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Old 10-11-2012, 06:41 PM   #450 (permalink)
Cd
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Quote:
Originally Posted by Sven7 View Post
^^That's sweet.

Here's an example of flow detachment on the roof. Despite many ignorant threads asking again and again how to "fix" their roof forms, you can see here that it takes quite a lot to trip the airflow.

The blue one on top is stock (0.44Cd) and the orange camper is the (main) detached one (0.51Cd). Without even considering frontal area the camper shows much higher drag due to detached roof flow.

Look at that windshield to roof angle! And yet the stock one maintains attached airflow.



And a reason to remove that roof rack fairing.

Now that's interesting ! Despite adding frontal area, the rounded camper on the black and white van dropped from a stock - attached flow - Cd of .44 , to .40.
Overall drag in this case rose due to the massive hit in frontal area, but on our previous discussions on adding a tear drop roof to a boxy SUV, a much slimmer roof extention was imagined.
With so many SUVs having roof racks, it would be very easy to test - just take a thin sheet of wood and attach it to the roof rack, tapering it back .
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