Jump in Cell Size when Growth Rate > 1.1 (2D structured Mesh)
 

Hello everyone,

I want to simulate a 2D airfoil using a structured C-mesh similar to this one: https://www.cfd-online.com/W/images/...mesh_final.JPG. Therefore I made a couple of sizings with a fixed number of divisions and a Multizone Quad/Tri Method. Overall the mesh looks correct, but in the area close to the airfoil the growth rate of the cells is strange as shown in this image:

https://imgur.com/a/1qwEq9r

I found out that it has to do with the growth rate of the sizing orthogonal to the surface (actually boundary, since it's 2D) of the airfoil. If I set it to 1.1 it looks fine:

https://imgur.com/a/kBvNjKI

The threshold seems to be around 1.11.
What am I doing wrong?

Don't use links to external websites for showing images. I won't open them.

Open this page on cfd-online to learn how to post images
https://www.cfd-online.com/Wiki/Ansy...n_the_forum.3F

Let me give you some more info. I guess my initial post was a bit too brief.


These are the sizings with bias:
Attachment 92978
red:
Attachment 92979
blue:
Attachment 92980
All edges have sizings. The ones without Bias have a fixed number of divisions similar to this:
Attachment 92981
The Multizone Method looks like this:
Attachment 92982