[wyungh]

Hi everyone，
I am using ANSYS Fluent 14.5, now I want to obtain the fluctuating velocity and I want to monitor and write to file the velocity fluctuations u', v' and w'.
I used the DES turbulence model in Fluent.

Anybody know how I can obtain the fluctuating velocity?

Thanks.

[LuckyTran]

Do you want the instantaneous quantities or the rms statistics?

For instantaneous quantities:
You cannot export only the fluctuating velocities u', v', and w'. In order to do the decomposition the mean velocity must be known (in general it is not known beforehand).

You will have to export the instantaneous velocities u(t), v(t), and w(t) and then post-process the results to obtain the fluctuating components.