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.
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 $internalField;
}
\endverbatim
See also
Foam::mixedFvPatchScalarField
Foam::Function1
This provides a smooth solution but it is not clear if this is more accurate
than running the cellMomentum p-U algorithm which generates complex transients
in the solution.
Lagrangian's dependency set is simpler than it used to be. There is no
longer a need to maintain a separate library for models that depend on
the momentum transport modelling.
Description
Specify an include file for #calc, expects a single string to follow.
For example if functions from transform.H are used in the #calc expression
\verbatim
angleOfAttack 5; // degs
angle #calc "-degToRad($angleOfAttack)";
#calcInclude "transform.H"
liftDir #calc "transform(Ry($angle), vector(0, 0, 1))";
dragDir #calc "transform(Ry($angle), vector(1, 0, 0))";
\endverbatim
The usual expansion of environment variables and other constructs
(eg, the \c ~OpenFOAM/ expansion) is retained.
See also:
Class
Foam::functionEntries::calcEntry
Description
Uses dynamic compilation to provide calculating functionality
for entering dictionary entries.
E.g.
\verbatim
a 1.0;
b 3;
c #calc "$a*$b";
\endverbatim
Note the explicit trailing 0 ('1.0') to force a to be read (and written)
as a floating point number.
Special care is required for calc entries that include a division since
"/" is also used as the scoping operator to identify keywords in
sub-dictionaries. For example, "$a/b" expects a keyword "b" within a
sub-dictionary named "a". A division can be correctly executed by using a
space between a variables and "/", e.g.
\verbatim
c #calc "$a / $b";
\endverbatim
or "()" scoping around the variable, e.g.
\verbatim
c #calc "($a)/$b";
\endverbatim
Additional include files for the #calc code compilation can be specified
using the #calcInclude entry, e.g. if functions from transform.H are used
\verbatim
angleOfAttack 5; // degs
angle #calc "-degToRad($angleOfAttack)";
#calcInclude "transform.H"
liftDir #calc "transform(Ry($angle), vector(0, 0, 1))";
dragDir #calc "transform(Ry($angle), vector(1, 0, 0))";
\endverbatim
Note:
Internally this is just a wrapper around codeStream functionality - the
#calc string is used to construct a dictionary for codeStream.
Simplifications have been made where possible, as permitted by the new
$<type>var syntax. Duplication has been reduced in similar blockMesh
files (e.g., sloshingTank cases). Settings that cannot practically be
changed have been hard-coded (e.g., angle in the mixerVessel2D
blockMeshDict). The rotor2D blockMeshDict has been centralised and
extended to work with an arbitrary number of rotor blades.
This makes the block/edge/face configuration much more similar between
the four different sections of this mesh. It is also useful as it
permits sections to be decativated by commenting them out without
this affecting all the subsequent numbering.
setFormat no longer defaults to the value of graphFormat optionally set in
controlDict and must be set in the functionObject dictionary.
boundaryFoam, financialFoam and pdfPlot still require a graphFormat entry in
controlDict but this is now read directly rather than by Time.
The parcelsPerSecond control can now be specified as a time-varying
function. This provides additional control over the temporal
distribution of injected parcels, which may be advantageous if, for
example, the mass flow rate varies significantly. It also enables
variable flow rates of particulates in cases which have a fixed number
of particles per parcel.
Description
fvMeshTopoChanger which maps the fields to a new mesh or sequence of meshes
which can optionally be mapped to repeatedly for example in multi-cycle
engine cases or cycled through for symmetric forward and reverse motion.
Usage
\table
Property | Description | Required | Default value
libs | Libraries to load | no |
times | List of times for the meshes | yes |
repeat | Repetition period | no |
cycle | Cycle period | no |
begin | Begin time for the meshes | no | Time::beginTime()
timeDelta | Time tolerance used for time -> index | yes |
\endtable
Examples of the mesh-to-mesh mapping for the multi-cycle
tutorials/incompressibleFluid/movingCone case:
\verbatim
topoChanger
{
type meshToMesh;
libs ("libmeshToMeshTopoChanger.so");
times (0.0015 0.003);
cycle #calc "1.0/300.0";
begin 0;
timeDelta 1e-6;
}
\endverbatim
If the libs entry is not provided and the name of the library containing the
functionObject, fvModel or fvConstraint corresponds to the type specified the
corresponding library is automatically loaded, e.g. to apply the
VoFTurbulenceDamping fvModel to an incompressibleVoF simulation the following
will load the libVoFTurbulenceDamping.so library automatically and instantiate
the fvModel:
turbulenceDamping
{
type VoFTurbulenceDamping;
delta 1e-4;
}
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.
which allows lambda to set higher in the cells adjacent to the boundary which is
particularly useful when solving for waves in a domain with no mean-flow and
wave BCs to avoid numerical stability problems where the specified wave flow
reverses into the domain. The alternative is to use symmetry rather than wave
BCs on the side patches which is stable without using lambdaBoundary but there
is modest distortion of the wave profile adjacent to the side patches which does
not propagate into the domain due to the wave forcing.
to demonstrate motion of a floating object due to waves without any mean flow,
generated by the waveForcing fvModel using the waves specification in
constant/waveProperties which is also used for the side boundary conditions.
