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-   -   Basic Question on Convergence (http://www.cfd-online.com/Forums/fluent/30109-basic-question-convergence.html)

Anshul August 1, 2002 17:55

Basic Question on Convergence
 
Hello

I am studying chaotic mixing in microchannels. My model is 200 microns wide, 100 microns high, and 1500 microns long. My velocity is 2 cm/s.

I used a hexahedral submap mesh with a spacing of 5 microns to give me 256000 cells.

I am looking at just velocity fields, and then applying a UDS species.

I want to converge my flow to a level that is appropriate. How do I determine this? My residual plots keep decreasing. Are they supposed to level out? I've done 700 iterations and it gets to 1e-8 and is still decreasing. Do I need more iterations? What timestep should I be using? How do I input that?

thanks very much. I am new.

anshul

Christian August 2, 2002 02:14

Re: Basic Question on Convergence
 
Hi. You can create a surface plot where you can monitor values of say temperature in a point or a surface. That might help you to determine if your case has converged.

Cheers Christian


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