[aerohead]

Fluid mechanics is so well understood that entire aircraft are designed numerically within a confidence of 2% as of around 2000.
If you want a good look at 'particles' I'd recommend a textbook and look at the section for submerged bodies in viscous flow.You should have at least a graduate level degree in mathematics.
For automotive work you'll need a super-computer and a fat wallet.After millions of dollars of CFD,automakers are still spending additional millions in the wind tunnel as a backup.