Aerodynamic...but not aircraft

On Wed, 16 Jul 2008 23:18:56 -0400, "Flash"
wrote:

Back in the 70's, the Univ of MD did a real great study of that sort of
thing. They determined that if you could eliminate the gap altogether, you
would have a MUCH better efficiency.

They had a system of complex levers and springs and stuff on moveable panels
that eliminated the gap on top and sides, right down to the road almost.

Try that on your pickiup and your wickiup. - NOT!

Really, if you can get as close to eliminating the gap as you can, the only
problem will be the sides. The top can be a piece with a concaved-shaped
edge on the truck, a convex-sort of sheet on the trailer, with the *center*
of the arc approximately over the hitch-point.

The OTR trucks have side-fairings on the cabs that are sometimes two feet in
length, but they work that way because the pivot of the fifth wheel is over
the axles, about 4 or 5 feet behind the front of the trailer. When the
trailer turns, the corner of the trailer is up between the fairings.

Really, just eliminate as much open distance as you can. If you had a "fifth
wheel" trailer, you'd be further ahead.

Flash

About anything will be better than the open bed dragging an 8x8 flat
plate.

--Andy Asberry--
------Texas-----