has been
given the post-fix "Combustion" and has been moved into the
combustionModels library. This removes the dependence on a registered
Qdot field, and makes the models compatible with the recent removal of
that field from the combustion solvers.
This tutorial serves as a reference of how to create a multi-region
mesh with layer addition.
The multiRegionHeater tutorial and it's variants have been removed as
the geometry is not meaningful and the functionality is now all
represented elsewhere.
This allows coefficients of the constantAbsorptionEmission and
constantScatter to be entered as pure numbers, with the name and
dimensions set automatically, rather than having to specify them
manually.
The keyword which selects how the subset over which the function
operates is generated has been renamed to "selectionMode", to make it
more consistent with other parts of the OpenFOAM (e.g., fvOptions). It
can still take the value "all" or "cellZone". A cell zone is now
specified with a "cellZone", again for consistency.
Error messaging has also been overhauled.
Patch contributed by Institute of Fluid Dynamics,
Helmholtz-Zentrum Dresden - Rossendorf (HZDR)
A number of improvements have been made to the population balance phase
change drift model.
- The model now checks the ordering of the phase pairs and changes the
sign of the drift rate accordingly.
- The phase change mass flux and weights are calculated for each
velocity group, so the drift rate and phase change mass flux should be
consistent for each velocity group.
- By default the phase change mass flux is distributed between the size
groups based on the interfacial area of each group. For backward
compatibility number weighting can be enabled with a new
"numberWeighted" option.
The model now requires the user to provide a list of phase pairs in the
usual parenthesised form, rather than using the name. For example:
phaseChange
{
pairs ((gas and liquid));
}
Patch contributed by Juho Peltola, VTT.
The Qdot field has been removed from all reacting solvers, in favour of
computing on the fly whenever it is needed. It can still be generated
for post-processing purposes by means of the Qdot function object. This
change reduces code duplication and storage for all modified solvers.
The Qdot function object has been applied to a number of tutorials in
order to retain the existing output.
A fix to Qdot has also been applied for multi-phase cases.
This function object writes out the heat release rate field for a
combustion model. This is useful for solvers where combustion is
optional, and which do not therefore write out the heat release rate by
default; e.g., chtMultiRegionFoam and reactingTwoPhaseEulerFoam.
The tutorial has been converted from two-dimensions to a wedge and the
flow has been swirl stabilised. The turbulence parameters have been made
physical. The transport schemes have been increased to second order. The
reaction mechanism has been changed to one from a publically accessible
reference. The gas thermodynamics have been made incompressible, and the
pressure offset around zero, which improves the behaviour of the
pressure solution.
Added headers to all reactions files to prevent warnings in paraview.
Added references for known mechanisms. Removed unused reaction and
thermophysical property files.
With the inclusion of boundary layer modelling in the gas, the
separation of wave perturbation from and mean flow became less useful,
and potentially prevents further extension to support similar boundary
layer modelling in the liquid.
The mean velocity entry, UMean, is now needed in the
constant/waveProperties file rather than in the waveVelocity boundary
condition.
In order to increase the flexibility of the wave library, the mean flow
handling has been removed from the waveSuperposition class. This makes
waveSuperposition work purely in terms of perturbations to a mean
background flow.
The input has also been split, with waves now defined as region-wide
settings in constant/waveProperties. The mean flow parameters are sill
defined by the boundary conditions.
The new format of the velocity boundary is much simpler. Only a mean
flow velocity is required.
In 0/U:
boundaryField
{
inlet
{
type waveVelocity;
UMean (2 0 0);
}
// etc ...
}
Other wave boundary conditions have not changed.
The constant/waveProperties file contains the wave model selections and
the settings to define the associated coordinate system and scaling
functions:
In constant/waveProperties:
origin (0 0 0);
direction (1 0 0);
waves
(
Airy
{
length 300;
amplitude 2.5;
phase 0;
angle 0;
}
);
scale table ((1200 1) (1800 0));
crossScale constant 1;
setWaves has been changed to use a system/setWavesDict file rather than
relying on command-line arguments. It also now requires a mean velocity
to be specified in order to prevent ambiguities associated with multiple
inlet patches. An example is shown below:
In system/setWavesDict:
alpha alpha.water;
U U;
liquid true;
UMean (1 0 0);
This is to make it clear that the value supplied is the scalar mean
velocity normal to the patch, and to distinguish it from other instances
of the keyword "UMean" which take a vector quantity.
The Scaled Function1 removes the need for classes to hold both a value
and a ramping function. If it is desired to ramp up a velocity up to
(10 0 0) over the space of 5 seconds, that can be achieved as follows:
velocity
{
type scale;
scale
{
type halfCosineRamp;
duration 5;
}
value (10 0 0);
}
Also, as a result of this change, the velocityRamping fvOption has
become a general acceleration source, based on a velocity Function1. It
has therefore been renamed accelerationSource.
