? about Golf ball dimples

[itjstagame]

Wow that's pretty cool, I'd be really curious to see placement on the vehicle and try to figure out what the VW guys were thinking.

Of course I'd also really like to see how ducting works. I'm not an engineer, so I can't 'solve' how good it'll work. It certainly 'seems' like it'd save the energy of the car 'crushing' the air and building pressure in front and underneathe and also using energy to 'suck' air back in to the void behind.

[dutchdivco]

Actually, that answers my question; they don't have to be the diameter they use on golf balls;they CAN big larger diameter. Thanks, All!! Jim

[theholycow]

My vague memory was accurate, they are about an inch in diameter and less than a quarter inch deep. That's amazing, usually my memory fails at everything.

The dimpled areas are flat (well, except for the dimples) surfaces on the undercarriage, mostly running along the sides, between the front and rear wheels, from the edge of the car to about 16 inches in.

I don't know why they used those dimples, I can't say for sure that they were for aerodynamic drag reduction (then again, what else could they be for?).

[dutchdivco]

Yeah, they say memories ,...either the first or last thing to go, but I can't remember which!,....You sayed it, What else COULD they be for? The ducting should work pretty well. Seems straightforward.The one thing I'm curious about; obviously at low to medium speed, the air in the front will flow to the back. As you increase speed, the "amount" of drag increases at a greater rate than the speed increase. I'm wondering if, at a certain point, the negative pressure will begin to move 'up' (actually forward) the duct.While I'm not counting on it by any means, I'll be on the lookout for a pulling or surging at say 60-65 m.p.h.Could happen, I don't know.;-)

[Jay2TheRescue]

Originally Posted by theholycow

I don't know why they used those dimples, I can't say for sure that they were for aerodynamic drag reduction (then again, what else could they be for?).

Just thinking out loud here, but it could be for structural reinforcement on those panels... A dimpled piece of plastic is less prone to flexion than a thin, flat sheet of plastic. Any aerodynamic benefit may be purely accidental.

-Jay

[theholycow]

I thought that, but how much less flex would dimples cause? Wouldn't it be more effective to use ribs? They are decently thick plastic and don't span very far (about 16" wide).

[Jay2TheRescue]

Yes, I agree ribs would work better, but right now we're trying to guess what a German engineer was thinking when he designed it. If the panels aren't that large then making them more aerodymanic would have very little, if any effect on the vehicle's economy as a whole.

-Jay

[GasSavers_SD26]

Originally Posted by Jay2TheRescue

Yes, I agree ribs would work better, but right now we're trying to guess what a German engineer was thinking when he designed it. If the panels aren't that large then making them more aerodymanic would have very little, if any effect on the vehicle's economy as a whole.

-Jay

Well, that begs the question...

One could make a couple other cases.

Big dimples could be used to reduce the amount or material in the covering while maintaining a web of structure for the piece. Might only be an accountant, a money engineer, that is doing any work on that piece beyond its initial value.

[Jay2TheRescue]

I can understand that... I ran into a similar problem a few years ago when remodeling a bathroom that was in a townhouse. I tried to put a smaller vanity in the bathroom to make it look like a larger room, but I found out that the builder didn't put tile under the vanity, and of course 20 years later you'll never find tile to match. I thought "Damn cheap builder..." It maybe would have cost the builder an extra $10 or $15 to tile the whole floor, but then I got to thinking... Saving 8 tiles in each bathroom * 3 bathrooms = 24 tiles per unit saved. 24 tiles * 150 townhouses in the neighborhood = 3,600 tiles the builder didn't have to buy. In each unit very little was saved, but overall across the entire production there was a signifigant savings.

-Jay

[theholycow]

Originally Posted by Jay2TheRescue

Saving 8 tiles in each bathroom * 3 bathrooms = 24 tiles per unit saved. 24 tiles * 150 townhouses in the neighborhood = 3,600 tiles the builder didn't have to buy. In each unit very little was saved, but overall across the entire production there was a signifigant savings.

Besides the cumulative cost savings on materials, the labor savings add up too. Not only is labor saved, but then everything is done just a little bit sooner, each trade can get in and out that much sooner, and payment comes sooner. Time is money.