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Attention Racers: Amazing Aerodynamic Results

nucleus

Well Known Member
on Mythbusters recently, anyone catch it? You can here. They measured an 11% increased fuel economy at 65 MPH by putting giant golf ball dimples all over a Ford Taurus.

Here is a short clip of just the dimples on the car.

Hans
 
Re: Okay you first

I wonder what the density of modeling clay is? Half an inch of modeling clay on my cowling, test smooth and then dimpled per their example. Probably throw put the cg forward too far. With all the disturbed flow around the cowling I could see 1 inch dimples making a difference.

Hans
 
Just park your plane in front of a driving range, and turn once a day.



Okay, maybe not such a good idea.
 
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having not watched the video....

I thought the dimples created little vortices and therefore a boundary layer, allowing a more aerodynamic shape (of boundry layer), making the golf ball fly farther.

It works because it is not an airfoil.

The Taurus is probably not the most aerodynamic vehicle, so adding dimples should work.


These RVs require a lot of dimpling, So it only makes sense they fly fast. :D
 
So now....tank blisters

are a good thing?????????????

Not so fast moosebreath!!!!!!!!!!!!!!!!!!!!!!!!!!
 
FWIW....

Ten years ago, a local friend bought a hail-damaged Skyhawk on the panhandle of Florida. We went down in his other non damaged Skyhawk to pick it up and it was significantly faster with thousands of small dents all over it.

Regards,
 
Ten years ago, a local friend bought a hail-damaged Skyhawk on the panhandle of Florida. We went down in his other non damaged Skyhawk to pick it up and it was significantly faster with thousands of small dents all over it.

Regards,


I do not buy it, Pierre. There was other reasons for it to be faster. (Maybe it looked so bad the other Skyhawk wanted it out of sight so let it run out ahead)

Dimples, vortex generators, riblets, etc are fixes to problems and not part of good aerodynamic design. balls and current car shapes are not good aerodynamic design. Balls are designed to roll; cars are designed to look good (and keep you alive in a crash).

I do love the Mythbuster guys, though.
 
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porsche was done too

A Canandian science show "Daily Planet" did a story on a group who wrapped a Porsche with dimpled vinyl and it showed an improvement in top speed as well
 
I put Dimple tape on the thickest part of the wing of a large RV4 RC airplane (72 in span) and it definitely lowered stall speed and improved slow flight performance. I can not tell if affected top speed. The tape is about 0.015 thick and 1 inch wide and has holes cut in it like a golf ball. I'd like to get some more but can not find a source any longer.
 
sailplane trick

In the sailplane world, most modern sailplanes have a strip of tape to trip the laminar flow to reduce drag. RVs can benefit from the same trick, if there is a laminar flow to turbulance flow transition. There is a whole science behind this. Most of it starts with using oil smeared on the plane to figure out where the high drag areas are and then adding this small tape to trip it airflow. this greatly reduces boundary layer drag. I started looking at this for race cars before my career turned again.

Johnny stick
RV10 wannebe
 
Wash this

Odd that the show acted like they had discovered something "new" and didn't mention, at all, the massive amount of R&D that has occured on this very subject over the years. The benefit of skin drag manipulation is so commonly known, hasn't it use has been banned from most forms of speed racing ? I considered this episode to a nicely done demonstration of an already widely known behavior of fluid dynamics. The next step should have been to then streamline the car and compare the streamlinings effect on boundry layer seperation and mpg, to the dimpled, and the 'normal' car. I notice that auto mfgs choose streamling, the prius for example, over 'turbulent boundry layer devices' for the newest high mpg cars. I guess that at the end of the day this show is about "Mythbusting" and not about "Teaching Science and Engineering". Just think about the effort of washing all of those dimples on your shiny new silver golf ball of a car :rolleyes:
 
So who is going to be the first volunteer to dent 100,000 dimples onto every square inch of the skins on their RV?

Hey, if it works you can sell your design to Boeing and be the next billionaire
 
Actually, I think there already is one in Fredricksburg, Tx. Seems like I saw a picture here a few years ago.

Tracy.
 
My car was perfectly dimpled by mother nature last season. I've been driving it every day since and have observed a .01% improvement in mileage :).
 
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