[reespanau]

Hello all!

I want to plot the energy spectrum for my simulation, should I use probes? What should be the right step by step way to plot this energy spectrum, can I use the following command:

postProcess -func energySpectrum


Thank you!

[joshwilliams]

In the past, I have used the application "calcEk" from this repository (https://github.com/xuhanwustl/WrayAg...ilities/calcEk).

[reespanau]

Originally Posted by joshwilliams

In the past, I have used the application "calcEk" from this repository (https://github.com/xuhanwustl/WrayAg...ilities/calcEk).

Could you please explain to me how this app works? I'd appreciate it a lot!

[joshwilliams]

Originally Posted by reespanau

Could you please explain to me how this app works? I'd appreciate it a lot!

It reads your velocity field "U", then calls OpenFOAM's calcEk library ($FOAM_SRC/randomProcesses/fft/calcEk.C), which uses a fft to convert spatial velocity fluctuations at some time point to a spectra of energy [m^3/s^2] vs wave number [1/m].

[reespanau]

Do I need to compile this like a solver? with wmake

I have all my results for U already, I used pisoFoam. how do I run this library?

[joshwilliams]

Originally Posted by reespanau

Do I need to compile this like a solver? with wmake

I have all my results for U already, I used pisoFoam. how do I run this library?

Yes you need to compile it with wmake. This specific part is not a library, it is an application. Once you have compiled it you can run it with `calcEk' in the command line. It then takes your pre-computed results for U and converts it to a spectra for each saved timestep.

[farzadmech]

Thanks for the link. Can I use Of6 to compile it or I should install OF5 and then I use it? I tried to compile it with OF6 but it gives me lots of warnings.

Also, could you take a look to my problem in this thread?

Forced synthetic homogeneous isotropic turbulence(HIT) in OpenFOAM)

Originally Posted by joshwilliams

Yes you need to compile it with wmake. This specific part is not a library, it is an application. Once you have compiled it you can run it with `calcEk' in the command line. It then takes your pre-computed results for U and converts it to a spectra for each saved timestep.

[joshwilliams]

Originally Posted by farzadmech

Thanks for the link. Can I use Of6 to compile it or I should install OF5 and then I use it? I tried to compile it with OF6 but it gives me lots of warnings.

Also, could you take a look to my problem in this thread?

Forced synthetic homogeneous isotropic turbulence(HIT) in OpenFOAM)

Hi Farzad. I used it on OF6. I can't remember if I needed to modify it. Warnings are okay. If it gives some errors then of course something is wrong. I would say just try to run it then see if it works? It is the easiest way...