The distributions have been extended in various ways to permit usage in
a greater variety of situations...
The distributions now have write methods which allow a distribution to
be written into a field file for restart, therby permitting their usage
in boundary conditions and similar. Their read methods now also support
dimension-checked unit conversions for all their parameters.
An additional selector has been added that allows a distribution to be
re-constructed with a different sample size exponent.
The distributions now own their random generator, thereby simplifying
their usage and preventing the need for a (potentially dangling)
reference member. This makes sense now as the random generators do not
rely on global state; individual sub-models can and should own their own
random generator and manage its initialisation and restart. This
principle should be extended to other parts of the code in future.
*** Note that this commit depends on a corresponding change in
ThirdParty-dev. Ensure that both repositories are up to date before
re-building OpenFOAM.
New environment variables have been added to explicitly control the
installation type of the thirdparty decomposition libraries and of the
ParaView visualiation software. These are set in the etc/bashrc and can
be overridden in a ~/.OpenFOAM/<version>/prefs.sh file or similar.
The variables relating to the decomposition libraries are SCOTCH_TYPE,
METIS_TYPE, PARMETIS_TYPE and ZOLTAN_TYPE, and they can take values of
none, system, or ThirdParty. In the case of ThirdParty, a
<library>_VERSION variable can also be specified. If the version is not
specified then the configuration will search for a source directory, and
if multiple such directories are found then the one with the highest
version number will be used.
The variable relating to ParaView is ParaView_TYPE, and this can be
similarly be set to none, system, or ThirdParty, and ParaView_VERSION
can also be specified when the type is ThirdParty. If the version is not
specified then the installation with the highest version number will be
used.
An example ~/.OpenFOAM/dev/prefs.sh file, in which all decomposition
libraries are enabled, and the Scotch and ParaView versions are
explicitly set, is as follows:
export SCOTCH_TYPE=ThirdParty
export SCOTCH_VERSION=7.0.3
export METIS_TYPE=ThirdParty
export PARMETIS_TYPE=ThirdParty
export ZOLTAN_TYPE=ThirdParty
export ParaView_TYPE=ThirdParty
export ParaView_VERSION=5.11.2
*** Note that if version numbers are not set then the configuration will
search for a decomposition source directory, but it will search for a
ParaView installation directory. This is because decomposition libraries
are built as part of OpenFOAM's ./Allwmake, but ParaView is not. This
distinction remains. If a local compilation of ParaView is needed, then
'./makeParaView -version X.XX.X' should be called explicitly in the
third party directory prior to building OpenFOAM.
The name of the third party directory can now also be independently set.
This simplifies some packaging processes in that it permits third party
to be located within the OpenFOAM installation directory and therefore
bundled into the same binary package.
The majority of input parameters now support automatic unit conversion.
Units are specified within square brackets, either before or after the
value. Primitive parameters (e.g., scalars, vectors, tensors, ...),
dimensioned types, fields, Function1-s and Function2-s all support unit
conversion in this way.
Unit conversion occurs on input only. OpenFOAM writes out all fields and
parameters in standard units. It is recommended to use '.orig' files in
the 0 directory to preserve user-readable input if those files are being
modified by pre-processing applications (e.g., setFields).
For example, to specify a volumetric flow rate inlet boundary in litres
per second [l/s], rather than metres-cubed per second [m^3/s], in 0/U:
boundaryField
{
inlet
{
type flowRateInletVelocity;
volumetricFlowRate 0.1 [l/s];
value $internalField;
}
...
}
Or, to specify the pressure field in bar, in 0/p:
internalField uniform 1 [bar];
Or, to convert the parameters of an Arrhenius reaction rate from a
cm-mol-kcal unit system, in constant/chemistryProperties:
reactions
{
methaneReaction
{
type irreversibleArrhenius;
reaction "CH4^0.2 + 2O2^1.3 = CO2 + 2H2O";
A 6.7e12 [(mol/cm^3)^-0.5/s];
beta 0;
Ea 48.4 [kcal/mol];
}
}
Or, to define a time-varying outlet pressure using a CSV file in which
the pressure column is in mega-pascals [MPa], in 0/p:
boundaryField
{
outlet
{
type uniformFixedValue;
value
{
type table;
format csv;
nHeaderLine 1;
units ([s] [MPa]); // <-- new units entry
columns (0 1);
mergeSeparators no;
file "data/pressure.csv";
outOfBounds clamp;
interpolationScheme linear;
}
}
...
