Quote:
Originally Posted by aerohead
The drag coefficient will not stabilize until the body reaches a critical Reynolds number which forces transition to the turbulent boundary layer.
Reynolds number is a function of body length and velocity with road vehicles.
*For a full-scale vehicle the critical Rn will occur at 20 mph.
*For a 1/2-scale 40 mph.
*1/4-scale 80 mph
*1/5-scale 100 mph
*1/6-scale 120 mph.
Aerodynamicists use the term verisimilitude to describe the necessary relationship among scale-models with which to produce an Rn which will produce meaningful data.
freebeard just posted a link to Suzuka's wind tunnel work which covers this phenomena.
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Great information aerohead, thank you for your post.
Here is the link and quote to freebeard's post in the Air-Tabs thread:
http://ecomodder.com/forum/showthrea...r-25687-4.html
Quote:
Originally Posted by freebeard
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I suspect the SAE paper I posted (#
2012-01-0168) will cause me to abandon the
Part-C template all together.
I've only skimmed it, but so far it looks like the smaller the aft area of the car (as long as you have flow/attachment) is more important than maintaining the template arc at full scale.
This makes sense, but like I said I have to read the paper in full and do some test overlays to confirm.