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-   -   Converge issue on steady state pump (http://www.cfd-online.com/Forums/cfx/106075-converge-issue-steady-state-pump.html)

eleazar August 17, 2012 11:32

Converge issue on steady state pump
 
I have a mesh of a pump that has Boundary layers on the parts : blade, hub, shroud. it has periodic walls and inlet/outlet.

The BL mesh has elements with aspect ratio of 20000 and a number of jacobian with 0.42 the smaller.

I try to run this pump on CFX and the solver can not converge at the timestep of 1/ω, I am using SST as turbolence model.

If i apply timestep at 1e-9 the solver converge but the results are really bad.

Do you think that might be the mesh that creates the issue? or i have to check something else?

ghorrocks August 18, 2012 07:35

An aspect ratio of 20000 is pretty bad, even in a boundary layer mesh. I agree with you, I suspect you have inadequate mesh quality.


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