CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums

Search Results

Register Blogs Members List Search Today's Posts Mark Forums Read

Showing results 1 to 5 of 5
Search took 0.00 seconds.
Search: Posts Made By: FMDenaro
Forum: Main CFD Forum August 14, 2013, 05:29
Replies: 13
Views: 1,418
Posted By FMDenaro
just did a test on your data file that contains...

just did a test on your data file that contains 20000 values of u,v,w sampled each 20*dt = 10^-4 s.
I used my FFT code, first on the window [1:500], then on the full sampled window [1:20000].
You...
Forum: Main CFD Forum August 13, 2013, 17:22
Replies: 13
Views: 1,418
Posted By FMDenaro
Yes, I considered the time step of the...

Yes, I considered the time step of the computation but even if you stored each 20 time steps then your FFT extends until pi/(20*dt)= pi/10^-4 =3.14 x 10^4 ...
Therefore, your FFT does not work on...
Forum: Main CFD Forum August 13, 2013, 05:52
Replies: 13
Views: 1,418
Posted By FMDenaro
Assuming that your dt is fixed, your spectra...

Assuming that your dt is fixed, your spectra should extend until the Nyquist frequency pi/dt, could you check that your FFT extends up to such frequency?
Changing the temporal window, only the time...
Forum: Main CFD Forum August 8, 2013, 04:45
Replies: 13
Views: 1,418
Posted By FMDenaro
energy equilibrium is in your case equivalent to...

energy equilibrium is in your case equivalent to a statistical steady state.
However I have somehow the feeling that you are using the FFT in a wrong way.
For example, if your time step is dt =...
Forum: Main CFD Forum August 6, 2013, 04:36
Replies: 13
Views: 1,418
Posted By FMDenaro
did you perform FFT of velocity components at...

did you perform FFT of velocity components at some fixed position x for some time interval, right?

1) what about the temporal window?
2) what about u,v,w at same location?
3) did you average...
Showing results 1 to 5 of 5

 
Forum Jump

All times are GMT -4. The time now is 21:17.