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MRF SimpleFoam - Wind Turbine Blade - Underestimating forces |
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October 28, 2021, 12:00
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MRF SimpleFoam - Wind Turbine Blade - Underestimating forces
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#1 |
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New Member
Join Date: Sep 2021
Posts: 6
Rep Power: 4  |
Hello,
I am trying to simulate in a steady flow a 15 MW IEA turbine blade in a 120° axisymmetric wedge domain. The size of the domain is 2 radii in front of the blade, 5 radii behind and 1.5 radii high. There are 2 regions in the mesh: Rotor that moves at -0.76 rad/s, and external wedge (cunha_externa) that is stationary. The moment at x, converged at -1.72E+6Nm. Whereas by the technical parameters approx. -5.7E+6Nm is expected (power coefficient (cp) = 0.489). I don't know what I am doing wrong, with the dynamic mesh method and transient solver I achieved the results. I'm using the simplefoam solver with mrf. The turbulence model is K Omega SST. Definition of iea 15mw: https://www.nrel.gov/docs/fy20osti/75698.pdf Mesh and results: https://drive.google.com/drive/folde...bC?usp=sharing I tried to simulate a in a similar way of the case iv from this article (https://doi.org/10.1016/j.renene.2018.07.062) Boundaries: U Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2106 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format binary;
arch "LSB;label=32;scalar=64";
class volVectorField;
location "0";
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 1 -1 0 0 0 0];
internalField uniform (-10 0 0);
boundaryField
{
pa
{
type noSlip;
}
"(lateral|entrada)"
{
type fixedValue;
value $internalField;
}
saida
{
type zeroGradient;
}
"(lado0|lado120)"
{
type cyclicAMI;
}
"(AMI_1|AMI_2)"
{
type cyclicAMI;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2106 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format binary;
arch "LSB;label=32;scalar=64";
class volScalarField;
location "0";
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 2 -2 0 0 0 0];
internalField uniform 0;
boundaryField
{
"(pa|lateral|entrada)"
{
type zeroGradient;
}
saida
{
type fixedValue;
value $internalField;
}
"(lado0|lado120)"
{
type cyclicAMI;
}
"(AMI_1|AMI_2)"
{
type cyclicAMI;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2106 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format binary;
arch "LSB;label=32;scalar=64";
class volScalarField;
location "0";
object k;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 2 -2 0 0 0 0];
internalField uniform 0.06;
boundaryField
{
pa
{
type kqRWallFunction;
value $internalField;
}
"(entrada|lateral)"
{
type fixedValue;
value $internalField;
}
saida
{
type zeroGradient;
}
"(lado0|lado120)"
{
type cyclicAMI;
}
"(AMI_1|AMI_2)"
{
type cyclicAMI;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2106 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format binary;
arch "LSB;label=32;scalar=64";
class volScalarField;
location "0";
object omega;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 0 -1 0 0 0 0];
internalField uniform 4.5939;
boundaryField
{
pa
{
type omegaWallFunction;
value $internalField;
}
"(entrada|lateral)"
{
type fixedValue;
value $internalField;
}
saida
{
type zeroGradient;
}
"(lado0|lado120)"
{
type cyclicAMI;
}
"(AMI_1|AMI_2)"
{
type cyclicAMI;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2106 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format binary;
arch "LSB;label=32;scalar=64";
class volScalarField;
location "0";
object nut;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 2 -1 0 0 0 0];
internalField uniform 0;
boundaryField
{
pa
{
type nutkWallFunction;
value $internalField;
}
"(entrada|saida|lateral)"
{
type calculated;
value $internalField;
}
"(lado0|lado120)"
{
type cyclicAMI;
}
"(AMI_1|AMI_2)"
{
type cyclicAMI;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2106 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object MRFProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
MRF1
{
cellZone Rotor_zone;
active yes;
// Fixed patches (by default they 'move' with the MRF zone)
nonRotatingPatches (AMI_1 AMI_2);
origin (0 0 0);
axis (1 0 0);
omega 0.769230769231; // rad/s
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 5 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
ddtSchemes
{
default steadyState;
}
gradSchemes
{
default Gauss linear;
}
divSchemes
{
default none;
div(phi,U) bounded Gauss linearUpwind grad(U);
