On Thu, 27 Mar 2008 00:57:43 -0600, cavelamb himself
wrote:

Ed Huntress wrote:
"cavelamb himself" wrote in message
...

William Wixon wrote:


"cavelamb himself" wrote in message
...



Well, get a great big wind tunnel? :^)

Or

Look at the inverted spoilers on the backs of SUVs and old station
wagons.





that's funny because i'm right in the middle of putting ladder racks on
my pick up truck cap. i have an piece of streamlined aluminum airplane
strut that i'm going to use for the horizontal. i was wondering if that
might kinda break the boundary layer. doubt it. hafta check with a wind
tunnel, which i have none.

b.w.

Yarn, about 6 inches long, taped all over teh surface can show what the
local boundry layer is doing.

Now, OBSERVING that effect might be a trick.

Need another truck and video camera to make it work,

Richard


This isn't very hard to do, once you get some practice. I taped yarn tufts
all over my racing ITC Fiesta (yeah, I know -- it wasn't much) in the
mid-80s and videotaped it from another car driving on an Interstate. I was
checking the effects of propping up the rear of the hood, which was legal in
SCCA's ITC class.

--
Ed Huntress



Yeahbut...

Watching the top of a semi trailer????

I'll pass...

Richard


In the US...there are many overpasses that clear trucks by less than
6"

And some that dont even do that....

http://graphics8.nytimes.com/images/...commute600.jpg


Gunner