CFD Online Discussion Forums - Averaging due to parallel running

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- OpenFOAM Programming & Development (https://www.cfd-online.com/Forums/openfoam-programming-development/)

- - Averaging due to parallel running - cuttingPlane (https://www.cfd-online.com/Forums/openfoam-programming-development/82878-averaging-due-parallel-running-cuttingplane.html)

Averaging due to parallel running - cuttingPlane

Dear All,

I am actually implementing a boundary condition that accesses some Field values like p, U, rho from cutting planes inside the mesh. As only the average of the cut Field is of interest, I have to create some kind of weighting factor for each processor part.

So far the Code looks like this:

Code:

   // Create the cutting Planes

   point planeLocation = planeLocations[planeI];

   plane extPlane(planeLocation,orientPatch);

   cuttingPlane cuttedPlane(extPlane,this->dimensionedInternalField().mesh());

    

   vector averageUPRho(0.0,0.0,0.0);



   scalar weigthPatch;



   // Compute the the cut of each processor

   if (cuttedPlane.cut()== 1)

   {

    

    averageUPRho.component(0)= (average(cuttedPlane.sample(Ufield)) & orientPatch); // The mean Velocity in normal Direction

    averageUPRho.component(1)= average(cuttedPlane.sample(pfield));// The mean Pressure

    averageUPRho.component(2)=average(cuttedPlane.sample(rhofield));// The mean Density 

    weigthPatch= cuttedPlane.size(); // The weighting factor

    }

    else

    {

    weigthPatch=0;

    }

Now I forward the averageUPRho and the weigthPatch to the Master and do the averaging with

rhoMean=sum(averageUPRho*weigthPatch)/sum(weigthPatch);

unfortunately I weight by the number of faces and not by their Area (magSf for patches works ... not for planes?).

How can I acces them??

Any hints?

I notice that sampledPlane inherits from sampledSurface and cuttingPlane. sampledSurface has an area() function. Would that help you? Could you create a sampledPlane from your plane?

It worked...

just adding / editing 2 lines...

Code:

...



cuttingPlane cuttedPlane(extPlane,this->dimensionedInternalField().mesh());

sampledPlane smpPl("smpPl",this->dimensionedInternalField().mesh(),extPlane);

....

averageUPRho.component(2)=average(cuttedPlane.sample(rhofield));

weigthPlane= sum(smpPl.magSf());

}

...

You can replace weightPlane with smpPI.area()

Also because samplePlane inherits from cuttingPlane, you probably don't need cuttedPlane and can just use smpPI?

Hi Laurence,

Thanks for the reply...

Quote:

Originally Posted by l_r_mcglashan (Post 286564)

You can replace weightPlane with smpPI.area()

area() unfortunately passes the total plane magnitude, not only the part a processor contains ....:mad:

Quote:

Originally Posted by l_r_mcglashan (Post 286564)

Also because samplePlane inherits from cuttingPlane, you probably don't need cuttedPlane and can just use smpPI?

...this works fine...:)

Thanks so far...