Search Results:　 1-20 of 21

  • 1

    Flow structure of knuckling effect in footballs

    Asai Takeshi , Kamemoto Kyoji , 淺井 武

    … The flight trajectory of a non-spinning or slow-spinning soccer ball might fluctuate in unpredictable ways, as for example, in the many free kicks of C. …

    Journal of fluids and structures 27(5-6), 727-733, 2011-00-00

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  • 2

    A38 Aerodynamic Characteristics of Knuckling Effect Ball in Soccer  [in Japanese]

    HONG Sungchan , SAKAMOTO Keiko , SEO Kazuya , ITO Shinichiro , ASAI Takeshi

    … The purpose of this study was to discuss the fluid mechanics acting on a non-spinning and low-spinning flight soccer ball, which called "Knuckling effect ball" or "Knuckleball", using the kick-robot. … It is planned to conduct experiments on the knuckle effect of a non-or low-spinning soccer ball. …

    ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics 2010, 167-172, 2010-11-02

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  • 3

    A-27 The aerodynamic characteristics of a rugby ball without the lace  [in Japanese]

    SEO Kazuya , SATO Takaaki

    … This paper describes the aerodynamic characteristics on the non-spinning rugby ball. …

    ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics 2009, 142-146, 2009-12-02

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  • 4

    A-17 A fundamental study on Knuckling Effect of non-spinning soccer ball  [in Japanese]

    HONG Sungchan , SUDA Syogo , NAKAYAMA Masao , ASAI Takeshi

    … The purpose of this study was to discuss the fluid mechanics and frequency of forces acting on a non-spinning and low-spinning flight soccer ball, which called "Knuckleball", using high-speed VTR image of a real place kick. …

    ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics 2009, 88-93, 2009-12-02

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  • 5

    A-16 Nonstationarity on knuckling effect ball in Soccer  [in Japanese]

    ASAI Takeshi , NAKAYAMA Masao , HONG Sungchan , NAITO Kiyoshi , SAKAMOTO Keiko , SUDA Syogo

    … The flight trajectory of a non-spinning or slow-spinning soccer ball may fluctuate in unpredictable ways as similar as C. …

    ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics 2009, 82-87, 2009-12-02

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  • 6

    S0506-1-1 PSP measurement on an ellipsoid with seams : The effect of seam on the pressure distribution  [in Japanese]

    SEO Kazuya , YORITA Daisuke , NAGAI Hiroki , Shiroishi Nana , ASAI Keisuke

    … Measurement of the aerodynamic force on a non-spinning rugby ball reveals that the side force depends on the position of the seam as well as the angle of attack. … Therefore, a slower spinning ball fluctuates during flight. …

    年次大会講演論文集 : JSME annual meeting 2009(2), 273-274, 2009-09-12

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  • 7

    The use of Self-Organizing Maps for visualizing aerodynamic characteristics of a non-spinning rugby ball  [in Japanese]

    Seo Kazuya , Sato Takaaki

    … This paper describes the trade-offs that can be made between three experimental parameters and four aerodynamic coefficients on the non-spinning rugby ball. …

    Proceedings, ... meeting of Japan Society of Fluid Mechanics 2009, 263, 2009-09-02

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  • 8

    A10 A wind tunnel experiment on aerodynamic force and flow-field around a non-spinning soccer ball  [in Japanese]

    IWAI Yutaka , MURAKAMI Masahide , SEO Kazuya

    This paper describes the behavior of wake-flow field behind a soccer ball measured in a wind tunnel with no or low spin based on the aerodynamic force data acting on the soccer ball. The experiment wa …

    ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics 2008, 57-62, 2008-11-05

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  • 9

    A7 Three-Dimensional Flight Analysis of Knuckle Effect of Soccer Ball with High-Speed Camera  [in Japanese]

    KONDO Masakazu , SAKURAI Yosuke , MURAKAMI Masahide , ASAI Takeshi , IWAI Yutaka

    … In this research, we focus on a knuckle effect on a low-spinning or non-spinning soccer-ball with the aid of three-dimensional image analysis for high-speed video images. … It is made clear that there are some hydrodynamic differences between the knuckle effect ball and the spinning ball. …

    ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics 2008, 43-48, 2008-11-05

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  • 10

    Fundamental Aerodynamics of Soccer Ball in High Reynolds Number Region(<Special Issue> "Progess of Fluid Science on Sports Engineering")  [in Japanese]

    ASAI Takeshi , SEO Kazuya , KOBAYASHI Osamu , ITO Shinichiro

    … The boundary layer and vortex-trail dynamics of a non-spinning soccer ball in flight were visualized using smoke of titanium tetrachloride, and were compared between the subcritical and supercritical regions. …

    Transactions of the Japan Society of Mechanical Engineers. B 73(734), 1993-1998, 2007-10-25

