Milne Ando

The mesh of the CV is quite good; the orthogonal quality of all cells is over 0.3. Face sizing is set to be 0.8 mm and used on the "Fluid-Solid wall". Inflation surrounds the "Fluid-solid wall" with a growth rate of 1.2, first layer height of 0.09 mm, and Maximum layers of 12. The transition between inflation and outer cells looks great as the pic shows. The element Size is 16.0 mm with a Max size of 24.0 mm.

Oh, I don't know that time step size is determined by cell height. Do you have an empirical formula for this?