RMS fluctuation

saeedabedi · April 8, 2013, 10:44

Hi all

I am attempting to simulate flow over a submnarine at a constant speed.

I am using ANSYS CFX, k omega or SST turbulence model, A structured mesh with icem.

When I have coarse mesh it solves and RMS residual converges however when I have fne mesh RMS residual will not converge and there is fluctuation in RMS.

Can anyone offer some advice from previous expeience?

Cheers,

Saeed

ghorrocks · April 8, 2013, 18:22

Here's plenty of advice: http://www.cfd-online.com/Wiki/Ansys...gence_criteria

Your comments agree with the expected behaviour described in this FAQ.

April 8, 2013, 10:44	RMS fluctuation	#1
saeedabedi New Member saeed Join Date: Apr 2013 Posts: 4 Rep Power: 13	Hi all I am attempting to simulate flow over a submnarine at a constant speed. I am using ANSYS CFX, k omega or SST turbulence model, A structured mesh with icem. When I have coarse mesh it solves and RMS residual converges however when I have fne mesh RMS residual will not converge and there is fluctuation in RMS. Can anyone offer some advice from previous expeience? Cheers, Saeed

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April 8, 2013, 18:22		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Here's plenty of advice: http://www.cfd-online.com/Wiki/Ansys...gence_criteria Your comments agree with the expected behaviour described in this FAQ.