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-   -   finer mesh never achieved convergence of total energy (https://www.cfd-online.com/Forums/fluent/182296-finer-mesh-never-achieved-convergence-total-energy.html)

ngonbadipoor@yahoo.com January 6, 2017 04:26

finer mesh never achieved convergence of total energy
 
Hi
I am modeling a 3 D laminar flow in a pipe with constant Heat flux (H2). to check the converging situation I choose several items .e.g. on a created point I select a surface-monitoring of vertex average of total energy . when running a convergence history for finest mesh never achieved while for coarser mesh had achieved before. I will be glad to know why?
thanks

LuckyTran January 6, 2017 10:55

Check your mesh quality. Fine meshes generally have higher potential for greater # of skewed cells (since there is an overall greater number of total cells). Skewed cells will mess things up.

Fine meshes converge slower than coarse meshes.
Fine meshes are inherently more unstable than coarse meshes (because there is less numerical dissipation).

The finer your mesh, the greater the importance of it needing to be high quality.

ngonbadipoor@yahoo.com January 7, 2017 01:35

1 Attachment(s)
thanks LuckyTran
I attached the mesh metric. please let me know what you think
thanks
[IMG]file:///C:/Users/navid/AppData/Roaming/Ansys/v160/preview.png[/IMG]


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