| woodie |
May 25, 2022 12:02 |
SRFPimpleFoam
2 Attachment(s)
Hello everybody,
I am currently trying to do a transient simulation of a wind turbine rotor blade in a single reference frame (SRF) using SRFPimpleFoam (OF-v2112 and v1912).
Before, i already managed to get a steady-state solution using SRFSimpleFoam.
However, as i start SRFPimpleFoam, the values for the pressure go through the roof immediately (the solver keeps running though, but produces an unphysical solution).
I have all the same Mesh and BC as in the steady case, so i really dont understand why these problems occur at all.
Maybe someone has an idea why this is the case.
I will provide more details about my case below.
General Setup:
- 120°-domain in a SRF (see. Fig.1)
- cyclicAMI on rotational symmetry planes (side_left, side_right)
- initialized with the results obtained with SRFSimpleFoam
- Turbulence Model: SSTLM
The Problem:
- extremely high pressure, already after first iteration
SRFSimpleFoam gives values for pressure between -5e3 and 2e3, after the
first time step of SRFPimpleFoam i get values between +-2e8. -> see Fig.2
- rest of the fields does not seem to be affected
- seems like the cyclicAMI patches could be the problem?
Things i changed compared to steady case:
- controlDict:
Code:
application SRFPimpleFoam;
startFrom latestTime;
deltaT 1e-8;
- fvSchemes: ddtScheme = Euler
- fvSolution:
I also have tried having more OuterCorrectors and control the loop with residualControl.
Code:
PIMPLE
{
momentumPredictor yes;
nNonOrthogonalCorrectors 2;
nOuterCorrectors 3;
nCorrectors 3;
consistent yes;
pRefCell 0;
pRefValue 0;
turbOnFinalIterOnly false;
correctPhi true;
...
}
The log-file for the first iteration:
HTML Code:
Create time
Create mesh for time = 0
PIMPLE: max iterations = 3
field p : relTol 0, tolerance 0.0001
field Urel : relTol 0, tolerance 1e-06
field "(k|omega|ReThetat|gammaInt)" : relTol 0, tolerance 1e-06
Reading field p
Reading field Urel
Reading/calculating face flux field phi
AMI: Creating addressing and weights between 59136 source faces and 55552 target faces
AMI: Patch source sum(weights) min:0.999999 max:1 average:1
AMI: Patch target sum(weights) min:0.999986 max:1 average:1
Creating SRF model
Selecting SRFModel rpm
Selecting incompressible transport model Newtonian
Selecting turbulence model type RAS
Selecting RAS turbulence model kOmegaSSTLM
Selecting patchDistMethod meshWave
bounding k, min: 0 max: 946.983 average: 2.30207
Employing decay control with kInf:kInf [0 2 -2 0 0 0 0] 6.5e-05 and omegaInf:omegaInf [0 0 -1 0 0 0 0] 16.36
kOmegaSSTLMCoeffs
{
a1 0.28;
b1 1;
c1 10;
F3 no;
ca1 2;
ca2 0.06;
ce1 1;
ce2 50;
cThetat 0.03;
sigmaThetat 2;
lambdaErr 1e-06;
maxLambdaIter 60;
decayControl yes;
kInf 6.5e-05;
omegaInf 16.36;
alphaK1 0.85;
alphaK2 1;
alphaOmega1 0.5;
alphaOmega2 0.856;
gamma1 0.555556;
gamma2 0.44;
beta1 0.075;
beta2 0.0828;
betaStar 0.09;
}
No finite volume options present
Starting time loop
forces forces:
rho: rhoInf
Freestream density (rhoInf) set to 1.225
Not including porosity effects
Courant Number mean: 1.75657e-06 max: 0.20131
Time = 1e-08
PIMPLE: iteration 1
DILUPBiCGStab: Solving for Urelx, Initial residual = 3.61499e-11, Final residual = 5.13285e-33, No Iterations 4
DILUPBiCGStab: Solving for Urely, Initial residual = 4.49548e-10, Final residual = 1.59125e-31, No Iterations 4
DILUPBiCGStab: Solving for Urelz, Initial residual = 5.0328e-11, Final residual = 6.55993e-33, No Iterations 4
GAMG: Solving for p, Initial residual = 0.999989, Final residual = 0.0082096, No Iterations 12
GAMG: Solving for p, Initial residual = 0.0204345, Final residual = 0.000194422, No Iterations 61
GAMG: Solving for p, Initial residual = 0.00678058, Final residual = 6.68389e-05, No Iterations 61
time step continuity errors : sum local = 5.92363e-15, global = 4.22576e-16, cumulative = 4.22576e-16
GAMG: Solving for p, Initial residual = 0.00239474, Final residual = 2.34477e-05, No Iterations 79
GAMG: Solving for p, Initial residual = 0.00106585, Final residual = 1.0611e-05, No Iterations 89
GAMG: Solving for p, Initial residual = 0.000464535, Final residual = 4.64077e-06, No Iterations 155
time step continuity errors : sum local = 4.1481e-16, global = -8.04959e-19, cumulative = 4.21771e-16
GAMG: Solving for p, Initial residual = 0.000224096, Final residual = 2.31606e-06, No Iterations 300
GAMG: Solving for p, Initial residual = 0.000105327, Final residual = 1.4517e-06, No Iterations 300