div(phi,omega) Gauss upwind;
div(phi,k) Gauss upwind;
div((nuEff*dev2(T(grad(U))))) Gauss linear;
}
laplacianSchemes
{
default Gauss linear corrected;
}
snGradSchemes
{
default corrected;
}
wallDist
{
method meshWave;
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 5 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
solvers
{
p
{
solver GAMG;
tolerance 1e-7;
relTol 0;
smoother GaussSeidel;
cacheAgglomeration no;
maxIter 500;
}
"(U|k|omega)"
{
solver smoothSolver;
smoother GaussSeidel;
tolerance 1e-7;
relTol 0;
nSweeps 2;
}
}
SIMPLE
{
nNonOrthogonalCorrectors 0;
consistent yes;
pRefCell 0;
pRefValue 0;
residualControl
{
p 1e-6;
"(U|k|omega)" 1e-6;
}
}
relaxationFactors
{
fields
{
p 0.3;
}
equations
{
"(U|k|omega)" 0.7;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 5 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object forcesIncompressible;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
forces
{
functionObjectLibs ("libforces.so");
patches (pa);
CofR (3.770655 0 0);
pitchAxis (0 0 0);
writeControl adjustableRunTime;
writeInterval 1;
type forces;
pName p;
UName U;
rho rhoInf; // Incompressible solver
rhoInf 1.18732;
log true;
}
// ************************************************************************* //
Code:
/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2106 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : _7b82832f-20210625 OPENFOAM=2106
Arch : "LSB;label=32;scalar=64"
Exec : checkMesh
Date : Oct 28 2021
Time : 12:36:07
Host : DESKTOP-H7B8IOF
PID : 510
I/O : uncollated
Case : iea_15mw
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time
Create mesh for time = 0
Time = 0
Mesh stats
points: 15087385
faces: 43973155
internal faces: 43441104
cells: 14447935
faces per cell: 6.050294
boundary patches: 8
point zones: 0
face zones: 0
cell zones: 2
Overall number of cells of each type:
hexahedra: 13867146
prisms: 153181
wedges: 0
pyramids: 0
tet wedges: 129
tetrahedra: 0
polyhedra: 427479
Breakdown of polyhedra by number of faces:
faces number of cells
4 8873
5 7662
6 65466
7 150255
8 20204
9 117862
10 552
11 119
12 50013
13 2
14 19
15 6408
18 44
Checking topology...
Boundary definition OK.
Cell to face addressing OK.
Point usage OK.
Upper triangular ordering OK.
Face vertices OK.
*Number of regions: 2
The mesh has multiple regions which are not connected by any face.
<<Writing region information to "0/cellToRegion"
<<Writing region 0 with 4975517 cells to cellSet region0
<<Writing region 1 with 9472418 cells to cellSet region1
Checking patch topology for multiply connected surfaces...
Patch Faces Points Surface topology
entrada 8482 8557 ok (non-closed singly connected)
saida 8482 8557 ok (non-closed singly connected)
lado0 46631 48006 ok (non-closed singly connected)
lado120 46736 48116 ok (non-closed singly connected)
lateral 68880 69465 ok (non-closed singly connected)
pa 274482 283476 ok (non-closed singly connected)
AMI_2 39182 39181 ok (non-closed singly connected)
AMI_1 39176 39405 ok (non-closed singly connected)
Checking faceZone topology for multiply connected surfaces...
No faceZones found.
Checking basic cellZone addressing...
CellZone Cells Points VolumeBoundingBox
cunha_externa 4975517 5070077 2.821492e+07 (-600 -155.8846 -3.64628e-16) (240 155.8846 180)
Rotor_zone 9472418 10017308 282470.2 (-4.006414 -112.5832 -1.408003e-05) (12.00412 112.5835 130)
Checking geometry...
Overall domain bounding box (-600 -155.8846 -1.408003e-05) (240 155.8846 180)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (2.330773e-17 7.088203e-16 5.225327e-14) OK.
Max cell openness = 3.308378e-15 OK.
Max aspect ratio = 66.99643 OK.
Minimum face area = 3.874454e-06. Maximum face area = 8.968646. Face area magnitudes OK.
Min volume = 1.148255e-06. Max volume = 11.81478. Total volume = 2.849739e+07. Cell volumes OK.
Mesh non-orthogonality Max: 63.7486 average: 4.455527
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 3.998489 OK.
Coupled point location match (average 0) OK.
Mesh OK.
End
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March 16, 2022, 06:32
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#2 |
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New Member
Join Date: Sep 2021
Posts: 6
Rep Power: 4 |
Solution:
Increase the MRF domain (non inertial) to 2 blade diameters of lenght and 2 blade diameters of height with the blade in the middle |
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| Tags |
| mrf, simplefoam, wedge 120°, wind turbine blade |
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