Ansys Meshing – Fine Mesh

A finer mesh gives a more accurate answer only up to a point, and the way to find that point is a mesh independence study rather than intuition.

The procedure is simple: run the case, refine the mesh in a controlled way, and compare a quantity you care about such as drag, pressure drop or outlet temperature. When that number stops changing as the mesh gets finer, you have a mesh independent solution and refining further only costs time.

Where you put the cells matters more than how many you use. Doubling the cell count in the far field changes nothing, while the same cells spent on the boundary layer or the wake can change the result entirely. The first layer height in particular should follow your turbulence model, and the Y+ calculator gives you that number.