- While a rectilinear mesh can be created with blockMesh, not every mesh
created with blockMesh will satisfy the requirements for being a
rectilinear mesh.
This alternative to blockMesh uses a single block that is aligned
with the xy-z directions and specifications of the control points,
mesh divisions and expansion ratios. For example,
x
{
points ( -13.28 -0.10 6.0 19.19 );
nCells ( 10 12 10 );
ratios ( 0.2 1 5 );
}
y { ... }
z { ... }
With only one block, the boundary patch definition is simple and the
canonical face number is used directly. For example,
inlet
{
type patch;
faces ( 0 );
}
outlet
{
type patch;
faces ( 1 );
}
sides
{
type patch;
faces ( 2 3 );
}
...
- After a mesh is defined, it is trivial to retrieve mesh-related
information such as cell-volume, cell-centres for any i-j-k location
without an actual polyMesh.
STYLE: remove -noFunctionObjects from blockMesh
- no time loop, so function objects cannot be triggered anyhow.
- A negative expansion ratio is geometrically invalid and will
normally cause issues (FatalError).
However, we can trap this type of input and interpret it as the
inverse expansion ratio - ie, the expansion ratio in the opposite
direction. This can be especially convenient when generating a blockMesh
with a symmetrical expansion. It permits using the same expansion
ratio (with a sign change) instead of providing the reciprocal values
manually.
COMP: revert demand-driven point creation in blockMesh (db9b35b50d)
- appears to have caused a dangling reference on some systems
ENH: add a lightweight ijkAddressing class
- it can be used for an i-j-k to linear lookup of meshes or fields,
where applicable.
- avoid potential ambiguities in naming of mesh faces/edges
vs. block faces/edges
- additional methods characterizing the number of faces
(internal, boundary, total) associated with a blockDescriptor
- cellLabel() accessor and checkIndex() methods
- restore demand-driven behaviour of block, cache the calculated cells
and refactor generation of block boundary faces to improve potential
reuse.
- Can result in inadvertent conversions where the user should really
know or check if the pointer is valid prior to using.
- Still have several places to fix that are using the deprecated copy
construct and copy assignment
- changed the sectorCoeffs keyword to 'point' from 'axisPt'
for more similarity with other dictionaries.
Continue to accept 'axisPt' for compatibility.
- makes the intent clearer and avoids the need for additional
constructor casting. Eg,
labelList(10, Zero) vs. labelList(10, 0)
scalarField(10, Zero) vs. scalarField(10, scalar(0))
vectorField(10, Zero) vs. vectorField(10, vector::zero)
- now placed under postProcessing/checkMesh and postProcessing/checkAMI,
respectively.
Output files are now also tagged with the id of the patch, in case
there are multiple AMI patches in use.
- now applicable to labelLists.
Note:
in some situations it will be more efficient to use
Foam::identity() directly. Eg,
globalIndex globalCells(mesh.nCells());
...
labelList cellIds
(
identity(globalCells.localSize(), globalCells.localStart())
);
- as part of the cleanup of dictionary access methods (c6520033c9)
made the dictionary class single inheritance from IDLList<entry>.
This eliminates any ambiguities for iterators and allows
for simple use of range-for looping.
Eg,
for (const entry& e : topDict))
{
Info<< "entry:" << e.keyword() << " is dict:" << e.isDict() << nl;
}
vs
forAllConstIter(dictionary, topDict, iter))
{
Info<< "entry:" << iter().keyword()
<< " is dict:" << iter().isDict() << nl;
}
- more dictionary-like methods, enforce keyType::LITERAL for all
lookups to avoid any spurious keyword matching.
- new readEntry, readIfPresent methods
- The get() method replaces the now deprecate lookup() method.
- Deprecate lookupOrFailsafe()
Failsafe behaviour is now an optional parameter for lookupOrDefault,
which makes it easier to tailor behaviour at runtime.
- output of the names is now always flatted without line-breaks.
Thus,
os << flatOutput(someEnumNames.names()) << nl;
os << someEnumNames << nl;
both generate the same output.
- Constructor now uses C-string (const char*) directly instead of
Foam::word in its initializer_list.
- Remove special enum + initializer_list constructor form since
it can create unbounded lookup indices.
- Removd old hasEnum, hasName forms that were provided during initial
transition from NamedEnum.
- Added static_assert on Enum contents to restrict to enum or
integral values. Should not likely be using this class to enumerate
other things since it internally uses an 'int' for its values.
Changed volumeType accordingly to enumerate on its type (enum),
not the class itself.
- use keyType::option enum to consolidate searching options.
These enumeration names should be more intuitive to use
and improve code readability.
Eg, lookupEntry(key, keyType::REGEX);
vs lookupEntry(key, false, true);
or
Eg, lookupEntry(key, keyType::LITERAL_RECURSIVE);
vs lookupEntry(key, true, false);
- new findEntry(), findDict(), findScoped() methods with consolidated
search options for shorter naming and access names more closely
aligned with other components. Behave simliarly to the
methods lookupEntryPtr(), subDictPtr(), lookupScopedEntryPtr(),
respectively. Default search parameters consistent with lookupEntry().
Eg, const entry* e = dict.findEntry(key);
vs const entry* e = dict.lookupEntryPtr(key, false, true);
- added '*' and '->' dereference operators to dictionary searchers.
- use the dictionary 'get' methods instead of readScalar for
additional checking
Unchecked: readScalar(dict.lookup("key"));
Checked: dict.get<scalar>("key");
- In templated classes that also inherit from a dictionary, an additional
'template' keyword will be required. Eg,
this->coeffsDict().template get<scalar>("key");
For this common use case, the predefined getXXX shortcuts may be
useful. Eg,
this->coeffsDict().getScalar("key");
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.
- this provides internal consistency and allows direct use of the
coordinate angle with sin(), cos() functions.
It eliminates potential issues that could otherwise arise from
alternative user input.
Eg, in mixerFvMesh it would have previously been possible to specify
the coordinate system to use degrees or radians, but these units were
not checked when determining the tangential sweep positions.
NOTE: this may represent a breaking change if user coding has been
relying on cylindrical coordinate system in degrees.
- instead of dict.lookup(name) >> val;
can use dict.readEntry(name, val);
for checking of input token sizes.
This helps catch certain types of input errors:
{
key1 ; // <- Missing value
key2 1234 // <- Missing ';' terminator
key3 val;
}
STYLE: readIfPresent() instead of 'if found ...' in a few more places.
- nBoundaryFaces() is often used and is identical to
(nFaces() - nInternalFaces()).
- forward the mesh nInternalFaces() and nBoundaryFaces() to
polyBoundaryMesh as nFaces() and start() respectively,
for use when operating on a polyBoundaryMesh.
STYLE:
- use identity() function with starting offset when creating boundary maps.
labelList map
(
identity(mesh.nBoundaryFaces(), mesh.nInternalFaces())
);
vs.
labelList map(mesh.nBoundaryFaces());
forAll(map, i)
{
map[i] = mesh.nInternalFaces() + i;
}
