Convergence not with all turbulence modells
 

Hi!

I'm pretty new to fluent. I made by now some aerodynamic symulations of some airfoils. I do my hexa mesh in ICEM. When I have only one airfoil i don't have problems to achieve convergence, but now I'm doing some more complicated shapes (like two airfoils).

I have a question. What does it mean when I can not achieve convergence with one turbulence model (Kepsilon reliazable non equlibrium wall function) because of sinusoidal behaviour of CL during computing. But I'm able to achieve nice convergence with SA model. What does it mean? Bad quality of mesh? I paste ale some pict of my mesh.

Hi,

1) If you don't get convergence with one model did you try to change the solution methods? Sometimes it's just a solver's problem.
2) What about your y+ on the airfoil?
3) You have some "jumps" in cell sizes in your mesh and also some strong angles. You could try to enhance your mesh by smoothing in ICEM.