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-   -   [ANSYS Meshing] edge sizing control--Calculate cell-to-cell expansion rate from bias factor (http://www.cfd-online.com/Forums/ansys-meshing/88361-edge-sizing-control-calculate-cell-cell-expansion-rate-bias-factor.html)

la7low May 15, 2011 10:42

edge sizing control--Calculate cell-to-cell expansion rate from bias factor
 
Hi Everyone,

could someone tell me how to calculate first cell height and cell-to-cell growth rate from bias factor and number of cells?

It would be very important. Anyway why does the Workbench Mesher use this kind of sizing (with bias factor) on the edges? Cell height and growth rate of successive cells is more useful IMO.

Thanks for the answer in advance!

la7low May 15, 2011 12:11

ohh I got it
 
I figured it out...

Using the following notations:

Edge length L
Number of cells n
Total expansion ratio r (=bias factor in Ansys Meshing)
Cell-to-cell expansion k (or geometric growth ratio)
Start cell size ds
End cell size de

The equations to be fulfilled:
L=sum(ds*k^i), i=0..n-1
de/ds=r=k^(n-1)

From the above 3 equations any 3 of the 6 unknown mesh parameters can be calculated.

See this thread too where a guy made a code to carry out the calculations for any known-unknown combinations of the 6 parameters.
http://www.cfd-online.com/Forums/ope...alculator.html

asurpam August 20, 2012 07:43

Can you explain it in more detail


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