| Project/Area Number |
15500424
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Sports science
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| Research Institution | Yamagata University |
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Principal Investigator |
ASAI Takeshi Yamagata University, Faculty of Education, Associate Professor, 教育学部, 助教授 (00167868)
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| Co-Investigator(Kenkyū-buntansha) |
SEO Kazuya Yamagata University, Faculty of Education, Associate Professor, 教育学部, 助教授 (60292405)
SASASE Masashi Yamagata University, Faculty of Education, Associate Professor, 教育学部, 助教授 (50250907)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2004: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2003: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | cuve kick / soccer / FEM / fluid / wind tunnel / drag / カーブ / インパクト / ボール |
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| Research Abstract |
The purpose of this study was to analyze the fundamental characteristics that cause a football to spin in an infront curve kick. Experimental studies of football players showed that the average foot velocity was 24.2 m/s and the average ball velocity was 27.1 m/s. The average spin rate was 7.8 revolutions per second. The attacking angle between the face vector and the swing vector at impact was also observed in each trial and the average attacking angle was found to be 35.4 degrees. Finite element models of the infront curve kick showed that the spin rate of the ball increases as attacking angle is increased. However, the spin rate falls rapidly in the case of the attacking angle being 75 degrees or greater. The ball velocity decreases as the attacking angle is increased. It is considered that, for the infront curve kick, a foot orientation at impact, with the attacking angle between the face vector and the swing vector, generates the optimum moment with which to generate ball spin.
In the wind tunnel test, it is found that the biggest aerodynamic difference between the soccer ball and the smooth sphere is the Reynolds number dependency of the drag coefficient. In the case of the smooth sphere, the drag coefficient is almost 0.43 for Re<3.1×10^5, and 0.11 for Re>3.5×10^5. The critical Reynolds number is about 3.1×10^5. These values are comparable with the conventional data. On the other hand, the drag coefficient of the soccer ball is independent of the Reynolds number. The drag coefficient is constant around 0.2.
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