[alw7]

Good Morning,

I am new to CFD and I am learning through STAR-CCM+. I am currently creating a trimmed mesh around a cylindrical geometry. I am trying to understand how to determine what the best surface growth rate would be in the default controls but I am not understanding how that number can be determined.

Thank you!

[AndreP]

Originally Posted by alw7

Good Morning,

I am new to CFD and I am learning through STAR-CCM+. I am currently creating a trimmed mesh around a cylindrical geometry. I am trying to understand how to determine what the best surface growth rate would be in the default controls but I am not understanding how that number can be determined.

Thank you!

The Surface Growth Rate determines the MAXIMUM ratio of growth that one cell can have in relation of the connected cells.

So, imagine. If you have one cell close to the surface with 1mm size, and you have the Surface Growth of 1.3, the next cell will be AT MAXIMUM, 1.3mm! It can although happen that the mesher decides it needs to be 1.2mm ou even 1mm again! It only specifies and control how your mesh will grow away from the Surface.

I don't think there's a mathematical calculation for this. Is one of the parameters that you'll tweaking and reducing, to achieve a better mesh quality and stable results, if needed!

[me3840]

If you are making a trimmed mesh then the surface growth rate is largely irrelevant. Trimmed meshes can only grow and shrink in factors of 2. The surface growth rate will only really affect the mesh in areas of high curvature, which you will have to refine with the trimmer anyway.