1 | Very small length scales dL are present in "turbulent regions" maybe need to resolve a size |
2 | dL ~ 10-3L |
3 | If dL covered by 10 grid points then leads to 104 grid points in each linear dimension L which is impossible |
4 | So "average" over fine length scales (~10-3 cm) and write a new set of macroscopic equations. |