k-e convergence criteria

aras · May 19, 2011, 23:53

I am solving a turbulence flow inside a pipe with many steps, complexities including lots of walls.

I am getting good convergence (below 1e-3) for velocities, and continuity.

but k and e are fluctuating in the range of 1e-2, is it ok? and generally what is the satisfactory range of convergence for k and e?

thx

alastormoody11 · May 20, 2011, 06:29

Hi,

Have you checked the validity of your mesh for using the k-e model, check whether the wall y plus values are in accordance with the recommended values suggested in the FLUENT manual.

I think the default values for the residuals are good enough. I would not recommend that you use unconverged results.

aras · May 20, 2011, 08:53

so, do you know what are the recommended y+ in fluent for k-e?

swiftaircraft · May 21, 2011, 08:44

This is clearly specified in the help files provided with Fluent

May 19, 2011, 23:53	k-e convergence criteria	#1
aras New Member araz Join Date: May 2011 Location: Toronto, Canada Posts: 19 Rep Power: 14	I am solving a turbulence flow inside a pipe with many steps, complexities including lots of walls. I am getting good convergence (below 1e-3) for velocities, and continuity. but k and e are fluctuating in the range of 1e-2, is it ok? and generally what is the satisfactory range of convergence for k and e? thx

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May 20, 2011, 06:29		#2
alastormoody11 Senior Member Join Date: Jun 2009 Posts: 100 Rep Power: 16	Hi, Have you checked the validity of your mesh for using the k-e model, check whether the wall y plus values are in accordance with the recommended values suggested in the FLUENT manual. I think the default values for the residuals are good enough. I would not recommend that you use unconverged results.

May 20, 2011, 08:53		#3
aras New Member araz Join Date: May 2011 Location: Toronto, Canada Posts: 19 Rep Power: 14	so, do you know what are the recommended y+ in fluent for k-e?

May 21, 2011, 08:44		#4
swiftaircraft Member David Stanbridge Join Date: Apr 2010 Location: Norwich, UK Posts: 59 Rep Power: 16	This is clearly specified in the help files provided with Fluent