}
(Note also that a new 'columns' entry replaces the old 'refColumn' and
'componentColumns'. This is is considered to be more intuitive, and has
a consistent syntax with the new 'units' entry. 'columns' and
'componentColumns' have been retained for backwards compatibility and
will continue to work for the time being.)
Unit definitions can be added in the global or case controlDict files.
See UnitConversions in $WM_PROJECT_DIR/etc/controlDict for examples.
Currently available units include:
Standard: kg m s K kmol A Cd
Derived: Hz N Pa J W g um mm cm km l ml us ms min hr mol
rpm bar atm kPa MPa cal kcal cSt cP % rad rot deg
A user-time unit is also provided if user-time is in operation. This
allows it to be specified locally whether a parameter relates to
real-time or to user-time. For example, to define a mass source that
ramps up from a given engine-time (in crank-angle-degrees [CAD]) over a
duration in real-time, in constant/fvModels:
massSource1
{
type massSource;
points ((1 2 3));
massFlowRate
{
type scale;
scale linearRamp;
start 20 [CAD];
duration 50 [ms];
value 0.1 [g/s];
}
}
Specified units will be checked against the parameter's dimensions where
possible, and an error generated if they are not consistent. For the
dimensions to be available for this check, the code requires
modification, and work propagating this change across OpenFOAM is
ongoing. Unit conversions are still possible without these changes, but
the validity of such conversions will not be checked.
Units are no longer permitted in 'dimensions' entries in field files.
These 'dimensions' entries can now, instead, take the names of
dimensions. The names of the available dimensions are:
Standard: mass length time temperature
moles current luminousIntensity
Derived: area volume rate velocity momentum acceleration density
force energy power pressure kinematicPressure
compressibility gasConstant specificHeatCapacity
kinematicViscosity dynamicViscosity thermalConductivity
volumetricFlux massFlux
So, for example, a 0/epsilon file might specify the dimensions as
follows:
dimensions [energy/mass/time];
And a 0/alphat file might have:
dimensions [thermalConductivity/specificHeatCapacity];
*** Development Notes ***
A unit conversion can construct trivially from a dimension set,
resulting in a "standard" unit with a conversion factor of one. This
means the functions which perform unit conversion on read can be
provided dimension sets or unit conversion objects interchangeably.
A basic `dict.lookup<vector>("Umean")` call will do unit conversion, but
it does not know the parameter's dimensions, so it cannot check the
validity of the supplied units. A corresponding lookup function has been
added in which the dimensions or units can be provided; in this case the
corresponding call would be `dict.lookup<vector>("Umean", dimVelocity)`.
This function enables additional checking and should be used wherever
possible.
Function1-s and Function2-s have had their constructors and selectors
changed so that dimensions/units must be specified by calling code. In
the case of Function1, two unit arguments must be given; one for the
x-axis and one for the value-axis. For Function2-s, three must be
provided.
In some cases, it is desirable (or at least established practice), that
a given non-standard unit be used in the absence of specific
user-defined units. Commonly this includes reading angles in degrees
(rather than radians) and reading times in user-time (rather than
real-time). The primitive lookup functions and Function1 and Function2
selectors both support specifying a non-standard default unit. For
example, `theta_ = dict.lookup<scalar>("theta", unitDegrees)` will read
an angle in degrees by default. If this is done within a model which
also supports writing then the write call must be modified accordingly
so that the data is also written out in degrees. Overloads of writeEntry
have been created for this purpose. In this case, the angle theta should
be written out with `writeEntry(os, "theta", unitDegrees, theta_)`.
Function1-s and Function2-s behave similarly, but with greater numbers
of dimensions/units arguments as before.
