Learning Forum

[sas2400038]

Hi everyone

I am currently doing an external aerodynamics simulation in ANSYS Meshing and have a few questions regarding mesh quality metrics, specifically the aspect ratio.After generating my initial mesh, my maximum aspect ratio is around 700. I am concerned that this value is too high and might lead to convergence issues or numerical diffusion in Fluent.

I would appreciate some guidance on the following: Acceptable Limits: For a external aerodynamics case, what is considered an acceptable maximum aspect ratio?

What is considered a "good" target value.

Defeating High Aspect Ratios:

 What are the best strategies or settings in ANSYS Meshing to reduce this peak aspect ratio while maintaining strict aerodynamic accuracy?

 

Thank you for your advice 

 

[Essence]

Hello,

Most probably, the high aspect ratio cells will be found at the inflation layers (first few cells from wall) in the cases of external aerodynamics. May I know what is the y+ value you have incorporated?

[sas2400038]

Hello,

 

Thank you for your comment.

Since I am finalizing this for the report and want to ensure it strictly meets Ansys expert standards, could you let me know if you find the following metrics acceptable?

•  The y⁺ value across the vast majority of the aerodynamic surfaces is strictly between 0.3 and 1.4. A localized maximum y⁺ of 3.58 occurs only at sharp geometric edges.
• The maximum aspect ratio is 700, as i  mentioned (also total cell count is 3 million)
•  The minimum orthogonal quality is 0.11 

Given that these parameters align with standard external aerodynamics setups, do you think these metrics are good to go for the final expert review, or is there anything you would recommend tweaking?

 

Thank you for your answer

 

Best regard

[Essence]

We have seen aspect ratio going above 700 for external aerodynamics for many cases and the results still being acceptable. Please use CASM if you are using DBNS in Methods section.

Try to run the case once. You will then observe if there are any bottlenecks.

[sas2400038]

 

Hi so I checked 

And wanted to say thay the maximum aspect ratio is indeed 700 only in 10 places 

But the global aspect ratio is 46 which good and also the  simulation converged and results seems  good 

 

So my qeustion is

Is my simulation results worthy enough for a my report which will be reviewed by aerodynamics experts???