Yplus value

[sas2400038]

Hello

 

I am conducting an external aerodynamic analysis on a geometry characterized by a specific length and diameter. My goal is to capture transient/viscous effects accurately by achieving a wall Yplus approx 1 using the SST (k-omega) turbulence model.

 

I have calculated my initial cell height using a standard Yplus calculator based on my reference length, diameter, and freestream velocity. However, my current meshing attempts are exceeding my hardware limits, resulting in a massive cell count and extreme computational times.

 

Is it fundamentally possible to achieve a Yplus near 1 on the body while keeping the absolute total volume mesh (total cells) count under 3 million cells? If so, what are the best practices in the Fluent Watertight Geometry workflow.

 

Thank you for your guidance

[Anilkumar]

Hi,

Thank you for reaching out to Ansys Forum Support.

May I know what is the current hardware configuration you are using to generate the mesh? Generally we recommend having 3-5GB of RAM per million of mesh for very effective and faster meshing turnaround time with at least 6-8 cores for your 3M mesh expectations. It is difficult to say if we can get the mesh within 3M count without knowing the geometric details. Since, you can definitely create a coarse mesh on the surface and volume by enabling large minimum and Max mesh sizes and capturing the geometric details in coarser way, however if you are making it too coarse which leades to very high aspect ratio meshes and very large volumetric transitions then the mesh might not be suitable to give you accurate results. So, you might need to trade off between the mesh count and geometry capturing with smooth transitions to get the optimum solutions.

Hope this will help you to reconsider your meshing approach.

Thanks and best regards,

Anil