Quote:
Originally Posted by aerohead
I believe that the smoke is the more accurate indicator of the flow.
The air should detach right at the window trim and then crash against the rear of the car so as to allow the engine to harvest it for cooling.
Once the tangent angle on the roofline exceeds 22-degrees(as measured against the horizon)the flow cannot remain attached.
Attached-vortices can hold the tufts against the body but it;s a 'false-signal' when reading only the tufts.
Smoke is the preferred visualization tool.
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Hi Aerohead,
Sorry, I have to disagree with you. The air does not "crash against the rear of the car".
The air normally detaches at the top of the rear decklid, creating a low-pressure area behind it. Making it hard for the engine cooling fan to get air.
Volkswagen added more and more vents in the rear decklid trying to fight this.
I don't think wool tufts give a false signal. It precisely tells what's going on. Without the spoiler the airflow is still attached to the body, with the spoiler the tufts tell that there is turbulence behind the spoiler.
Greetings,
Gerrelt.