Temporal averaged velocity field

[mwkim]

Dear OpenLB users and developers,

I am performing simulations for external flows over an infinite wing.

After completing a stable simulation setup, I now want to obtain temporally averaged flow fields, particularly velocity fields.

The current case also uses a wall model, so I am referring to the “channel3d” case. However, the data are not contained in the output VTK files.

The relevant code lines are attached below.

using DESCRIPTOR = D3Q19<POROSITY,VELOCITY,TENSOR,AVERAGE_VELOCITY>;

.....

int iTstartAvg = converter.getLatticeTime( maxPhysT*0.4 );
  if (iT == iTstartAvg) {
    SuperLatticePhysVelocity3D<T,DESCRIPTOR> latticeVelocity(sLattice, converter);
    sLattice.defineField<AVERAGE_VELOCITY>(superGeometry.getMaterialIndicator({1}), latticeVelocity);
  }
  if (iT < iTstartAvg) {
    sLattice.setParameter<descriptors::LATTICE_TIME>(2);
  }
  else {
    sLattice.setParameter<descriptors::LATTICE_TIME>(iT - iTstartAvg + 1);
  }

SuperLatticePhysExternalVectorField3D<T,DESCRIPTOR,AVERAGE_VELOCITY> sAveragedVel(sLattice, converter.getConversionFactorVelocity(),"aVel");
vtmWriter.addFunctor( sAveragedVel );

......

If anyone can correct my mistakes or suggest some guidance, I would deeply appreciate it.

Sincerely,

[Yuji]

Hello,
Thank you for your post in the forum.
Could you please show me which dynamics you use?

[Yuji]

If you use wall function as well as channel case, you need setting true in wallModelParameters.turbulenceStatistics

[mwkim]

Thank you for your comments.

I was playing with 1.8.1 version. But, I noticed “turbulenceStatistics” is newly implemented in 1.9.0 version from your comments.
I set it as true while NaN values are stored in the averaged velocity variables.
I am finding any errors in my modified code (I modified the code structure from 1.8.1 to 1.9.0).
If I still experience problems despite having no errors in my code, I would kindly ask for your help, if you don’t mind.

[Yuji]

OK, you can ask me anytime in this forumu.

[Author]

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