When the flow is stationary (e.g., at the beginning of a run) the
rDeltaT calculation now requires a maxDeltaT setting in the PIMPLE
sub-section of the fvSolution dictionary. This prevents floating point
errors associated with rDeltaT approaching zero.
The phase velocity mean adjustment was introduced for consistency with phase
flux mean adjustment which is necessary to ensure the mean flux divergence is
preserved. However for systems with very high drag it has proved preferable to
not adjust the velocity of the phases to conserve momentum rather than ensure
consistency with the fluxes.
The old fluid-specific rhoThermo has been split into a non-fluid
specific part which is still called rhoThermo, and a fluid-specific part
called rhoFluidThermo. The rhoThermo interface has been added to the
solidThermo model. This permits models and solvers that access the
density to operate on both solid and fluid thermophysical models.
The he*Thermo classes have been renamed to match their corresponding
basic thermo classes. E.g., rhoThermo now corresponds to RhoThermo,
rather than heRhoThermo.
Mixture classes (e.g., pureMixtrure, coefficientMulticomponentMixture),
now have no fvMesh or volScalarField dependence. They operate on
primitive values only. All the fvMesh-dependent functionality has been
moved into the base thermodynamic classes. The 'composition()' access
function has been removed from multi-component thermo models. Functions
that were once provided by composition base classes such as
basicSpecieMixture and basicCombustionMixture are now implemented
directly in the relevant multi-component thermo base class.
This simplifies the IOerror constructors and allows for the location to
be conveniently cached for errors that can't be triggered until after
the IO operation.
Application
engineCompRatio
Description
Calculate the compression ratio of the engine combustion chamber
If the combustion chamber is not the entire mesh a \c cellSet or
\c cellZone name of the cells in the combustion chamber can be provided.
Usage
\b engineCompRatio [OPTION]
- \par -cellSet \<name\>
Specify the cellSet name of the combustion chamber
- \par -cellZone zoneName
Specify the cellZone name of the combustion chamber
This prevents a crash when decomposing a time-series of topologically
varying meshes. This is not a common or advisable use case, but it is
natural to support it given the combinations of controls that are
available when performing decomposition.
at Function1s of time.
Underlying this new functionObject is a generalisation of the handling of the
maximum time-step in the modular solvers to allow complex user-specification of
the maximum time-step used in a simulation, not just the time-dependency
provided by fluidMaxDeltaT but functions of anything in the simulation by
creating a specialised functionObject in which the maxDeltaT function is
defined.
The chemical and combustion time-scale functionObjects adjustTimeStepToChemistry
and adjustTimeStepToCombustion have been updated and simplified using the above
mechanism.
The deltaTFactor used in the automatic time-step adjustment to smoothly increase
the time-step when permitted can now be specified in the system/controlDict but
defaults to 1.2 as used previously. For example in the
tutorials/incompressibleVoF/damBreak/damBreak case the rate at which the
time-step is increased after the slamming event can be reduced to 10% per
time-step by setting
.
.
.
maxDeltaT 1;
deltaTFactor 1.1;
Alternatively the case can be set to continue with the smallest time-step
without further adjustment by setting deltaTFactor to 1.
and make '-explicitFeatures' the option to use explicitFeatures. When implicitFeatures
is used, a surfaceFeaturesDict file is not written out to the system directory
The following commands are now possible. Note that the '$' sigil on the
FOAM_TUTORIALS environment variable has been escaped with '\' to prevent
it from being expanded to nothing in the outer/interactive shell.
~/OpenFOAM/OpenFOAM-dev/bin/foamExec ls \$FOAM_TUTORIALS/*
~/OpenFOAM/OpenFOAM-dev/bin/foamExec cp -r \$FOAM_TUTORIALS/incompressibleFluid/pitzDaily .
// List of vectors example
listU ((1.1 2.1 1.1) (2.1 3.2 4.1) (4.3 5.3 0));
magU1 #calc "mag($<List<vector>>listU[1])";
// Field of vectors and scalars example
magUs #calc "mag($<Field<vector>>listU)";
magSqrU1 #calc "sqr($<Field<scalar>>magUs[1])";
which calls the fvModel::write function which defaults to doing nothing but can
be overridden in derived fvModels to write useful state information at the end
of the write-times.
Description
Calculates and applies the random OU (Ornstein-Uhlenbeck) process force to
the momentum equation for direct numerical simulation of boxes of isotropic
turbulence.
The energy spectrum is calculated and written at write-times which is
particularly useful to test and compare LES SGS models.
Note
This random OU process force uses a FFT to generate the force field which
is not currently parallelised. Also the mesh the FFT is applied to must
be isotropic and have a power of 2 cells in each direction.
Usage
Example usage:
\verbatim
OUForce
{
type OUForce;
libs ("librandomProcesses.so");
sigma 0.090295;
alpha 0.81532;
kUpper 10;
kLower 7;
}
\endverbatim
The tutorials/incompressibleFluid/boxTurb16 tutorial case is an updated version
of the original tutorials/legacy/incompressible/dnsFoam/boxTurb16 case,
demonstrating the use of the OUForce fvModel with the incompressibleFluid solver
module to replicate the behaviour of the legacy dnsFoam solver application.
for the multiphaseEuler solver module, replacing the more specific
uniformFixedMultiphaseHeatFluxFvPatchScalarField as it provide equivalent
functionality if the heat-flux q is specified.
multiphaseExternalTemperatureFvPatchScalarField is derived from the refactored
and generalised externalTemperatureFvPatchScalarField, overriding the
getKappa member function to provide the multiphase equivalents of kappa and
other heat transfer properties. All controls for
multiphaseExternalTemperatureFvPatchScalarField are the same as for
externalTemperatureFvPatchScalarField:
Class
Foam::externalTemperatureFvPatchScalarField
Description
This boundary condition applies a heat flux condition to temperature
on an external wall. Heat flux can be specified in the following ways:
- Fixed power: requires \c Q
- Fixed heat flux: requires \c q
- Fixed heat transfer coefficient: requires \c h and \c Ta
where:
\vartable
Q | Power Function1 of time [W]
q | Heat flux Function1 of time [W/m^2]
h | Heat transfer coefficient Function1 of time [W/m^2/K]
Ta | Ambient temperature Function1 of time [K]
\endvartable
Only one of \c Q or \c q may be specified, if \c h and \c Ta are also
specified the corresponding heat-flux is added.
If the heat transfer coefficient \c h is specified an optional thin thermal
layer resistances can also be specified through thicknessLayers and
kappaLayers entries.
The patch thermal conductivity \c kappa is obtained from the region
thermophysicalTransportModel so that this boundary condition can be applied
directly to either fluid or solid regions.
Usage
\table
Property | Description | Required | Default value
Q | Power [W] | no |
q | Heat flux [W/m^2] | no |
h | Heat transfer coefficient [W/m^2/K] | no |
Ta | Ambient temperature [K] | if h is given |
thicknessLayers | Layer thicknesses [m] | no |
kappaLayers | Layer thermal conductivities [W/m/K] | no |
relaxation | Relaxation for the wall temperature | no | 1
emissivity | Surface emissivity for radiative flux to ambient | no | 0
qr | Name of the radiative field | no | none
qrRelaxation | Relaxation factor for radiative field | no | 1
\endtable
Example of the boundary condition specification:
\verbatim
<patchName>
{
type externalTemperature;
Ta constant 300.0;
h uniform 10.0;
thicknessLayers (0.1 0.2 0.3 0.4);
kappaLayers (1 2 3 4);
value $internalField;
}
\endverbatim
See also
Foam::mixedFvPatchScalarField
Foam::Function1
