Lexus debuts dimpled LS 460 L for U.S. Open
Golf ball dimpled Lexus LS 460 L – Click above for high-res image gallery
Now that Tiger Woods is no longer shilling for Buick, the opportunity for another automaker to enter the golf world and attract some eyeballs is wide open. Lexus is a sponsor of the U.S. Open that just teed off this week, and to make sure its participation is remembered, the Japanese automaker commissioned the production of an LS 460 L with a dimpled body just like a golf ball.
The creation of this oddity is actually an interesting story. At the PGA Golf Show in Orlando, FL last January, Lexus approached Brad Smith of Lima, OH who earns a living making those mailboxes shaped liked giant golf balls. After being asked by Lexus if he could put the same surface on a car, Smith approached his friend Rick Davis and together they found a composite polymer that would work. The two buddies built the car in Davis' two-car garage, though Lexus likes to refer to their operation as the "firm" responsible for the car's creation. Lexus took delivery of the dimpled LS last week right before it made its debut at the U.S. Open in New York on Tuesday. Dimples help you drive a golf ball farther, faster and with more control. Do you they do the same for the Lexus? Perhaps Tiger Woods should get behind the wheel and find out.
Photos courtesy of Gavin Jackson and The Lima News
Gallery: Golf ball dimpled Lexus LS 460 L
[Source: LimaOhio.com via Kicking Tires]
Reader Comments (Page 1 of 2)
policyvote 6:23PM (6/18/2009)
Okay, find two identical Lexi and wrap one in that dimpled plastic wrap! Then, do a Mythbusters-style MPG marathon. That would settle this all once and for all.
Peace
policy
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thomas 9:25PM (6/18/2009)
thats funny.
Scott K. 3:37PM (6/18/2009)
Anyone else get reminded of that Fastskinz car covering that claimed to increase gas mileage?
http://www.popularmechanics.com/automotive/new_cars/4316702.html
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pmalloy4391 3:51PM (6/18/2009)
I was thinkin the same thing...
paul34 4:18PM (6/18/2009)
Yea, exactly. Also, didn't Autoblog test it, as well? Or was that TTAC? Can't remember. But someone did.
Oh wait, I think it was popular science. Maybe?
ccdoggy 7:45PM (6/18/2009)
If done properly it should increase mileage and decrease drag on the vehicle. the dimples create pockets of air as if its almost a cushion against the on coming air. mind you the decrease in drag is really not that great but it is still something.
it causes less friction to have the oncoming air be diverted by the pocket of air then flat metal.
paul34 7:26PM (6/18/2009)
Danget I'm stupid. You linked the article right there at Popular Mechanics. Anyway, I think Autoblog reported on that PM article a few months back.
simonlu 8:44AM (6/19/2009)
ccdoggy:
...A better explanation than "cushions of air" might be:
Air is viscous, however, viscous effects are only significant in a thin layer very close to the surface, called the "boundary layer."
There are two types of flow in the boundary layer: laminar and turbulent (the names are telling, and a quick Google image search will show that the visual difference is very obvious between the two). Generally, the flow on a panel begins laminar, and transitions to turbulent, the location of transition depending on a nondimensional parameter called the Reynolds number (Wiki for more info).
There are two primary forms of drag cause by viscosity: skin friction and flow "separation" (wiki it) the former called skin friction drag, the latter most often termed "form drag" or "profile drag" or "pressure drag."
Skin friction drag is higher for turbulent flow than for laminar flow. However, it is harder for turbulent flow to separate from the body, so profile drag for turbulent flow is generally lower than for laminar flow.
In the case of blunt bodies (golf balls) with fairly extreme surface curvature, flow separation is the biggest drag problem, while for streamlined bodies (say, an airplane wing at low angle of attack), skin friction drag is the biggest drag problem.
Hence, for a blunt body like a golf ball, it is best to trip turbulent flow as early as possible. The dimples add "roughness" to the golf ball surface, and hence help to trip turbulent flow, aiding in flow attachment and profile drag reduction.
