[farzadmech]

How to calculate energy spectrum for a Homogenous Isotropic turbulence (HIT) at specific time in a rectangular shape?

Hello all
I have two questions;
1- First of all, is it possible to generate HIT inside a rectangle? If so, it is called HIT again?
2- if Nx=Nz but Ny is different, How can I calculate power spectrum?
when Nx=Ny=Nz, it is possible to use below openfoam algorithm;https://www.openfoam.com/documentati...8C_source.html
but in my case Nx=Nz =/ Ny
Thanks,
Farzad

[farzadmech]

There was a bug in the original functionObject "energySpectrum.c" in line 167;

 N_ = Vector<int>
    (
        round(nCellXYZ.x()),
        round(nCellXYZ.z()), //round(nCellXYZ.y()) is the correct one
        round(nCellXYZ.z())
    );

Now, if the mesh size remain constant(no expansion ratio), code calculates powerSpectrum but when it is Nx=Ny=Nz it is totally different from when it is Dx=Dy=Dz. see below figure.


Thanks,
Farzad

Originally Posted by farzadmech

How to calculate energy spectrum for a Homogenous Isotropic turbulence (HIT) at specific time in a rectangular shape?

Hello all
I have two questions;
1- First of all, is it possible to generate HIT inside a rectangle? If so, it is called HIT again?
2- if Nx=Nz but Ny is different, How can I calculate power spectrum?
when Nx=Ny=Nz, it is possible to use below openfoam algorithm;https://www.openfoam.com/documentati...8C_source.html
but in my case Nx=Nz =/ Ny
Thanks,
Farzad