Improve Orthogonal Quality within Fluent

ptstorey · February 14, 2015, 10:04

I've done some shape optimisation (with adjoint solver) and the orthogonal quality has dropped from higher than 0.9 down to 0.5, and I'm beginning to see signs that the solution is struggling to converge.

What is the best way to refine/ improve orthogonal quality of the mesh?
So far I have tried Mesh > Smooth/Swap which has made it better, but I don't really know what I'm doing.

Thanks!

Tanmay95 · February 15, 2015, 11:16

It will be better if you can do it in your mesher.Using a finer mesh helps.

maverick123 · February 16, 2015, 02:37

Hi,

Read mesh in Fluent mesher. Use mesh/tool/auto-node-move command.
You can give a try with various dihedral angles.

Quote:

Originally Posted by ptstorey

I've done some shape optimisation (with adjoint solver) and the orthogonal quality has dropped from higher than 0.9 down to 0.5, and I'm beginning to see signs that the solution is struggling to converge.

What is the best way to refine/ improve orthogonal quality of the mesh?
So far I have tried Mesh > Smooth/Swap which has made it better, but I don't really know what I'm doing.

Thanks!

ptstorey · February 16, 2015, 08:51

Quote:

Originally Posted by Tanmay95

It will be better if you can do it in your mesher.Using a finer mesh helps.

My mesh is pretty fine already. My problem is that I can't take my .msh file back across to ICEM-CFD... unless you know a way of doing it?

Quote:

Originally Posted by maverick123

Hi,

Read mesh in Fluent mesher. Use mesh/tool/auto-node-move command.
You can give a try with various dihedral angles.

I haven't used Fluent mesher before, is it accessible from the Fluent main window?

Thanks for you replies

maverick123 · February 17, 2015, 02:22

Hi,

While launching Fluent standalone (not through WB) you can find toggle to launch in Meshing Mode.

ptstorey · February 17, 2015, 06:25

Ah I see. I'm currently working in 2D, and meshing mode isn't an option when selecting 2D. Is there a way around this?

Thanks

maverick123 · February 19, 2015, 05:00

Hi,

You can not modify 2D mesh in fluent meshing.

Quote:

Originally Posted by ptstorey

Ah I see. I'm currently working in 2D, and meshing mode isn't an option when selecting 2D. Is there a way around this?

Thanks

revilo82 · June 24, 2015, 08:54

I think the ortho quality (>0.1) is ok for CFD and Adjoint. After some optimization loops not only the mesh changed but the flow situation, too. That (could be) the reason for convergence issues. The question is, how does the "solution is struggling to converge"? Does it diverge, oscillate, do you see some instabilities, slow convergence, ... ?

prafulla145 · August 3, 2015, 12:57

orthogonal quality close to 1 is good, first try with default max face area, max and min sizing setting.If not then with trial and error obtain orthogonal quality close to 1. Orthogonal quality less than 0.001 is very poor.

February 14, 2015, 10:04	Improve Orthogonal Quality within Fluent	#1
ptstorey New Member Peter Storey Join Date: Oct 2014 Posts: 8 Rep Power: 11	I've done some shape optimisation (with adjoint solver) and the orthogonal quality has dropped from higher than 0.9 down to 0.5, and I'm beginning to see signs that the solution is struggling to converge. What is the best way to refine/ improve orthogonal quality of the mesh? So far I have tried Mesh > Smooth/Swap which has made it better, but I don't really know what I'm doing. Thanks! Vinay94 likes this.

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February 15, 2015, 11:16		#2
Tanmay95 New Member Tanmay Inamdar Join Date: Jan 2015 Posts: 10 Rep Power: 11	It will be better if you can do it in your mesher.Using a finer mesh helps.

February 17, 2015, 02:22		#5
maverick123 Member Join Date: Nov 2014 Posts: 31 Rep Power: 11	Hi, While launching Fluent standalone (not through WB) you can find toggle to launch in Meshing Mode.

February 17, 2015, 06:25		#6
ptstorey New Member Peter Storey Join Date: Oct 2014 Posts: 8 Rep Power: 11	Ah I see. I'm currently working in 2D, and meshing mode isn't an option when selecting 2D. Is there a way around this? Thanks

June 24, 2015, 08:54		#8
revilo82 New Member Join Date: May 2013 Posts: 7 Rep Power: 12	I think the ortho quality (>0.1) is ok for CFD and Adjoint. After some optimization loops not only the mesh changed but the flow situation, too. That (could be) the reason for convergence issues. The question is, how does the "solution is struggling to converge"? Does it diverge, oscillate, do you see some instabilities, slow convergence, ... ?

August 3, 2015, 12:57		#9
prafulla145 New Member Join Date: Jan 2015 Posts: 2 Rep Power: 0	orthogonal quality close to 1 is good, first try with default max face area, max and min sizing setting.If not then with trial and error obtain orthogonal quality close to 1. Orthogonal quality less than 0.001 is very poor.