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Aerodynamics When a
golf ball is hit, the impact, which lasts less
than a millisecond, determines the balls
velocity, launch angle and spin rate, all of which
influence its trajectory (and its behavior when it
hits the ground).
A
ball moving through air experiences two major
aerodynamic forces, lift and drag. Dimpled balls
fly farther than non-dimpled balls due to the
combination of two effects:
Firstly, the dimples delay separation of
the boundary layer from the ball. Early
separation, as seen on a smooth sphere, causes
significant wake turbulence, the principal cause
of drag. The separation delay caused by the
dimples therefore reduces this wake turbulence,
and hence the drag.
Secondly, backspin generates lift by
deforming the airflow around the ball, in a
similar manner to an airplane wing. This is called
the Magnus effect. Backspin is imparted in almost
every shot due to the golf club's loft (i.e. angle
between the clubface and a vertical plane). A
backspinning ball experiences an upward lift force
which makes it fly higher and longer than a ball
without spin.[1] Sidespin occurs when the clubface
is not aligned perpendicularly to the direction of
swing, leading to a lift force that makes the ball
curve to one side or the other. Unfortunately the
dimples magnify this effect as well as the more
desirable upward lift derived from pure backspin.
(Some dimple designs are claimed to reduce
sidespin effects.)
In order to keep the aerodynamics optimal, the
ball needs to be clean. Golfers can wash their
balls manually, but there are also mechanical ball
washers available.
Used
and refurbished golf balls
Used golf balls are golf balls that have
been played, most likely hit into a water hazard,
then retrieved, cleaned up and resold. Used golf
balls comes in different gradings - one
well-accepted standard is:
| AAAAA (1st Quality) |
AAAA
(2nd Quality) |
AAA
(3rd Quality) |
AA
(4th Quality) |
| Highest quality ball in the marketplace.
Like new, perfect to very near perfect. A "One
Hit Wonder" Ball.
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Very slightly blemished balls. May have
minor imperfections.
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Slightly scuffed or blemished balls that
may have minor discoloration.
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Appropriate for range and green practice.
Survived a round of
golf.
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Refinished, sometimes called reconditioned
or refurbished, golf balls are different than
used. Refinished golf balls may look new, but do
not meet the manufacturer's original requirements.
In the processing procedure, the golf ball is
stripped of its original surface paint and
reprinted with the original markings, then a new
clear/coat is applied.
Design These two balls are
disclosed in U.S. Patent 4,560,168 . These two
balls are easily made with a two-piece mold. Since
there is no dimple located on any of the
slash-dotted circles (one is marked red), the mold
can be two hemispheres.Dimples first became a
feature of golf balls when a certain Taylor
patented a dimple design in 1908. Other types of
patterned covers were in use at about the same
time, including one called a "mesh" and another
named the "bramble", but the dimple became the
dominant design due to "the superiority of the
dimpled cover in flight".[4]
Most golf balls on sale
today have about 250 450 dimples. There were a
few balls having over 500 dimples before. The
record holder was a ball with 1,070 dimples 414
larger ones (in four different sizes) and 656
pinhead-sized ones. All brands of balls, except
one, have even-numbered dimples. The only
odd-numbered ball on the market is a ball with 333
dimples, called the Srixon AD333.
Officially sanctioned
balls are designed to be as symmetrical as
possible. This symmetry is the result of a dispute
that stemmed from the Polara, a ball sold in the
late 1970s that had six rows of normal dimples on
its equator but very shallow dimples elsewhere.
This asymmetrical design helped the ball
self-adjust its spin-axis during the flight. The
USGA refused to sanction it for tournament play
and, in 1981, changed the rules to ban aerodynamic
asymmetrical balls. Polara's producer sued the
USGA and the association paid US$1.375 million in
a 1985 out-of-court settlement.
Golf equipment maker
Callaway has introduced a ball with hexagonal
dimples to increase the dimpled area on a golf
ball, as hexagons tesselate unlike
circles.
The United States
Patent and Trademark Office's patent database is a
good source of past dimple designs. Most designs
are based on Platonic solids such as
icosahedron.
Golf balls are usually
white, but are available in other high visibility
colours , which helps with finding the ball when
lost or when playing in frosty conditions. As well
as bearing the makers name or logo, balls are
usually printed with numbers or other symbols to
help players identify their
ball.
Some
interesting facts about Golf
Balls
Have you ever wondered
what Tiger Woods found in Golf that he decided on
pursuing it as his career? Like any other sports
lover, you would answer, passion. Blending
elegance with strength, you hit white golf balls
with clubs and the balls fly and land in the hole,
its destination. There are many factors that
determine how the ball will swing or will swing at
all, or not. Physical elements like aerodynamics,
pressure of air and structure of the surface are
some of them. But another crucial factor that we
often seem to ignore is the quality of golf
balls.
Selection of wrong golf
balls lead to missing a good swing that eventually
leads you to miss a game too. Even if you are
equipped with proper shoes, tees and clubs, they
cannot help you recover from the damage that is
made by the selection of improper golf balls. A
golf ball must be in accordance with the
circumstances; otherwise even the best shot will
be a futile one.
Basically there are
three types of golf balls. They are balata, a
two-piece set and a blend of both these kinds.
However, which one is going to suit you best
depends on certain factors. First of all, you
should be focused about your requirement. If you
want your golf balls to have control as well as
spin, you should go for balata. It is soft with
even softer cover which gives extra spin to the
balls. The stalwarts of the field use this
expensive variation of golf balls.
If you want the ball to
fly high and cover more distance, it is better if
you opt for the two-piece set of golf balls. They
are durable balls with tough outer layer to
prevent backspin and when hit, goes farther. Often
circumstances determine which kind of balls to
play with. These may include terrain, weather and
temperature. For example, on a rocky mountainous
terrain with hard track, the balata is a better
option as it would land softly and spin more.
Similarly, on a wet deluged track hard covered
golf balls serve a better purpose.
The structure of golf
balls has a special purpose. The dimples on the
surface cut down the drag of aerodynamics. Smooth
surface hampers the flight of balls because the
air-pocket created by them while sailing through
is quite a huge one. This creates drag which
retards the velocity of the ball. On the other
hand, dimples reduce the pressure differential,
which reduces the drag as well. The turbulence
created by the ball grasps it more tightly. This
way, air follows the distortion made by the ball.
This reduces the drag enhancing the velocity and
distance. According to Royal and Ancient Golf Club
(R&A) regulations, standard number of dimples
in a golf ball is 250 to 450.
Color of the golf balls
is generally white. But again, depending on
certain factors like climatic conditions and
location they differ. As for example while playing
in frosty climate or in poor visibility, bright
colored balls are used so that they can be located
easily.
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