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Old 07-31-2020, 10:38 AM   #287 (permalink)
aerohead
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what are these

Quote:
Originally Posted by veloman View Post
I'm starting to mod my gen 3 and wondering what these plastic things are in front of the front wheels? Looks like unnecessary drag.
As eco generator commented, they trip the flow.
The face of the tire is descending vertically, at the same velocity of the vehicle's forward motion, and the air, essentially acts like it's striking a waterfall.
The hour-glass body void, for wheel-flop cannot support airflow. It's a pretty serious mutilation.
The 'taco' fairings ( as Goro Tamai of MIT refers to them) help cause the air to deflect away from the face of the tires, as well as 'jump' the hollow void of the wheelhouse, then re-attach to the underside, once beyond the void. It's not as clean as streamlining the wheels and suspension, but it's way out ahead of nothing.
The solution is demonstrated with the Cd 0.189 VW XL1 and it's 'canoe' fairings. With very tight clearances, these types of fairings can reduce the total wheel drag contribution by 70% or so. The Cambridge University CUER eco racer demonstrates an ideal a example of the technology. Cd 0.11!
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