Their grace and elegance in spreading their wings and fly-off, has
been a reason of deep thinking for the man who seeks answers. Since
the Ancient Greece time, the great philosophers of that era reflected
on the fact that how it was possible for some creatures to rise up in
the sky and cover amazing distances with such a great harmony. A
famous greek mythology legend states that Icarus was the first man to
fly.
The attempts for man to fly has been unsuccesful until December17th,
1903 when Wright Brothers managed to accomplishthe fateful task so
much desired by the men of all the times. This first flight lasted 61
meters at a speed of about 43 km/h using a rudimentary airplane built
by thesame two brothers. From that day, the technological advance has
allowed the improvement in an exceptional way of that first
rudimentary attempt to imitate the bird's flight. Today, we can see
airplanes of different sizes and shapes fly in the skies of theEarth
like birds. As probably everyone of us know, the airplanes' wing
perfectly imitate those of the birds. Like the bird'swings, those of
the airplanes do have the upper part curved and not just flat. In this
way, when engines generate a thrust, that particular shape makes
possible for the air that flows in the upper part of the wing travel
faster than that in the lower part.As a consequence, a vertical thrust
is generated which allows to overcome the gravity force and in this
way the plane can lift up and fly like a bird.
That description presented above is a semplified one, since a lot of
complex mathematics and physics is need to acurately describe the
dynamic of flight, but that allows to grasp the simple principle that
is behind the technology that everyone or almost of us have personally
experimented. But man didn't stop here. He wanted again to draw
inspiration from the masters of flight which are the birds. Big birds
like eagles, hawks, vultures etc. do have wings with a particular
structure with respect to the many other varieties of birds. At their
wing's extremities, they have some "winglets" of different sizes which
allows to eliminate the vertical vortex created around the wing and
this fact can reduce the drag experimented by the wing (fig. 2, 3).
Indeed, during the flight these winglets curve-up almost vertically
making the wing non-planar andso greatly reduce the drag. With such a
particular wing structure, these big birds can fly with the minimum
effort and without consuming a lot of energy. Only recently man has
realized this fact and could "copy" and implement this astonishing
detailfor his own purposes. Now, a great number of air companies equip
their airplanes with this apparently simple device (fig. 1,4). Just
like those of the birds, these man-made winglets make possible to
eliminate vortexes (fig. 1) that are created around the plane's wings
and with the consequence that:
-the airplane's fuel consumption is reduced so it also pollutes less
- using these winglets, the airplane needs smaller wings to generate
the same vertical lift compared with that which doesn't have them. In
this way, one can build smaller airplanes that consume less fuel and
need smaller airports
As we have seen till now, the birds are perfect flying machines,
designed in the most efficient and perfect possible way. From these
marvelous creatures, man has been able to draw his inspiration and
build his own flying machines and realize his biggest dream: to fly
like a bird. With the discoveries about these winglets, Allah has
showed us again His infinite power and wisdom.
"Do they not see the birds controlled in the atmosphere of the sky?
None holds them up except Allah . Indeed in that aresigns for a people
who believe." (Surat An-Nahl, 79)
"Haven't they looked at the birds above them, with wings outspread and
folded back? Nothing holds them up but the All-Merciful. He sees all
things." (Qur'an, 67: 19)
2011-10-09 17:18:01
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