Quote:
Originally Posted by euromodder
Looking at the angles of the roof, it doesn't need any dimpling for aero purposes.
Where the design might use them - like aft of the rear wheel arcs, where the bodywork falls of sharply - there are no dimples.
You don't want round shapes on the rear.
|
The thing that drives me a bit crazy is this whole dimpling thing. Golf balls have dimples because they are so small compared to the viscosity of the air. Very small dimples the size of the ones in golf balls might work on a small scale but not with golf ball size divots on automobiles, etc. Vortex generators work by creating low pressure areas and suck down the thick boundary layer to follow the profile. The more you work the air the more drag is produced. Sometimes it's on the positive side when detached flow is resolved.
Rounded in front with smooth pressure recovery profile in the rear. Most things are compromises for shape and space with true streamlining rare. Don't look at Racecars since they are more about down-force than pure drag reduction.
Reynolds numbers are the reason that aerodynamics is so different on the micro vs. the macro scale. Also there is a great deal of difference on what works aerodynamically at 0-100, 100-250 and 250 MPH up to near Mach speeds. There is a huge body of information out there.