Samba glory&quot

if you know enough community will know, honeycomb football since 2006 have changed. The World Cup soccer "the star of the group," football epidermis from 32 down to 14 block, the splicing point of the outer surface of the ball from the 60 change in the original 24, the total length of the seam line from 40.05 cm to 33.93 cm, to maximize the elimination of concave and convex spherical surface irregular sphere, that presents a perfect arc, so as to improve football running accuracy.

however, this change to the 2010 World Cup in South Africa is controversial, the world cup in South Africa using "celebrate" appears also claimed to be the most stable, the most perfect football, with only 8 pieces of leather stitching, but its performance has been criticized as players, its performance is not stable, it is difficult to predict the flight path Cheap Manchester City Jerseys "", a well-known British goalkeeper also therefore had "hands" of the title, because the ball is old from his hand away "". "Celebrate" the goal rate is the lowest in the world cup.

Is it right? Because the ball design lead to this phenomenon?

This year

, from the University of Tsukuba, two sports scientific research personnel of the wind tunnel test, on several different other football tests show, leather block direction has an effect on the air resistance, air resistance of 6 pieces of leather football lowest, followed by 32 pieces of skin. The researchers found that, when the robot soccer, football skin block direction has a significant effect on football flight path, namely skin block direction will be significantly interfere with the flight of the ball. 6 pieces of leather and 32 traditional leather football, showed a relatively stable and regular flight routes. They analyzed the "Samba glory", "the star of the group" II, "celebrate" and the traditional 32 soccer, results, "Samba glory" is the most Lyon Jerseys Cheap stable Cheap Arsenal Jerseys in these spheres, followed by the 32 side football tradition, and the controversial "Jabulani" It is as expected, the worst performance in the test.

why is there such a result? The reporter interviewed experts Gu Yunsong professor of Nanjing University of Aeronautics & Astronautics nanjing. Gu Yunsong tells a reporter, the ball body in aerodynamics of bluff body, not a streamlined body, so they fly in the air force is very complicated, so there will be a variety of unstable state. But under the same conditions (such as playing strength, the weight of the ball and so on), surface roughness of the ball to fly farther than a smooth ball. This is why?

and Gu Yunsong said, we usually think of rough ball will have greater resistance, but that only considering the friction resistance, the ball is subjected to a pressure drag in flight, which is acting on the ball before and after the resistance, Cheap Chelsea Jerseys the resistance is greater than the impact of friction. The ball in flight, will produce a "boundary layer effect", if the surface is rough, can produce all kinds of turbulence in the ball boundary, the Cheap Liverpool Jerseys turbulence affects the ball's flight speed and line. In the sphere of flight, the surface is rough ball, the pressure resistance smaller, so rough ball will fly farther.

This effect of

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