raymond%europa@uunet.UU.NET (Raymond Man) (07/28/90)
From: raymond%europa@uunet.UU.NET (Raymond Man) In <1990Jul25.004935.7662@cbnews.att.com>William Carroll discussed areodynamics of WIG vehicle. The effect ot a jet tending to attach to a surface is called the coanda effect, after the Italian Henri Coanda, who BTW was the designer of the first vector thrust aeroplane, which has the engine (and prop) tilted to change the thrust line and was burnt down because the hot exhaust lit up the fabric of the fuselage when the hot jet stayed on the surface due to, of course, the coanda effect. The WIG mainly reduces the induce drag on the wing, which sees a mirror image of itself giving out tip vortices or the opposite sense. In simpler terms, since the lower surface pressure is higher than the upper, leakage to the top occurs aroung the wing tip generating a tip vortex which accounts for the lost of energy due to lift induced drag. The closer is the wing to the ground, the smaller the area for such leakage flow and the weaker is the vortex. So a WIG vehicle can use a structurally efficient stubby wing without the penalty of large induced drag due to a low effective aspect ratio. Just call me `Man'. "And why take ye thought for " -- Matt. 6:28 raymond@jupiter.ame.arizona.edu