[tomson199]

Hello,
I consider a problem with Aspect Ratio in mesh. CFX Modeling Guide says that: Aspect Ratio in single precision should be below 100, on double precision should be below 1000. But if I make grid in TurboGrid, for good resolve boundry layer I have to build a very thin element in every wall, and TurboGrid create high Aspect Ratio cell in freestream flow if i use tip clearence gap too, above 200 sometimes. Could you tell me is this mesh is acceptable for good computations flow? I obtain a very good residual convergance, below 1e-5 RMS. Next for comparing this contemplation, I created a convergence-divergence canal with two cases show in photo, and I receive this same results with good convergance of residual in both cases. In turbine blade, and in canal, I've got Expansion Mesh factor below 5 and Orthogonal Quality above 0.5. Do you think that for CFX Aspect Ratio is secondary factor for good flow modeling, and we should focus more on Orthogonal Quality and Expansion Mesh Factor? What do you think?

[tomson199]

Could anybody answer to me?

[tomson199]

Nobody wants answer to me?

[Far]

http://www.cfd-online.com/Forums/cfx...h-quality.html

In turbine blade, and in canal, I've got Expansion Mesh factor below 5 and Orthogonal Quality above 0.5. Do you think that for CFX Aspect Ratio is secondary factor for good flow modeling, and we should focus more on Orthogonal Quality and Expansion Mesh Factor? What do you think?

Thats correct... But keep in mind mesh quality metrics in ICEM CFD are more strict than required by any solver.

Same is true for CFX, which is general purpose solver. This is done in order to avoid the unexpected problems in solution accuracy and convergence for any type of mesh and / or flow physics.

[tomson199]

Thanks a lot