- in continuation of #2565 (rotationCentre for surface output formats)
it is helpful to also support READ_IF_PRESENT behaviour for the
'origin' keyword.
This can be safely used wherever the coordinate system definition
is embedded within a sub-dictionary scope.
Eg,
dict1
{
coordinateSystem
{
origin (0 0 0); // now optional here
rotation ...;
}
}
but remains mandatory if constructed without a sub-dict:
dict2
{
origin (0 0 0); // still mandatory
e1 (1 0 0);
e3 (0 0 1);
}
With this change, the "transform" sub-dictionary can written
more naturally:
formatOptions
{
vtk
{
scale 1000; // m -> mm
transform
{
rotationCentre (1 0 0);
rotation axisAngle;
axis (0 0 1);
angle -45;
}
}
}
ENH: simplify handling of "coordinateSystem" dictionary lookups
- coordinateSystems::NewIfPresent method for optional entries:
coordSysPtr_ = coordinateSystem::NewIfPresent(mesh, dict);
Instead of
if (dict.found(coordinateSystem::typeName, keyType::LITERAL))
{
coordSysPtr_ =
coordinateSystem::New
(
mesh_,
dict,
coordinateSystem::typeName
);
}
else
{
coordSysPtr_.reset();
}
ENH: more consistent handling of priorities for binModels, forces (#2598)
- if the dictionaries are overspecified, give a 'coordinateSystem'
entry a higher prioriy than the 'CofR' shortcuts.
Was previously slightly inconsistent between the different models.
- enables runtime selection of operand coefficients by 'coefficients' entry
- removes binning - now handled using the new 'binField' FO
Co-authored-by: Kutalmis Bercin <kutalmis.bercin@esi-group.com>
- bundles frequently used 'gather/scatter' patterns more consistently.
- combineAllGather -> combineGather + broadcast
- listCombineAllGather -> listCombineGather + broadcast
- mapCombineAllGather -> mapCombineGather + broadcast
- allGatherList -> gatherList + scatterList
- reduce -> gather + broadcast (ie, allreduce)
- The allGatherList currently wraps gatherList/scatterList, but may be
replaced with a different algorithm in the future.
STYLE: PstreamCombineReduceOps.H is mostly unneeded now
Calculates propeller performance and wake field properties.
Controlled by executeControl:
- Propeller performance
- Thrust coefficient, Kt
- Torque coefficient, 10*Kq
- Advance coefficient, J
- Open water efficiency, etaO
- Written to postProcessing/<name>/<time>/propellerPerformance.dat
Controlled by writeControl:
- Wake field text file
- Wake: 1 - UzMean/URef
- Velocity in cylindrical coordinates at xyz locations
- Written to postProcessing/<name>/<time>/wake.dat
- Axial wake field text file
- 1 - Uz/URef at r/R and angle
- Written to postProcessing/<name>/<time>/axialWake.dat
- Velocity surface
- Written to postProcessing/<name>/surfaces/time>/disk.<fileType>
Usage
Example of function object specification:
\verbatim
propellerInfo1
{
type propellerInfo;
libs (forces);
writeControl writeTime;
patches ("propeller.*");
URef 5; // Function1 type; 'constant' form shown here
rho rhoInf; // incompressible
rhoInf 1.2;
// Optionally write propeller performance data
writePropellerPerformance yes;
// Propeller data:
// Radius
radius 0.1;
rotationMode specified; // specified | MRF
// rotationMode = specified:
origin (0 -0.1 0);
n 25.15;
axis (0 1 0);
// Optional reference direction for angle (alpha) = 0
alphaAxis (1 0 0);
//// rotationMode = mrf
//// MRF MRFZoneName;
//// (origin, n and axis retrieved from MRF model)
// Optionally write wake text files
// Note: controlled by writeControl
writeWakeFields yes;
// Sample plane (disk) properties
// Note: controlled by writeControl
sampleDisk
{
surfaceWriter vtk;
r1 0.05;
r2 0.2;
nTheta 36;
nRadial 10;
interpolationScheme cellPoint;
errorOnPointNotFound false;
}
}
\endverbatim
Where the entries comprise:
\table
Property | Description | Required | Deflt value
type | Type name: propellerInfo | yes |
log | Write to standard output | no | no
patches | Patches included in the forces calculation | yes |
p | Pressure field name | no | p
U | Velocity field name | no | U
rho | Density field name | no | rho
URef | Reference velocity | yes |
rotationMode | Rotation mode (see below) | yes |
origin | Sample disk centre | no* |
n | Revolutions per second | no* |
axis | Propeller axis | no* |
alphaAxis | Axis that defines alpha=0 dir | no |
MRF | Name of MRF zone | no* |
originOffset | Origin offset for MRF mode | no | (0 0 0)
writePropellerPerformance| Write propeller performance text file | yes |
