Previously the coordinate system functionality was split between
coordinateSystem and coordinateRotation. The coordinateRotation stored
the rotation tensor and handled all tensor transformations.
The functionality has now been revised and consolidated into the
coordinateSystem classes. The sole purpose of coordinateRotation
is now just to provide a selectable mechanism of how to define the
rotation tensor (eg, axis-angle, euler angles, local axes) for user
input, but after providing the appropriate rotation tensor it has
no further influence on the transformations.
--
The coordinateSystem class now contains an origin and a base rotation
tensor directly and various transformation methods.
- The origin represents the "shift" for a local coordinate system.
- The base rotation tensor represents the "tilt" or orientation
of the local coordinate system in general (eg, for mapping
positions), but may require position-dependent tensors when
transforming vectors and tensors.
For some coordinate systems (currently the cylindrical coordinate system),
the rotation tensor required for rotating a vector or tensor is
position-dependent.
The new coordinateSystem and its derivates (cartesian, cylindrical,
indirect) now provide a uniform() method to define if the rotation
tensor is position dependent/independent.
The coordinateSystem transform and invTransform methods are now
available in two-parameter forms for obtaining position-dependent
rotation tensors. Eg,
... = cs.transform(globalPt, someVector);
In some cases it can be useful to use query uniform() to avoid
storage of redundant values.
if (cs.uniform())
{
vector xx = cs.transform(someVector);
}
else
{
List<vector> xx = cs.transform(manyPoints, someVector);
}
Support transform/invTransform for common data types:
(scalar, vector, sphericalTensor, symmTensor, tensor).
====================
Breaking Changes
====================
- These changes to coordinate systems and rotations may represent
a breaking change for existing user coding.
- Relocating the rotation tensor into coordinateSystem itself means
that the coordinate system 'R()' method now returns the rotation
directly instead of the coordinateRotation. The method name 'R()'
was chosen for consistency with other low-level entities (eg,
quaternion).
The following changes will be needed in coding:
Old: tensor rot = cs.R().R();
New: tensor rot = cs.R();
Old: cs.R().transform(...);
New: cs.transform(...);
Accessing the runTime selectable coordinateRotation
has moved to the rotation() method:
Old: Info<< "Rotation input: " << cs.R() << nl;
New: Info<< "Rotation input: " << cs.rotation() << nl;
- Naming consistency changes may also cause code to break.
Old: transformVector()
New: transformPrincipal()
The old method name transformTensor() now simply becomes transform().
====================
New methods
====================
For operations requiring caching of the coordinate rotations, the
'R()' method can be used with multiple input points:
tensorField rots(cs.R(somePoints));
and later
Foam::transformList(rots, someVectors);
The rotation() method can also be used to change the rotation tensor
via a new coordinateRotation definition (issue #879).
The new methods transformPoint/invTransformPoint provide
transformations with an origin offset using Cartesian for both local
and global points. These can be used to determine the local position
based on the origin/rotation without interpreting it as a r-theta-z
value, for example.
================
Input format
================
- Streamline dictionary input requirements
* The default type is cartesian.
* The default rotation type is the commonly used axes rotation
specification (with e1/e2/3), which is assumed if the 'rotation'
sub-dictionary does not exist.
Example,
Compact specification:
coordinateSystem
{
origin (0 0 0);
e2 (0 1 0);
e3 (0.5 0 0.866025);
}
Full specification (also accepts the longer 'coordinateRotation'
sub-dictionary name):
coordinateSystem
{
type cartesian;
origin (0 0 0);
rotation
{
type axes;
e2 (0 1 0);
e3 (0.5 0 0.866025);
}
}
This simplifies the input for many cases.
- Additional rotation specification 'none' (an identity rotation):
coordinateSystem
{
origin (0 0 0);
rotation { type none; }
}
- Additional rotation specification 'axisAngle', which is similar
to the -rotate-angle option for transforming points (issue #660).
For some cases this can be more intuitive.
For example,
rotation
{
type axisAngle;
axis (0 1 0);
angle 30;
}
vs.
rotation
{
type axes;
e2 (0 1 0);
e3 (0.5 0 0.866025);
}
- shorter names (or older longer names) for the coordinate rotation
specification.
euler EulerRotation
starcd STARCDRotation
axes axesRotation
================
Coding Style
================
- use Foam::coordSystem namespace for categories of coordinate systems
(cartesian, cylindrical, indirect). This reduces potential name
clashes and makes a clearer declaration. Eg,
coordSystem::cartesian csys_;
The older names (eg, cartesianCS, etc) remain available via typedefs.
- added coordinateRotations namespace for better organization and
reduce potential name clashes.
- 'signed' input parameter only mandatory for distance > 0.
A distance <= 0 is always signed and the input parameter is ignored.
- Use normal distance when distance == 0. This has no effect when
the surface has no open edges, but improves on rounding issues
around the zero crossing when the surface has open edges.
This may still need future revisiting.
- takes a direct approach of determining which cells are cut and walks
the cell faces directly to build the resulting surface.
- better handling of corner cases.
* Avoids redundant points when the cut passes exactly through a
mesh point.
* Supresses generation of duplicates faces when the plane cut
coincides exactly with a mesh face.
- for severely concave cells where the plane cuts a face multiple times
there is currently no remedial action taken, except to note the
failure and unwind the insertion of the corresponding points and
faces.
- improve doxygen entries for searchable surfaces.
- support selection of searchable surfaces with shorter names.
Eg,
type box | cylinder | ...;
vs type searchableBox | searchableCylinder | ...;
- functionObjectLibs -> libs
- redirectType -> name
- change deprecated writeCompression flags types to Switch.
