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Mark March 3, 2003 06:33

Residual value
 
Hi all~

I have a convergence problem. My model is 1/8 model of axial fan. Cell numbers are 620000. During iteration, the residual values are not decreasing. They are oscillated or very slowly decraasing. What's wrong with my problem or What I need to do?

cjtune March 3, 2003 12:15

Re: Residual value
 
I think it's the consequence of using the less accurate implicit MRF over the explicit MRF method. You are using the implicit method, right?

I did this last time: start from a low RPM, then stop. Restart with a higher RPM, stop after awhile, and then restart with a even higher RPM and so on, until you reach the RPM you want. It didn't really converge at my ultimate RPM but at least the residuals are a magnitude lower than they were (ie. 'good enough' for me...). I think you can you the advanced transient module's load steps instead of stopping and restarting so many times.



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