Measurement of aerodynamic forces and flow field of a soccer ball in a wind tunnel for knuckle effect

Murakami, Masahide; Kondoh, Masakazu; Iwai, Yuki; Seo, Kazuya

doi:10.1016/j.proeng.2010.04.017

Cited by 10 publications

(7 citation statements)

References 6 publications

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“…Asai and Seo 14 show the effect of drag by plotting the ball path in the vertical plane. Murakami et al 15 show the lateral deviation against time, and Hong et al 16 show the difference in point of impact. While all of these methods are applicable and useful to the study in question, not having standardised tests or performance measures makes it impossible to compare results between the tests.…”

Section: Characterisation Proceduresmentioning

confidence: 99%

Characterisation of football trajectories for assessing flight performance

Ward

Passmore

Spencer

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part P:

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Much discussion surrounds the flight of association footballs (soccer balls), particularly where the flight may be perceived as irregular. This is particularly prevalent in high-profile competitions due to increased camera coverage and public scrutiny. All footballs do not perform in an identical manner in flight. This article develops methods to characterise the important features of flight, enabling direct, quantitative comparisons between ball designs. The system used to generate the flight paths included collection of aerodynamic force coefficient data in a wind tunnel, which were input into a flight model across a wide range of realistic conditions. Parameters were derived from these trajectories to characterise the in-flight deviations across the range of flights from which the aerodynamic performance of different balls were statistically compared. The amount of lateral movement in flight was determined by calculating the final lateral deviation from the initial shot vector. To quantify the overall shape of the flight, increasing orders of polynomial functions were fitted to the flight path until a good fit was obtained with a high-order polynomial indicating a less consistent flight. The number of inflection points in each flight was also recorded to further define the flight path. The orientation dependency of a ball was assessed by comparing the true shot to a second flight path without considering orientation-dependent forces. The difference between these flights isolated the effect of orientation-dependent aerodynamic forces. The article provides the means of quantitatively describing a ball's aerodynamic behaviour in a defined and robust mathematical process. Conclusions were not drawn regarding which balls are good and bad; these are subjective terms and can only be analysed through comprehensive player perception studies.

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Section: Characterisation Proceduresmentioning

confidence: 99%

Characterisation of football trajectories for assessing flight performance

Ward

Passmore

Spencer

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part P:

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“…] = 0o n Ŵ, ( 7 ) [[ (C : ∇u) • n]] = 0o n Ŵ, ( 8 ) where ":" denotes the scalar-tensor product and ∇ represent the covariant derivative operator.…”

Section: Statement Of the Heterogeneous Elastic Problemmentioning

confidence: 99%

“…Textile composites have an important application in sports, where the development of new materials via physical and mathematical design has changed the usual perspective and strategy. For example, the development of new, resistant, aerodynamic and elastic balls has improved the attractiveness of sports such as soccer [7] and baseball [8,9].…”

Section: Introductionmentioning

confidence: 99%

Assessment of models and methods for pressurized spherical composites

Guinovart-Sanjuán

Rizzoni

Rodrı́guez-Ramos

et al. 2016

Mathematics and Mechanics of Solids

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The elastic properties of a spherical heterogeneous structure with isotropic periodic components is analyzed and a\ud methodology is developed using the two-scale asymptotic homogenization method (AHM) and spherical assemblage\ud model (SAM). The effective coefficients are obtained via AHM for two different composites: (a) composite with perfect\ud contact between two layers distributed periodically along the radial axis; and (b) considering a thin elastic interphase\ud between the layers (intermediate layer) distributed periodically along the radial axis under perfect contact. As a result,\ud the derived overall properties via AHM for homogeneous spherical structure have transversely isotropic behavior.\ud Consequently, the homogenized problem is solved. Using SAM, the analytical exact solutions for appropriate boundary\ud value problems are provided for different number of layers for the cases (a) and (b) in the spherical composite. The\ud numerical results for the displacements, radial and circumferential stresses for both methods are compared considering\ud a spherical composite material loaded by an inside pressure with the two cases of contact conditions between the layers\ud (a) and (b)

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“…In a non-spinning ball, twin vortices are formed in the wake of the ball, and jets between the vortices cause the lateral force. The presence of twin vortices and jets in the wake of the ball has been confirmed by visualization measurements using smoke [4] and tuft grids [5]. Synchronized measurements of the lateral force and the wake vortex using 3D-PIV (three-dimensional Particle Image Velocimetry) showed that, the jet was the cause of the lateral force.…”

Section: Introductionmentioning

confidence: 76%

Effect of Soccer Ball Panels on Aerodynamic Characteristics and Flow in Drag Crisis

2020

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The panel patterns of soccer balls that change with each World Cup have a significant impact on the balls’ aerodynamic and flight characteristics. In this study, the aerodynamic forces of eleven types of soccer ball with different panel patterns were measured in a wind tunnel experiment. We characterized the panel shapes of soccer balls by the length, cross-sectional area, and the panel grooves’ volume. The results confirmed that the drag and drag crisis characteristics are dependent on the groove length and volumes. Flow separation points were visualized by an oil film experiment and particle image velocimetry (PIV) measurement to understand the drag crisis of the soccer balls. The results showed that the panel shape of the ball significantly changes the position of the separation point near the critical region, where the drags crisis occurs. In the critical region, laminar and turbulent flows coexist on the ball. On the other hand, the effect of panel shape on the separation point position is small in subcritical and supercritical states.

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Measurement of aerodynamic forces and flow field of a soccer ball in a wind tunnel for knuckle effect

Cited by 10 publications

References 6 publications

Characterisation of football trajectories for assessing flight performance

Characterisation of football trajectories for assessing flight performance

Assessment of models and methods for pressurized spherical composites

Effect of Soccer Ball Panels on Aerodynamic Characteristics and Flow in Drag Crisis

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