[huangxianbei]

Originally Posted by aylalisa

I started from this thread too but I am still looking for the reason why the result does not agree with :-(

Hi, I make a further calculation and find that the two ways reach the same result. Maybe there is something wrong in my previous case.

wallShearStressLES -2.99E-006
wallGradU 2.986512890625E-006

So the magnitude is the same, however, the sign is opposite
due to

forAll(wallShearStress.boundaryField(), patchI)
    {
        wallShearStress.boundaryField()[patchI] =
        (
           -mesh.Sf().boundaryField()[patchI]
           /mesh.magSf().boundaryField()[patchI]
        ) & Beff.boundaryField()[patchI];
    }

[Elham]

Originally Posted by huangxianbei

Hi, I make a further calculation and find that the two ways reach the same result. Maybe there is something wrong in my previous case.

wallShearStressLES -2.99E-006
wallGradU 2.986512890625E-006

So the magnitude is the same, however, the sign is opposite
due to

forAll(wallShearStress.boundaryField(), patchI)
    {
        wallShearStress.boundaryField()[patchI] =
        (
           -mesh.Sf().boundaryField()[patchI]
           /mesh.magSf().boundaryField()[patchI]
        ) & Beff.boundaryField()[patchI];
    }

Dear huangxianbei

How do you use the above code, in controlDict or as a postProcessing command?
I need to calculate u_tau and yplus and I want to know how I can calculate them for a LES model.

Thanks,

Elham