For a fairly streamlined body like a Lexus LS (and I'm sure they design it to be so), dimples may unnecessarily increase skin friction drag (i.e., it'd be like attaching blocks of sandpaper to your car).
Jared 10:23AM (6/19/2009)
I just wana know how they made the dimples, and how long it took them to do the whole car.
jaartsgroup 3:40PM (6/18/2009)
wow.
i'd actually love to know how this affects aerodynamics. wool tuft and wind-tunnel time....
awesome.
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artandcolour 3:52PM (6/18/2009)
i like it! very creative, and an interesting alternative finish. with matte finishes springing up here and there, i wonder it textured finishes might be around the corner? i could see a diamond-pattern like a Chanel handbag for the ladies to go along with the golf ball pattern....
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Joe K. 3:53PM (6/18/2009)
Just remember that the surface area of a golf ball does not hold a consistent face to the wind.
So for a proper test this car needs to be doing crazy amounts of donuts...
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happyfun86 3:56PM (6/18/2009)
Dimples help a golf ball because the ball is spinning. All the dimples would do on this car is help it roll down a hill faster.
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TigerMil 3:57PM (6/18/2009)
2nd. I read somewhere that someone actually tested dimples on a car for aero.
sitruc 3:56PM (6/18/2009)
Without reading the full headline or the articles, I assumed it was a test vehicle with materials on it so it would fool cameras.
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Andy 3:58PM (6/18/2009)
I'm impressed. This is harder to do than than people think.
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thomas 9:21PM (6/18/2009)
i know.
Markus 4:00PM (6/18/2009)
I'm neither a golfer nor a car designer, but I guess the point of the dimples on the golf ball are to prevent "fluttering" of the ball, i.e. alternating separation of the boundary layer. That happens because the ball is spherical. Furthermore, it rotates during flight. The solution is influencing the boundary layer everywhere on the surface, hence the dimples (I guess). A car on the other hand will (in most cases) not rotate while moving and have a defined forward and rear facing part :D, so you don't need the dimples, you just use a sharp edge (i.e. simple little "spoiler lip" on the trunk or at the end of the roof) to prevent moving separation zones/unwanted turbulence. Therefore, I'd say no dimples for my car, please.
Any golf ball or car designers on here to tell me if I'm right or wrong?
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thomas 9:23PM (6/18/2009)
yes, yes i can.
you are both right and wrong.
:-)
simonlu 11:15AM (6/19/2009)
Markus:
I rarely play golf and am not a car designer, though, judging by the student work that gets posted here every once in a while, I would think much of the aerodynamics is left to the engineers, not the "designers." I'm not sure what you mean by "alternating separation of the boundary layer." I agree the golf ball can have spin. First, assuming no or insignificant spin, due to radial symmetry of a spherical golf ball, boundary layer transition is the same regardless of your angle (i.e., every 2D slice looks the same). If the golf has side spin (i.e., spin colinear with the direction of flight), that shouldn't effect what you're concerned about. If it has topspin/backspin (i.e., spin orthogonal to the direction of flight), flow velocity in the frame fixed and rotating with the golfball, flow on top will be faster/slower than flow on the bottom, meaning turbulent transition will occur sooner/later on top than on the bottom. What does that do to drag? Don't think there will be much change in the net drag, but there will now be a moment on the ball due to drag, I can't tell you what direction that moment is in, it all depends on the balance between skin friction and how soon the boundary layer separates.
I think it is generally accepted that the reasoning behind dimples is to trip turbulent flow and to reduce flow separation at the expense of greater skin friction drag. This results in a net drag loss in the case of a bluff body like a golf ball, but a Lexus LS is hardly a bluff body.
Though I agree with your conclusion, and give a simpler reasoning: if dimpling actually did reduce drag on cars, everybody would already be doing it.