The non-standard user-time unit can be accessed by a `userUnits()`
method that has been added to Time. Use of this user-time unit in the
construction of Function1-s should prevent the need for explicit
user-time conversion in boundary conditions and sub-models and similar.
Some models might contain non-typed stream-based lookups of the form
`dict.lookup("p0") >> p0_` (e.g., in a re-read method), or
`Umean_(dict.lookup("Umean"))` (e.g., in an initialiser list). These
calls cannot facilitate unit conversion and are therefore discouraged.
They should be replaced with
`p0_ = dict.lookup<scalar>("p0", dimPressure)` and
`Umean_(dict.lookup<vector>("Umean", dimVelocity))` and similar whenever
they are found.
Now the HashTable underlying PtrListDictionary is used for zone lookup by name
which is a lot faster than the linear search method used previously if there are
a large number of zones.
The surface mesh setPoints function resets the points without caching the old
points or swept areas so is the equivalent of the polyMesh::setPoints rather
than movePoints.
This provides finer control as to when the changes get constructed and
initial stitching is performed. These is needed by certain processes,
notably decomposition and reconstruction.
By default, the mesh still performs all these operations on a "normal"
read-construction. A flag has to be passed explicitly to the constructor
in order to prevent the post-construction steps.
for consistency with fvModels and fvConstraints, to simplify code and case
maintenance and to avoid the potentially complex functions entries being
unnecessarily parsed by utilities for which functionObject evaluation is
disabled.
The functions entry in controlDict is still read if the functions file is not
present for backward-compatibility, but it is advisable to migrate cases to use
the new functions file.
This lets calling code determine the difference between a polyMesh
topology change and a re-stitch. This prevents unnecessary
post-processing output in a few cases when using NCC; most notably the
generation of cellProc fields by reconstructPar.
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
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.
This new class hierarchy replaces the distributions previously provided
by the Lagrangian library.
All distributions (except fixedValue) now require a "size exponent", Q,
to be specified along with their other coefficients. If a distribution's
CDF(x) (cumulative distribution function) represents what proportion of
the distribution takes a value below x, then Q determines what is meant
by "proportion":
- If Q=0, then "proportion" means the number of sampled values expected
to be below x divided by the total number of sampled values.
- If Q=3, then "proportion" means the expected sum of sampled values
cubed for values below x divided by the total sum of values cubed. If
x is a length, then this can be interpreted as a proportion of the
total volume of sampled objects.
- If Q=2, and x is a length, then the distribution might represent the
proportion of surface area, and so on...
In addition to the user-specification of Q defining what size the given
distribution relates to, an implementation that uses a distribution can
also programmatically define a samplingQ to determine what sort of
sample is being constructed; whether the samples should have an equal
number (sampleQ=0), volume (sampleQ=3), area (sampleQ=2), etc...
A number of fixes to the distributions have been made, including fixing
some fundamental bugs in the returned distribution of samples, incorrect
calculation of the distribution means, renaming misleadingly named
parameters, and correcting some inconsistencies in the way in which
tabulated PDF and CDF data was processed. Distributions no longer
require their parameters to be defined in a sub-dictionary, but a
sub-dictionary is still supported for backwards compatibility.
The distributions can now generate their PDF-s as well as samples, and a
test application has been added (replacing two previous applications),
which thoroughly checks consistency between the PDF and the samples for
a variety of combinations of values of Q and sampleQ.
Backwards incompatible changes are as follows:
- The standard deviation keyword for the normal (and multi-normal)
distribution is now called 'sigma'. Previously this was 'variance',
which was misleading, as the value is a standard deviation.
- The 'massRosinRammler' distribution has been removed. This
functionality is now provided by the standard 'RosinRammler'
distributon with a Q equal to 0, and a sampleQ of 3.
- The 'general' distribution has been split into separate distributions
based on whether PDF or CDF data is provided. These distributions are
called 'tabulatedDensity' and 'tabulatedCumulative', respectively.
