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Originally Posted by aerohead
I know that what they promote is implied in the animation.I'm not sure that what actually happens is in agreement with the facts.
Details such as this would require a 'full-scale',full Navier-Stokes equation, numerical analysis,which currently requires about 2-days run time on a supercomputer.
Again,Hucho ran the Volkswagen full-scale climatic wind tunnel for 10-years,and he tested these sorts of things.He never saw anything lower drag ,except for box-cavities and boat tails.
I'm not calling Air-Tabs a 'liar',but I'd want a more rigorous investigation.
They haven't altered the frontal area,nor pressure at the separation line.I'd like an explanation for how they achieve a higher base pressure without some sort of reversed step.
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We did some testing of Air-tabs on a 35 foot travel trailer using an aircraft engine blowing air down the side of the trailer and both tufts and smoke. Without the airtabs the tufts or ribbons just snapped around everywhere, tying themselves in knots behind the trailer, and the smoke curled tightly around behind the trailer. With the airtabs about 6 inches from the back of the trailer the tufts/ribbons stood straight out behind the trailer with virtually no flapping, and the smoke went back about 15 feet before starting to swirl. Wind speed was in excess of 60MPH down the side of the trailer. (about 12 feet? from a wall) I'd say they do pretty much what the information from airtabs claims they do. They sure keep the back of the trailer clean.