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Old 02-26-2012, 10:12 PM   #275 (permalink)
Frank Lee
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Quote:
Originally Posted by ChazInMT View Post
Something I notice, the air on the side is moving Up...I'd think we'd wanna do what ever it takes to keep the air moving in a straight line in relation to where it starts. If this is achieved then the air will end up where it started before going around the shape and this will accomplish the best result. If the air is moving up, then it will meet the air coming from the top and create the swirl (AKA Vortex). I don't know what it will take to balance this out.
You want the air to be displaced the minimum amount. If the form is tall and narrow (like a vertical airfoil) the displacement is least by shoving the air laterally. If the form is short and wide (like a Countach) the displacement is least by shoving the air more vertical than lateral. If the form is about the same height and width then a displacement vector of about 45 degrees up and out (as shown) would be optimal.

The air is going to pretty much figure out where to go for the least displacement around any particular form. It's up to us to provide nice slippery forms. I think that since crabbing into x-winds is generally a solution with too many practical difficulties, the low+wide form has aero advantages over square and tall+narrow forms.
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