- cleanup some trailing ';;' from some dictionaries
- some paraview versions (eg, on windows) don't support float, only double.
This mostly affected the vtkSurfaceWriter.
The foamToVTK is also affected, but since it also supports the XML
output formats (vtp, vtu) these can be used instead.
The tutorial demonstrates generation of a C-grid mesh using blockMesh
The geometry is provided by a surface mesh (OBJ file) of the NACA0012 aerofoil
The case is setup with a freestream flow speed of Ma=0.72
Thanks to Kai Bastos at Duke University for the geometry and helpful input.
and replaced rhoPimpleDyMFoam with a script which reports this change.
The rhoPimpleDyMFoam tutorials have been moved into the rhoPimpleFoam directory.
This change is the first of a set of developments to merge dynamic mesh
functionality into the standard solvers to improve consistency, usability,
flexibility and maintainability of these solvers.
Henry G. Weller
CFD Direct Ltd.
rhoReactingFoam: Updated for changes to rhoPimpleFoam files
Now pimpleDyMFoam is exactly equivalent to pimpleFoam when running on a
staticFvMesh. Also when the constant/dynamicMeshDict is not present a
staticFvMesh is automatically constructed so that the pimpleDyMFoam solver can
run any pimpleFoam case without change.
pimpleDyMFoam: Store Uf as an autoPtr for better error handling
pimpleFoam: Set initial deltaT from the Courant number
for improved stability on start-up and compatibility with pimpleDyMFoam
ENH: pimpleFoam: Merged dynamic mesh functionality of pimpleDyMFoam into pimpleFoam
and replaced pimpleDyMFoam with a script which reports this change.
The pimpleDyMFoam tutorials have been moved into the pimpleFoam directory.
This change is the first of a set of developments to merge dynamic mesh
functionality into the standard solvers to improve consistency, usability,
flexibility and maintainability of these solvers.
Henry G. Weller
CFD Direct Ltd.
tutorials/incompressible/pimpleFoam: Updated pimpleDyMFoam tutorials to run pimpleFoam
Renamed tutorials/incompressible/pimpleFoam/RAS/wingMotion/wingMotion2D_pimpleDyMFoam
-> tutorials/incompressible/pimpleFoam/RAS/wingMotion/wingMotion2D_pimpleFoam
- the problem arises since the various surface writers are stateless.
The collated output format hacks around this limitation by adding in
its own fieldDict caching (to disk).
Now include an updateMesh() method to hook into geometry changes.
This is considered a stop-gap measure until the surface output
handling is improved.
- improvement documentation for surface sampling.
- can now specify alternative sampling scheme for obtaining the
face values instead of just using the "cell" value. For example,
sampleScheme cellPoint;
This can be useful for cases when the surface is close to a boundary
cell and there are large gradients in the sampled field.
- distanceSurface now handles non-closed surfaces more robustly.
Unknown regions (not inside or outside) are marked internally and
excluded from consideration. This allows use of 'signed' surfaces
where not previously possible.
Support the following expansions when they occur at the start of a
string:
Short-form Equivalent
========= ===========
<etc>/ ~OpenFOAM/ (as per foamEtcFile)
<case>/ $FOAM_CASE/
<constant>/ $FOAM_CASE/constant/
<system>/ $FOAM_CASE/system/
These can be used in fileName expansions to improve clarity and reduce
some typing
"<constant>/reactions" vs "$FOAM_CASE/constant/reactions"
Within decomposeParDict, it is now possible to specify a different
decomposition method, methods coefficients or number of subdomains
for each region individually.
The top-level numberOfSubdomains remains mandatory, since this
specifies the number of domains for the entire simulation.
The individual regions may use the same number or fewer domains.
Any optional method coefficients can be specified in a general
"coeffs" entry or a method-specific one, eg "metisCoeffs".
For multiLevel, only the method-specific "multiLevelCoeffs" dictionary
is used, and is also mandatory.
----
ENH: shortcut specification for multiLevel.
In addition to the longer dictionary form, it is also possible to
use a shorter notation for multiLevel decomposition when the same
decomposition method applies to each level.
- Arrhenius viscocity model for incompressible viscocity.
- energyTransport FO for incompressible single and multiple phase
flows and viscousDissipation fvOption source.
- Tutorial to show the use of energyTransport:
multiphase/multiphaseInterFoam/laminar/mixerVessel2D
- Tutorial to show viscousDissipation:
compressible/rhoPimpleFoam/RAS/TJunction
- although this has been supported for many years, the tutorials
continued to use "convertToMeters" entry, which is specific to blockMesh.
The "scale" is more consistent with other dictionaries.
ENH:
- ignore "scale 0;" (treat as no scaling) for blockMeshDict,
consistent with use elsewhere.
Solver for low Mach no. flows with adiabatic thermodynamics and updated
pressure-velocity coupling given by the RCM interpolation procedure
described in
\verbatim
Knacke, T. (2013).
Potential effects of Rhie & Chow type interpolations in airframe
noise simulations. In: Schram, C., Dénos, R., Lecomte E. (ed):
Accurate and efficient aeroacoustic prediction approaches for
airframe noise, VKI LS 2013-03.
\endverbatim
Original code supplied by Thilo Knacke, CFD E+F GmbH
contact: info@cfd-berlin.com
Integrated into OpenFOAM by OpenCFD Ltd.
- Use on/off vs longer compressed/uncompressed.
For consistency, replaced yes/no with on/off.
- Avoid the combination of binary/compressed,
which is disallowed and provokes a warning anyhow