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  • 11

    1542 An Experimental Study on Unsteady Aerodynamic Forces Acting on a Non-Spinning Soccer Ball  [in Japanese]

    SEO Kazuya , BARBER Sarah , ASAI Takeshi , CARRE Matt , KOBAYASHI Osamu

    … In order to investigate the knuckle effect in soccer, we carried out wind tunnel tests of a non-spinning soccer ball. … This paper describes the aerodynamic characteristics of a non-spinning soccer ball. …

    年次大会講演論文集 : JSME annual meeting 2007(2), 177-178, 2007-09-07

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  • 12

    A fundamental study on flight behavior of non-spinning soccer ball  [in Japanese]

    Asai Takeshi , Seo Kazuya , Ito Shinichiro

    … The purpose of this study is to discuss the magnitude and the frequency of the side force of non-spinning and low-spinning flight soccer ball, which called "knuckle effect ball", using a high speed VTR image of a real place kick. …

    Proceedings, ... meeting of Japan Society of Fluid Mechanics 2007, 230, 2007-08-06

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  • 13

    A study of soccer ball aerodynamics  [in Japanese]

    Asai Takeshi , Seo Kazuya , Kobayashi Osamu

    本研究では,風洞実験により,無回転,及び回転するサッカーボールの空力係数を分析すると共に,四塩化チタンを用いた可視化手法により,実際に飛翔するボール後流の動態を検討し,サッカーボールの空力特性を明らかにしようとした.結果を以下に要約する.1)風洞実験における無回転ボールのレイノルズ数と抗力係数の関係をみると,亜臨界レンジで0.43程度,超臨界レンジで0.15程度を示し,サッカーボールの臨界レイノル …

    Research of physical education 52(1), 29-38, 2007-01-10

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  • 14

    A13 CFD analysis of soccer ball using LES model  [in Japanese]

    ASAI Takeshi , SEO Kazuya , KOBAYASHI Osamu , KOIKE Sekiya

    … The drag coefficient of non-spinning soccer ball in CFD was approximately 0.19 and that of wind tunnel test was about 0.15. … The separation point of the non-spinning soccer ball in CFD retreated to〜120°from the front-stagnation point and the vortex region shrank when the supercritical ball velocity was 25m/s. …

    ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics 2006, 68-72, 2006-11-08

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  • 15

    2403 Vortex visualization on real flight soccer ball in high Reynolds number  [in Japanese]

    ASAI Takeshi , SEO Kazuya , ITO Shinichirou

    … At an outside air speed of≤1.0m/s, the subject performed an almost non-spinning straight kick and a laterally spinning curved kick towards the middle of a goal from a distance of 15m. …

    年次大会講演論文集 : JSME annual meeting 2006(2), 125-126, 2006-09-15

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  • 16

    Simulation of a punt kicked rugby ball trajectory  [in Japanese]

    SEO Kazuya , KOBAYASHI Osamu , SAKAMOTO Shingo , MURAKAMI Masahide

    … This paper describes the simulation result of the flight trajectory of a punt kicked rugby ball on the basis of aerodynamic forces acting on a non-spinning ball. …

    ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics 2004, 282-287, 2004-11-09

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  • 17

    Behavior of a rugby ball during flight  [in Japanese]

    SEO Kazuya , KOBAYASHI Osamu , SAKAMOTO Shingo , MURAKAMI Masahide

    … Wind tunnel tests with a full size model were carried out to measure the aerodynamic forces on a spinning rugby football as well as those on a non-spinning ball. … It was found that the side force coefficient depends on the seam position except for an angle of attack of 0° in the case of a non-spinning ball. …

    年次大会講演論文集 : JSME annual meeting 2004(7), 45-46, 2004-09-04

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  • 18

    Aerodynamic Forces on a Spinning and Non-spinning Soccer Ball  [in Japanese]

    SEO Kazuya , ASAI Takeshi , KOBAYASHI Osamu , UBUKATA Hiroo

    … Wind tunnel tests with a full size model were carried out to measure the aerodynamic forces (drag, lift and side force) on a spinning soccer ball as well as those on a non-spinning ball. …

    ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics 2003, 9-13, 2003-11-07

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  • 19

    Aerodynamic forces on a spinning and non-spinning rugby football  [in Japanese]

    SEO Kazuya , KOBAYASHI Osamu , MURAKAMI Masahide

    … We carried out wind tunnel tests with a full size model to measure the aerodynamic forces on a spinning rugby football as well as those on a non-spinning ball. … In the case of a non-spinning ball, it also increases with increasing angle of attack up until a certain angle of attack. …

    Proceedings, ... meeting of Japan Society of Fluid Mechanics 2003, 80-81, 2003-07-28

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  • 20

    Recent Topics in Inertial Navigation System : Non-spinning Gyroscopes(<Special Issue>Aerospace Navigation)  [in Japanese]

    HIGASHIGUCHI Minoru

    Navigation (89), 76-81, 1986-09-25

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