bjbear wrote:
At this point, I am thinking that dampening the Bernoulli effect might have more of an effect than the displacement of air to the sides (like your barge analogy). Although displacing the air sideways also reduces the air volume and therefore velocity!
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I am going to work this some more, but for now, I will hold off on installing my air tabs until I understand the physics a little better. :? Where is Sheldon Cooper when I need him!! :D
You might want to actually test that hypothesis. It would not be that difficult, using an Air
speed Indicator and a primitive pitot. Lacking an ASI, you could make one (manometer type) out of a clear plastic tube and some water. The dynamic pressure at 55 mph is around 7.8 psi, at 60 it is 9.2, a 1.4 lb difference. That would give you around 2.3 feet difference in your water column - pretty easy to see. The interior of the cab is probably a good enough static source.
If you are right, then the air tabs might be working just by slowing the air. Adding a lot of vorticity is going to make the boundary layer very thick, once it is half the thickness of the gap then the hypothesized jet of air ceases - or at least is substantially reduced.
