[jabbath]

Hi,

I have been trying to simulate a NREL 5MW reference turbine using rotorDiskSource. I seem to get good results when running on a single processor. But when I decompose and run, the turbine's wake completely disappears. I've noticed that in the decomposed case the rotorDiskSource output shows effective lift = 0, when in the single processor case it is around 100k.

otorDisk output:
    min/max(AOA)   = 1.65132, 1.71517
    Effective drag = -5011.09
    Effective lift = 0
GAMG:  Solving for Ux, Initial residual = 1.00076e-06, Final residual = 1.00076e-06, No Iterations 0
GAMG:  Solving for Uy, Initial residual = 7.42757e-06, Final residual = 7.42757e-06, No Iterations 0
GAMG:  Solving for Uz, Initial residual = 7.49477e-06, Final residual = 7.49477e-06, No Iterations 0
GAMG:  Solving for T, Initial residual = 2.87311e-06, Final residual = 2.87311e-06, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 0.000266345, Final residual = 2.55409e-06, No Iterations 18
time step continuity errors : sum local = 1.94881e-10, global = 1.05977e-15, cumulative = -1.00503e-09
GAMG:  Solving for p_rgh, Initial residual = 6.00008e-06, Final residual = 9.16971e-07, No Iterations 6
time step continuity errors : sum local = 6.99648e-11, global = -5.42417e-15, cumulative = -1.00503e-09
ExecutionTime = 17.06 s  ClockTime = 18 s

and here is my decomposeParDict:

#include "../meshSetup"

numberOfSubdomains  $nDomains;
// method          scotch;
// method          hierarchical;
// method          simple;
method          $method;
// method          metis;
// method          manual;
// method          multiLevel;
// method          structured;  // does 2D decomposition of structured mesh

multiLevelCoeffs
{
    // Decomposition methods to apply in turn. This is like hierarchical but
    // fully general - every method can be used at every level.

    level0
    {
        numberOfSubdomains  64;
        //method simple;
        //simpleCoeffs
        //{
        //    n           (2 1 1);
        //    delta       0.001;
        //}
        method scotch;
    }
    level1
    {
        numberOfSubdomains  4;
        method scotch;
    }
}

// Desired output

simpleCoeffs
{
    n           ($Sx $Sy $Sz);
    delta       0.001;
}

hierarchicalCoeffs
{
    n           (1 2 1);
    delta       0.001;
    order       xyz;
}

metisCoeffs
{
 /*
    processorWeights
    (
        1
        1
        1
        1
    );
  */
}

scotchCoeffs
{
    //processorWeights
    //(
    //    1
    //    1
    //    1
    //    1
    //);
    //writeGraph  true;
    //strategy "b";
}

manualCoeffs
{
    dataFile    "decompositionData";
}

structuredCoeffs
{
    // Patches to do 2D decomposition on. Structured mesh only; cells have
    // to be in 'columns' on top of patches.
    patches     (bottomPatch);
}

where $Sx, $Sy, and $Sz = 4, $nDomains=64, and $method = simple.

Below is the relevant portion of my fvOptions:

disk
{
    type            rotorDisk;
    active          on;

    rotorDiskCoeffs
    {
        selectionMode   cellSet;
        cellSet        turbine1;

        fields      (U);    // Names of fields on which to apply source
        nBlades         3;      // Number of blades
        tipEffect       0.96;   // Normalised radius above which lift = 0

        inletFlowType   local;  // Inlet flow type specification

        geometryMode    specified;

        origin          (0 0 0);
        axis            (1 0 0);

        refDirection    (0 0 1);  // Reference direction
                                  // - used as reference for psi angle
        rpm             12.1;

        trimModel       fixedTrim;  // fixed || targetForce

        rhoRef          1.225;
        rhoInf          1.225;

        fixedTrimCoeffs
        {
             theta0         0;
             theta1c        0;
             theta1s        0;
        }

        flapCoeffs
        {
            beta0           0;  // Coning angle [deg]
            beta1c          0;  // Lateral flapping coeff (cos coeff)
            beta2s          0;  // Longitudinal flapping coeff (sin coeff)
        }

Any help would be greatly appreciated!

[k.vimalakanthan]

Hi Jabbath,

I'm faced with the same issue? were you able to simulate the NREL5MW rotor with rotorDiskSource on parallel.. could you please share your files?

many thanks in advance,
Kind regards,
Kishore

[HPE]

Hi,

Could you please open a bug-issue with a minimal reproducible example in https://develop.openfoam.com/?

Many thanks.

[k.vimalakanthan]

Originally Posted by HPE

Hi,

Could you please open a bug-issue with a minimal reproducible example in https://develop.openfoam.com/?

Many thanks.

Thank you! I'll do that, in the mean time if anyone has any sample wind turbine simulation setup using rotorDiskSource, please help by sharing it.. I'm also trying to simulate the NREL 5MW rotor using OF v8, but I suspect it requires some modification to the class to switch the propeller setup to wind turbine..