Reply To: Low drag coefficient for sphere

[Zayn Zai]

Hi Essence, thanks for your reply.  I reduced the inflation cell height and added more layers, which resulted in a Y+ value of 1.03. However, despite these changes, the drag coefficient I obtained was 0.32, which was lower than the experimental result of 0.45. I attempted using the SST k-w turbulence model as recommended by my research, but encountered convergence issues when employing the coupled method. Switching to the SIMPLEC method resolved the convergence issue, but the drag coefficient remained low. As for why I'm using tetrahedral mesh, It is because I have read somewhere that tetrahedral are more suitable for curve surfaces which in this case is the surface of the sphere. Does using polyhedral or hexahedral meshes could improve accuracy?  I'm relatively new to Fluent, I lack the expertise to determine the optimal mesh type for my simulation.