Surface represented incorrectly for NACA profile
 

Hello all

I am simulating flow over several Naca profiles. These have been drawn in Solidworks and saved as STEP files. I have this repeating problem for some of the profiles that looks odd at the leading edge (see figure) while the others don't.
I have imported the step file with the "very fine" option and I have a well-refined mesh.

The fin has the dimensions of:
- Chord length: 27 mm
- Width: 1.3

Mesh settings:
- Prism layer Thickness: 2.0E-4 m
- Prism layer number: 18
- Prism layer Stretching: 1.1
- Surface Curvature: 200
- Surface Growth Rate: 1.1
- Surface Proximity: 2 points in gap
- Template Growth Rate: Very slow

Do you have any suggestions on what I could try to improve the surface representation.

Hi,

my guess is that its coming from the mesh. Should be easy to check for you. If its not the mesh, check your CAD to make sure its really clean and valid at the trailing edge.

Surface Min Size, Surface Target Size?

I think you are correct, that the problem is caused by the mesh. I tried to alter the mesh in many different ways, and finally found that by choosing the following settings I can get a better (but not perfect) mesh:

Surface proximity = 100
Relative min size: 0.001 m
Relative target size: 0.004 m

The problem is now that all the surfaces in this region are refined, thus almost doubling the total number of cells for the simulation.
Is there any way I could lower these three values only for the surface of the NACA profile, but not for all the surfaces in the region?
I have tried to use the "Volumetric Controls" just over the wing, but it seems to only alter the volume mesh and not the surface mesh. Is that correct?

I managed to solve the problem by the use of volumetric controls.
Thanks for your inputs, cwl and SESP