Re: Why don't wings have dimples?


"Alan Baker" <alangbaker@xxxxxxxxx> wrote in message
news:alangbaker-4B0CFE.00084712062006@xxxxxxxxxxxxxxxxx
In article <1150069926.345327.79420@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"Dancing Fingers" <bcl122@xxxxxxxxxxxx> wrote:

Hi all,
I always wanted to build my own airplane but the time and money has
eluded me. So I've decided to design and build my own recumbent trike,
with farings. This brings me to my question, if golf balls have
dimples, to help them sail further, why don't wings -- especially for
STOL aircraft? Would putting dimples in my faring reduce my wind
resistance?
Just curious.
Chris

First of all, golf balls have dimples because in order to create lift
they need to influence the air passing by them with the golf ball's
spin. The dimples help to make the air slow down beneath the ball and
speed up above it; creating downward flow.

I believe that you have the effect exactly backward. The spin, which should
only be significant using the more steeply pitched irons; slows the relative
speed over the "top" of the ball and causes it to remain attached longer,
while the air flowing under the bottom breaks away more quickly, which would
result in a slight net lift. It also explains why a "slice" curves as it
does--which is why a smooth ball would have improved my game. :-(

Wings produce that downward flow with their shape.

Exactly.

Peter


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Relevant Pages

  • Re: Buddy golf balls
    ... Presumably golf balls have dimples rather than grooves because golf balls turn in the air and they don't know which way the air is going to come from, so round dimples will take the air from any direction. ... The longer answer is the issue of dimples is to do with boundary layer separation, and along the side of a railway vehicle there should be no separation with or without surface features of this kind. ...
    (uk.railway)
  • Buddy golf balls
    ... Presumably golf balls have dimples rather than grooves because golf ... balls turn in the air and they don't know which way the air is going ... In the case of a railway vehicle you know which way the air is coming ...
    (uk.railway)
  • Re: Why dont wings have dimples?
    ... Would putting dimples in my faring reduce my wind ... golf balls have dimples because in order to create lift ... they need to influence the air passing by them with the golf ball's ... Wings produce that downward flow with their shape. ...
    (rec.aviation.homebuilt)
  • Re: Hurricane Forecasting is inaccurate
    ... >> than the same ball that is constructed without dimples. ... > When an object moves through air the friction between the ... > the moving object sheds spinnig vortices of air behind it. ... > The energy goes into spinning the vortices. ...
    (rec.bicycles.racing)
  • Re: Why dont wings have dimples?
    ... Peter Dohm wrote: ... Air is sticky. ... and changes throughout the Lift phase of the flight). ... The "Happy Non_Hooker" ball only had dimples in a band around the ball. ...
    (rec.aviation.homebuilt)