Quote:
Originally Posted by Xist
I was going to write my notes. I swear! I just saw a response to the boat tail video.
I replied to it and was about to write my notes.
But wait! Except, they aren't dimples, they are outies, and they aren't on the entire car, they are on a roof scoop, which feeds the 8-liter engine.
They aren't normal outies, either, they are active, because they are supposed to hurt aerodynamics below 50 MPH, so they automatically extend above that--on a race car, which is supposed to hit 60 MPH in a couple of seconds, so it would only matter for 2.
Also, none of this was tested, it was all simulated on computers.
The annoying guy in the video ridiculed it.
Someone in the comments led me to this video:
He is holding the model car on which they tested dimples before they went full-scale.
"It's [...] not really a scientific methodological approach that i would approve."
The automaker tested a full-size model, not on a one-mile track, but in a wind tunnel.
I really feel that if we knew about this when it happened we could say there is nothing else to discuss.
I just wish that I knew what they did find. |
The only conclusion I could take way from the dimple experiment was that, on the Ford, above the backlight, and down the C-pillars, they functioned as vortex generators ( VGs ), and drew the flow down and in a bit, allowing reattachment, or enhanced reattachment onto the boot, before finally separating.
At the enhanced upper rear separation line, the static pressure would be increased, raising the base pressure of the wake, lowering pressure drag, and lowering overall drag.
The 'OEM' super-critical Reynolds number would have taken care of the rest of the car.
Had they only applied VGs to the roof, as with the Mitsubishi LANCER EVO, it's highly likely that they'd have seen similar results, without all the dimples.