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
- provides a simple means of defining/modifying fields. For example,
```
<name1>
{
type exprField;
libs (fieldFunctionObjects);
field pTotal;
expression "p + 0.5*(rho*magSqr(U))";
dimensions [ Pa ];
}
```
It is is also possible to modify an existing field.
For example, to modify the previous one.
```
<name2>
{
type exprField;
libs (fieldFunctionObjects);
field pTotal;
action modify;
// Static pressure only in these regions
fieldMask
#{
(mag(pos()) < 0.05) && (pos().y() > 0)
|| cellZone(inlet)
#};
expression "p";
}
```
To use as a simple post-process calculator, simply avoid storing the
result and only generate on write:
```
<name2>
{
store false;
executionControl none;
writeControl writeTime;
...
}
```
- literal lookups only for expression strings
- code reduction for setExprFields.
- changed keyword "condition" to "fieldMask" (option -field-mask).
This is a better description of its purpose and avoids possible
naming ambiguities with functionObject triggers (for example)
if we apply similar syntax elsewhere.
BUG: erroneous check in volumeExpr::parseDriver::isResultType()
- not triggered since this method is not used anywhere
(may remove in future version)
