Quote:
Originally Posted by Cd
Does anyone here have access to a Mercedes A class sedan ?
The car has an excellent .22 Cd, yet not only deviates from the template, but also has a short trunk / boot that you would think would keep flow from reattaching.
I seemed to recall it having quite a bit of tumblehome to the rear, and thought this maybe what helps the flow reattach, but after looking at one that my neighbpr has, I see that is not really such a big factor.
The reason I am asking is to see if someone would be willing to do a tuft test at the rear of the car to show what happens with the airflow. *
The .25 Cd LS-430 had an even steeper back window, but it has a longer trunk / boot that could help the air to reattach.
* or some CFD images of the rear of the car.
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* Tufts will not necessarily allow an observer to easily distinguish between 'attached' flow and 'downwash,' whereas smoke will.
* The 'template' really shines with sub-Cd 0.15 vehicles, so Cd 0.22 is kind of a walk in the park by comparison, and doable with a notchback if the rear roof, C, or D-pillars, boot height, boot length, separation bubbles, and spoilers are all tuned to a symbiotic optimum.