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


"Too_Many_Tools" wrote in message
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On Mar 26, 11:41 pm, "Ed Huntress" wrote:

snip

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.

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Ed Huntress- Hide quoted text -

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Excellent idea.


TMT


It is not original. g Several good books on building racecars describe
it, and that's where I learned it.

--
Ed Huntress


What was the idea?

Vent off the high pressure area in front of the windshield?


Richard
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Oh, jeez, maybe I misunderstood what TMT was commenting about. I thought
he meant that the yarn tufts are a good idea. They are, but they're also
a very old idea.

Regarding propping the hood, the idea is to let hot air out from under
the hood. I know, the bottom of the windshield often is a high pressure
area, but it's another old idea. An ITC Fiesta didn't generate enough
extra heat that you had to worry about the overheating issue.

The reason I was trying it was to see if I could delay separation for a
couple of inches down the hatchback window. I know, it was unlikely to do
anything at that remote distance, but I was curious.

FWIW, the sharp edges on the Fiesta started turbulence every which way,
but then it re-attached. Over the top, it re-attached about halfway along
the roof, and then it promptly got turbulent again, before you got to the
rear window.

I also put closed-tube manometers (made from aquarium hose) at different
points around the car and tried *that*. The car was an aerodynamic mess.

--
Ed Huntress
Yeah.

Those were the days before turbulators became well known.

I don't know them so well today, for that matter. g I look at aerodynamics
texts today and my eyes roll back in my head.


People were still trying to push air around like it was a solid or
something. Won't work, of course.
Air is the only thing on this planet lazier than me.

But tickle the bottom of that turbulent flow and it will often lay right
down on the surface.

For that matter, so will I! But you probably don't want to know that.


Jeez. Here comes another OT thread. d8-)

--
Ed Huntress