The new option takes a value indicating which cell types should be
written out as polyhedra. The values are as follows:
none: No polyhedral cells are written. Cells which match specific
shapes (hex, pyramid, prism, ...) are written as their
corresponding VTK cell types. Arbitrary polyhedral cells
that do not match a specific shape are decomposed into
tetrahedra.
polyhedra: Only arbitrary polyhedral cells are written as a VTK
polyhedron. Cells that match specific shapes are written as
their corresponding VTK cell types.
all: All cells are written as a VTK polyhedron.
The default is 'none', which retains the previous default behaviour.
#includeModel includes an fvModel configuration file into the fvModels file
#includeConstraint includes an fvModel configuration file into the fvConstraints file
These operate in the same manner as #includeFunc does for functionObjects and
search the etc/caseDicts/fvModels and etc/caseDicts/fvConstraints directories
for configuration files and apply optional argument substitution.
Class
Foam::functionEntries::includeFvModelEntry
Description
Specify a fvModel dictionary file to include, expects the
fvModel name to follow with option arguments (without quotes).
Searches for fvModel dictionary file in user/group/shipped
directories allowing for version-specific and version-independent files
using the following hierarchy:
- \b user settings:
- ~/.OpenFOAM/\<VERSION\>/caseDicts/fvModels
- ~/.OpenFOAM/caseDicts/fvModels
- \b group (site) settings (when $WM_PROJECT_SITE is set):
- $WM_PROJECT_SITE/\<VERSION\>/etc/caseDicts/fvModels
- $WM_PROJECT_SITE/etc/caseDicts/fvModels
- \b group (site) settings (when $WM_PROJECT_SITE is not set):
- $WM_PROJECT_INST_DIR/site/\<VERSION\>/etc/caseDicts/fvModels
- $WM_PROJECT_INST_DIR/site/etc/caseDicts/fvModels
- \b other (shipped) settings:
- $WM_PROJECT_DIR/etc/caseDicts/fvModels
The optional field arguments included in the name are inserted in 'field' or
'fields' entries in the fvModel dictionary and included in the name
of the fvModel entry to avoid conflict.
Examples:
\verbatim
#includeModel clouds
#includeModel surfaceFilms
\endverbatim
Other dictionary entries may also be specified using named arguments.
See also
Foam::includeFvConstraintEntry
Foam::includeFuncEntry
Class
Foam::functionEntries::includeFvConstraintEntry
Description
Specify a fvConstraint dictionary file to include, expects the
fvConstraint name to follow with option arguments (without quotes).
Searches for fvConstraint dictionary file in user/group/shipped
directories allowing for version-specific and version-independent files
using the following hierarchy:
- \b user settings:
- ~/.OpenFOAM/\<VERSION\>/caseDicts/fvConstraints
- ~/.OpenFOAM/caseDicts/fvConstraints
- \b group (site) settings (when $WM_PROJECT_SITE is set):
- $WM_PROJECT_SITE/\<VERSION\>/etc/caseDicts/fvConstraints
- $WM_PROJECT_SITE/etc/caseDicts/fvConstraints
- \b group (site) settings (when $WM_PROJECT_SITE is not set):
- $WM_PROJECT_INST_DIR/site/\<VERSION\>/etc/caseDicts/fvConstraints
- $WM_PROJECT_INST_DIR/site/etc/caseDicts/fvConstraints
- \b other (shipped) settings:
- $WM_PROJECT_DIR/etc/caseDicts/fvConstraints
The optional field arguments included in the name are inserted in 'field' or
'fields' entries in the fvConstraint dictionary and included in the name
of the fvConstraint entry to avoid conflict.
Examples:
\verbatim
#includeConstraint limitPressure(minFactor=0.1, maxFactor=2)
#includeConstraint limitTemperature(min=101, max=1000)
\endverbatim
or for a multiphase case:
\verbatim
#includeConstraint limitLowPressure(min=1e4)
#includeConstraint limitTemperature(phase=steam, min=270, max=2000)
#includeConstraint limitTemperature(phase=water, min=270, max=2000)
\endverbatim
Other dictionary entries may also be specified using named arguments.
See also
Foam::includeFvModelEntry
Foam::includeFuncEntry
