CFX residual bouncing

wind81 · March 16, 2012, 02:02

Hi, i'm doing the simulation of the spray with water mist. Initally i'm using mass flow rate of 2g/s of injected water mist, the solver is steady and converge, When i increase the mass flow rate of the injected water mist to 200g/s, I'm facing the convergence issue and the residual is bouncing as shown in the attachment. May i know how can i resolve this issue? Any one can help me? Thanks.

hosseinhgf · March 16, 2012, 02:32

i think with decreasing time scale.

wind81 · March 16, 2012, 03:36

Hi, thanks for your reply. Currently, i'm using auto time scale, should i change to physical time scale, and use small time step?
Thanks.

ghorrocks · March 16, 2012, 04:27

Quote:

i think with decreasing time scale.

In general this is wrong and will make it worse.

Try reading this FAQ: http://www.cfd-online.com/Wiki/Ansys...gence_criteria

wind81 · March 16, 2012, 04:49

Hi, Thanks for your reply ghorrocks. now i trying with larger physical time, see whether it work or not..

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March 16, 2012, 02:32		#2
hosseinhgf Member h-h Join Date: Sep 2009 Posts: 38 Rep Power: 16	i think with decreasing time scale.

March 16, 2012, 03:36		#3
wind81 New Member wind Join Date: Feb 2012 Posts: 16 Rep Power: 14	Hi, thanks for your reply. Currently, i'm using auto time scale, should i change to physical time scale, and use small time step? Thanks.

March 16, 2012, 04:49		#5
wind81 New Member wind Join Date: Feb 2012 Posts: 16 Rep Power: 14	Hi, Thanks for your reply ghorrocks. now i trying with larger physical time, see whether it work or not..