writeWakeFields | Write wake field text files | yes |
surfaceWriter | Sample disk surface writer | no* |
r1 | Sample disk inner radius | no | 0
r2 | Sample disk outer radius | no* |
nTheta | Divisions in theta direction | no* |
nRadial | Divisions in radial direction | no* |
interpolationScheme | Sampling interpolation scheme | no* | cell
\endtable
Note
- URef is a scalar Function1 type, i.e. supports constant, table, lookup values
- rotationMode is used to set the origin, axis and revolutions per second
- if set to 'specified' all 3 entries are required
- note: origin is the sample disk origin
- if set to 'MRF' only the MRF entry is required
- to move the sample disk away from the MRF origin, use the originOffset
- if writePropellerPerformance is set to on|true:
- propellerPerformance text file will be written
- if writeWakeFields is set to on|true:
- wake and axialWake text files will be written
- if the surfaceWriter entry is set, the sample disk surface will be written
- extents set according to the r1 and r2 entries
- discretised according to the nTheta and nRadial entries
Previously, for basic incompressible and compressible simulations,
the "force" function object has not been using the user-specified "UName"
for the "devRhoReff" computation (affecting the tangential component),
but using the "U" of the latest available step. In contrast,
the user-specified "pName" has always been being used correctly.
This has been causing issues for users when they wish to use a specific
"UMean" field in various force and forceCoeff function object computations.
- with '&&' conditions, often better to check for non-null autoPtr
first (it is cheap)
- check as bool instead of valid() method for cleaner code, especially
when the wrapped item itself has a valid/empty or good.
Also when handling multiple checks.
Now
if (ptr && ptr->valid())
if (ptr1 || ptr2)
instead
if (ptr.valid() && ptr->valid())
if (ptr1.valid() || ptr2.valid())
- previously introduced `getOrDefault` as a dictionary _get_ method,
now complete the transition and use it everywhere instead of
`lookupOrDefault`. This avoids mixed usage of the two methods that
are identical in behaviour, makes for shorter names, and promotes
the distinction between "lookup" access (ie, return a token stream,
locate and return an entry) and "get" access (ie, the above with
conversion to concrete types such as scalar, label etc).
- additional coefficients:
- Side force coefficient: direction in curl(lift,drag),
- Yaw moment coefficient: rotation axis in dir(lift)
- Roll moment coefficient: rotation axis in dir(drag)
Order of output
- forces(drag,side,lift)
- moments(roll,pitch,yaw)
Note
- For force coeffs, front and rear axles' contributions are computed
- Eg, with surface writers now in surfMesh, there are fewer libraries
depending on conversion and sampling.
COMP: regularize linkage ordering and avoid some implicit linkage (#1238)
- provide a lookupOrDefault constructor form, since this is a fairly
commonly used requirement and simplifies the calling sequence.
Before
dimensionedScalar rhoMax
(
dimensionedScalar::lookupOrDefault
(
"rhoMax",
pimple.dict(),
dimDensity,
GREAT
)
);
After
dimensionedScalar rhoMax("rhoMax", dimDensity, GREAT, pimple.dict());
- read, readIfPresent methods with alternative lookup names.
- Mark the Istream related constructors with compile-time deprecated
warnings.
BUG: read, readIfPresent methods not handling optional dimensions (#1148)
- 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)
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.
- The iterator for a HashSet dereferences directly to its key.
- Eg,
for (const label patchi : patchSet)
{
...
}
vs.
forAllConstIter(labelHashSet, patchSet, iter)
{
const label patchi = iter.key();
...
}
- when constructing dimensioned fields that are to be zero-initialized,
it is preferrable to use a form such as
dimensionedScalar(dims, Zero)
dimensionedVector(dims, Zero)
rather than
dimensionedScalar("0", dims, 0)
dimensionedVector("zero", dims, vector::zero)
This reduces clutter and also avoids any suggestion that the name of
the dimensioned quantity has any influence on the field's name.
An even shorter version is possible. Eg,
dimensionedScalar(dims)
but reduces the clarity of meaning.
- NB: UniformDimensionedField is an exception to these style changes
since it does use the name of the dimensioned type (instead of the
regIOobject).
