Quote:
Originally Posted by California98Civic
There really is more for you to learn from foundational research about lift and drag, but you routinely just dismiss all of it. "Replicate the relatively rough surface of a car" is not not the path to lowest drag and lift. It is the path left available by an automotive industry, regulatory regime, and consumer market that makes more "ideal shapes" not practical on the road.
|
I am comparing the relatively rough surface of a car with the surgically smooth surface of an aerofoil.
No production car will ever have such a smooth surface, as the production costs would be too high for a mass-produced item.
As surface roughness increases, so does the thickness of the boundary layer. The thicker the boundary layer, the more likely flow separation will occur. When flow separation occurs, the airflow is no longer following the shape.
Therefore, the surface roughness of a car needs to be considered when assessing 'ideal' shapes.
An 'ideal' shape that implicitly assumes a very thin boundary layer (as aerofoils are modelled to) has grave shortcomings when applied to a car.