NACA 4 digit simulation - not converging
 

I'm doing simulations on a NACA 2408 aerofoil, and at angles of attack of about 10degrees or greater it just won't converge, and normally the graph that shows when the solver is running falls into a periodic pattern. I've tried the simulation with various meshes (i.e. more elements in the mesh) and added layers to the inflation boundary around the aerofoil without luck. I've also tried to change from Auto timestep to physical timestep, trying a couple of values there but still no luck. I'm running SST turbulence, and it's a steady state simulation. I'm a complete novice with CFX and any tips on how to get it to converge would be much appreciated, thanks.

hi,

Have a look at:

http://www.cfd-online.com/Wiki/Ansys...gence_criteria

I bet it is going transient as you approach the stall point.

Glenn Horrocks

Thanks for that. Not really sure what I'm doing now but I'll see if I can get it to run as a transient simulation.