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## Message Boards

### RE: Residual currents

CL

#### Residual currents

Youngling Posts: 11 Join Date: 9/3/12
Hi, there,

Sorry for this very tiny question here:
I had set up a D3D Flow model and calibrated it. I hope to plot the residual currents vectors (or somebody calls it circulation map??). I already tried Quickplot, unsucessful. Could you please give me a suggestion?
Many thanks.

Cathy
CL
##### Cathy liu, modified 5 Years ago.

Youngling Posts: 11 Join Date: 9/3/12
I am still waiting for your kind help to solve this problem. As the residual currents map is very important to the study of sediment transport, I am so keen to make it using D3D. It can be calculated using the MIKE 21 and 3DD modules (a module developed by original ASR) easily. Many thanks for your help.
Cathy
JL

#### RE: Residual currents

Padawan Posts: 70 Join Date: 3/30/11
Dear Cathy,

Have a look in A.2.30 of the Delf3D-Flow manual. Using the Fourier option the model can output a mean current during a certain interval. You can adjust the interval to average out the oscillating part of your current.
Other than that you have to use some kind of low pass filtering or tidal analysis and subtraction in post-processing in matlab or equivalent.

Hope that helps,

João.
CL
##### Cathy liu, modified 5 Years ago.

Youngling Posts: 11 Join Date: 9/3/12
Hi João,

Thank you very much. That is very helpful. I was already in the process to write some matlab codes to calculate the residual currents. However, I still believe there must be some other methods easier and handier.

Cheers.

Cathy
MI

#### RE: Residual currents

Youngling Posts: 2 Join Date: 2/11/19

Can you please help me in finding out the residual currents in Delft 3d. I read the flow manual but couldnt understand how to find out the residual current

PS

#### RE: Residual currents

Padawan Posts: 44 Join Date: 12/4/18

Hi Cathy.  You need to enable Fourier Analysis in the outputs tab, and follow the guidance in Appendix A.3.29 ...... it looks more complicated to set up than it actually is! I attach an example .fou file in case it helps.

### Attachments:

MI

#### RE: Residual currents

Youngling Posts: 2 Join Date: 2/11/19

Hello Mr Shepperd,

Can u be little more simpler? I am a beginner to Delft 3D. I didnt find Appendix A.3.29 in flow manual. How can I open the fou file that u have attached?

Thank you

Mathew Isac