DICPCG: Solving for p, Initial residual = 5.24223e-05, Final residual = 9.96327e-07, No Iterations 136
time step continuity errors : sum local = 8.91004e-17, global = 3.39321e-18, cumulative = 4.25164e-16
DILUPBiCGStab: Solving for omega, Initial residual = 1.42567e-15, Final residual = 3.97108e-30, No Iterations 3
DILUPBiCGStab: Solving for k, Initial residual = 1.12692e-11, Final residual = 1.63946e-27, No Iterations 3
bounding k, min: -1.75187e-10 max: 946.84 average: 2.30206
DILUPBiCGStab: Solving for ReThetat, Initial residual = 2.3811e-09, Final residual = 5.1669e-28, No Iterations 3
DILUPBiCGStab: Solving for gammaInt, Initial residual = 3.48693e-10, Final residual = 4.30537e-31, No Iterations 3
PIMPLE: iteration 2
DILUPBiCGStab: Solving for Urelx, Initial residual = 4.25948e-06, Final residual = 1.35464e-31, No Iterations 4
DILUPBiCGStab: Solving for Urely, Initial residual = 3.87176e-05, Final residual = 7.55888e-30, No Iterations 4
DILUPBiCGStab: Solving for Urelz, Initial residual = 4.06583e-06, Final residual = 1.66793e-31, No Iterations 4
GAMG: Solving for p, Initial residual = 0.224347, Final residual = 0.00203955, No Iterations 7
GAMG: Solving for p, Initial residual = 0.0155198, Final residual = 0.000149521, No Iterations 75
GAMG: Solving for p, Initial residual = 0.00587188, Final residual = 5.64349e-05, No Iterations 53
time step continuity errors : sum local = 3.79089e-15, global = -2.83492e-16, cumulative = 1.41672e-16
GAMG: Solving for p, Initial residual = 0.0024005, Final residual = 2.334e-05, No Iterations 65
GAMG: Solving for p, Initial residual = 0.0010719, Final residual = 1.04598e-05, No Iterations 67
GAMG: Solving for p, Initial residual = 0.000496189, Final residual = 4.94625e-06, No Iterations 89
time step continuity errors : sum local = 3.30134e-16, global = -1.57436e-17, cumulative = 1.25929e-16
GAMG: Solving for p, Initial residual = 0.000235522, Final residual = 2.34465e-06, No Iterations 150
GAMG: Solving for p, Initial residual = 0.000113833, Final residual = 1.1541e-06, No Iterations 300
DICPCG: Solving for p, Initial residual = 5.60628e-05, Final residual = 9.92177e-07, No Iterations 118
time step continuity errors : sum local = 6.62022e-17, global = -2.44787e-18, cumulative = 1.23481e-16
DILUPBiCGStab: Solving for omega, Initial residual = 3.96401e-16, Final residual = 9.82392e-31, No Iterations 3
DILUPBiCGStab: Solving for k, Initial residual = 9.78711e-12, Final residual = 9.84719e-28, No Iterations 3
bounding k, min: 0 max: 946.689 average: 2.30207
DILUPBiCGStab: Solving for ReThetat, Initial residual = 5.55254e-10, Final residual = 2.83376e-28, No Iterations 3
DILUPBiCGStab: Solving for gammaInt, Initial residual = 6.20827e-11, Final residual = 9.70914e-31, No Iterations 3
PIMPLE: converged in 2 iterations
ExecutionTime = 374.59 s ClockTime = 375 s
forces forces write:
Sum of forces
Total : (1.61885e+07 -2.42372e+07 7.42024e+06)
Pressure : (1.61885e+07 -2.42372e+07 7.4202e+06)
Viscous : (-49.2526 49.8269 37.1996)
Sum of moments
Total : (-2.93299e+07 3.23877e+08 3.04495e+06)
Pressure : (-2.93289e+07 3.23878e+08 3.04493e+06)
Viscous : (-983.493 -1277.54 19.7219)
volFieldValue minmaxdomain_scalar write:
volFieldValue mindomain_scalar write:
min(region0) of p = -2.11475e+08
volFieldValue maxdomain_scalar write:
max(region0) of p = 2.36003e+08
Miscellaneous:
- SRFProperties:
Code:
SRFModel rpm;
origin (0 0 0);
axis (0 1 0);
rpmCoeffs
{
rpm 15;
}
- boundary
Code:
7
(
BLADE
{
type wall;
inGroups 1(wall);
nFaces 84769;
startFace 46191188;
}
INLET
{
type patch;
inGroups 1(patch);
nFaces 59648;
startFace 46275957;
}
HUB
{
type patch;
inGroups 1(patch);
nFaces 59693;
startFace 46335605;
}
OUTLET
{
type patch;
inGroups 1(patch);
nFaces 59648;
startFace 46395298;
}
SIDE_LEFT
{
type cyclicAMI;
inGroups 1(cyclicAMI);
nFaces 59136;
startFace 46454946;
matchTolerance 0.0001;
transform rotational;
neighbourPatch SIDE_RIGHT;
rotationAxis (0 1 0);
rotationCentre (0 0 0);
}
SIDE_RIGHT
{
type cyclicAMI;
inGroups 1(cyclicAMI);
nFaces 55552;
startFace 46514082;
matchTolerance 0.0001;
transform rotational;
neighbourPatch SIDE_LEFT;
rotationAxis (0 1 0);
rotationCentre (0 0 0);
}
TOP
{
type patch;
inGroups 1(patch);
nFaces 62904;
startFace 46569634;
}
)
- BC:
Urel:
inlet - SRFVelocity,
top - SRFFreestreamVelocity,
outlet - pressureInletOutletVelocity
blade - noSlip
p:
outlet - fixedValue
zeroGradient everywhere else
Thanks in advance, let me know if more information is needed :)
Christoph
Figures: |
