[frossi]

Hi,

I am studying flow past an inclined metal bar on a CFX 2D simulation. I created small elements around the bar and in the wake zone;
then, I added 20 inflation layers, but as you can see, when element quality is on, the quality of the inflation laters is really bad (red around the corners).

Question 1. Should I delete the inflation layers? Another approach I tried is: delete the inflation layers and decrease element size, like in the last picture. Which of the two approaches is better?

Also, because it's a 2D simulation, I followed the documentation and extruded the geometry about the thickness of one element. But I noticed that the quality of the element depends on the thickness of the extrusion! In fact, with a very small thickness I get a bad quality, but if I increase the thickness, the quality improves.

Question 2. Does the thickness of the extrusion matter? Or it's not important because it is a 2D simulation?

Question 3. Are inflation layers strictly necessary when doing fluid flows problems? Or I can replace them with small elements of good quality?

Question 4. Before I believed that with smaller elements I can obtain better results. Is this always true, even when the quality of the small elements is bad?

Please let me know. Thank you.