Turbolent model at stall

Molokovellocet

Hello to everybody! I'm a newbie with fluent and I will try to track Cl-alpha curve for the section of a bridge that isn't properly an aerodynamic airfoil but I have to do it for my thesis. I have read over 100 articles on this forum and I've found them very interesting and helpfull. But I haven't found something about my problem. I have modeled a incomprimible flow with a k-epsilon viscous model ( enahanced wall treatment active) and segregated solution. The problem is that after 6°, the solution don't convergence and is show the "famous" "turbulent viscosity limited to viscosity ratio of 1.000000e+005 in xxxx cells". I've tried to refine mesh with about 57000 cells and 58000 knot.How can I do???Many thanks to everybody