Reply To: Low drag coefficient for sphere

[Essence]

Yes, definitely. If not hexaherdal, polyhedra mesh provides superior accuracy and stability while simulating the case compared to tetrahedral. You might need to use Fluent meshing which is suited for Fluent solver. Please refer Ansys guide for more information on Fluent meshing. I hope this will prevent the convergence issues while using k-w SST and coupled solver. Please maintain minimum orthogonal quality more than 0.15 and overall growth rate in entire domain less than 1.2. Watch out for the flow separation on cylinder surface. Use Intermittent transition model if required. Most importantly, be careful of the reference values you input, since these values are directly used for calculating drag coefficient.