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Old 03-24-2012, 04:10 PM   #11 (permalink)
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Quote:
Originally Posted by flying kurmaster View Post
just a thought, if you had a visor with a frontal leading edge with the same diameter as the Texas tech study 5 and something and brought it back in a tear drop shape and sloped it downwards securing it at the point of the tear drop to the roof from the side with rounded or wing shaped brakcets.!! capped on the edges like an airplane wing.
I would still be inclined never to vent it.
Much drag on road vehicles is generated where two airstreams of different velocity are attempting to merge and blend together.
If you've ever stood on the bank of a river where a smaller tributary stream discharges in you may have noticed a degree of turbulence where the faster flowing stream meets the slower moving river.This turbulence can extend for quite a distance downstream until the viscous shearing of the water dissipates the kinetic energy of the turbulence,converting it to heat.
I think that if you were to vent the visor that you'd be setting up exactly the same scenario,where a jet from the visor would collide with the flow along the sides,whipping it up into eddies,then full-blown turbulence.
Dr.Alberto Morelli spent untold hours in Pininfarina's wind tunnel attempting to kill this sort of thing with engine bay air bleeding into the banana cars outer flow.
I would follow Dr. MacCready's lead and just close it off altogether.This sort of thing would require a full-scale wind tunnel to perfect.
In 1990 when I went by Lockheed Marrietta,Georgia,the going rate was around $2,000/hour for tunnel time.If you could get in between NASCAR teams.The A2 facility which bondo has utilized could serve you at lower cost. It would require something like this to refine the visor.
PS if you were to experiment with the winglet atop the radius you'd be into countless hours with that as well.


Last edited by aerohead; 03-24-2012 at 04:13 PM.. Reason: PS
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Old 03-24-2012, 06:09 PM   #12 (permalink)
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^What he said.

I'm not a believer in "venting" for the purposes of lower aero in large part because internal ducts- faux or not- have their own drag. I also don't usually subscribe to protruding airfoils and vortex generators and such as being assets either- perhaps they can be made to help a bit after lots and lots of scientific refinement in a tunnel, but I see them as band-aids that aren't even attempting to cure the root of the problem, that being a flaw in the core shape.
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Old 03-24-2012, 06:36 PM   #13 (permalink)
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I can't believe I read the whole thing! [See below.]

The bottom line:

In an actual test, a truck as shown in FIG. 1 was extensively operated with and
without protrusions, and gas mileage records were kept. The truck was operated
at various speeds under 55 miles per hour, on a predetermined course that
required both stop and go city driving conditions as well as expressway driving
conditions. After protrusions… were added, it was found that fuel consumption
was reduced by about 17.2%


Search as I might on the Inter-web, I can't find anyone making aftermarket
pieces that closely resemble this idea.


Last edited by Rokeby; 03-25-2012 at 07:50 AM..
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Old 03-24-2012, 08:31 PM   #14 (permalink)
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Originally Posted by slowmover View Post
If we (the world) dropped patent protection and all other IP nonsense after five years we'd all be better off. Immeasurably so.

Thanks, Frank. Great thread idea. Just today linked a guy from another forum to this one in re a box truck he owns. As an architecture student maybe it'll pique his interest.
You might not feel that way if YOU had spent close to $40,000 and enough time to get a doctors degree.

Lets say you just work for me for free for the next 5 years (10,000 hours) and give me $40K of you life's savings.

That just covers the cost.

I think my patent is good for 17.5 years but requires a "service fee" for "maintenance" every 4 years or so.

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Old 03-26-2012, 01:33 PM   #15 (permalink)
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You might not feel that way if YOU had spent close to $40,000 and enough time to get a doctors degree.

Lets say you just work for me for free for the next 5 years (10,000 hours) and give me $40K of you life's savings.

That just covers the cost.

I think my patent is good for 17.5 years but requires a "service fee" for "maintenance" every 4 years or so.

regards
Mech
Patent protection, IP, and the rest is just a way of gate-keeping. Benefits a handful at the expense of the many. No one in our society or others does what they do alone, the contributions of others (hell, of nature) stand underneath it.

The current system not only doesn't work (as your post indicates), its' turned into a method (long ago) to stifle competition, not promote it. Like every system or institution, the corruption is so deep as to go past all efforts of reform.

I'm in favor, as is everyone, of seeing a return on effort. But what we have is more problem than solution. A clean slate would be best. Simple and short.

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