Effect of Surface Groove Structure on the Aerodynamics of Soccer Balls

Soccer balls have undergone dramatic changes in their surface structure that can affect their aerodynamics. The properties of the soccer ball surface such as the panel shape, panel orientation, seam characteristics, and surface roughness have a significant impact on its aerodynamics and flight trajectory. In this study, we performed wind-tunnel tests to investigate how the introduction of grooves on the surface of a soccer ball affects the flight stability and aerodynamic forces on the ball. Our results show that for soccer balls without grooves, changing the panel orientation of the ball causes a significant change in the drag coefficient. Soccer balls with grooves exhibited a smaller change in air resistance (Cd) in the supercritical region (20 to 30 m/s; 3.0 × 105 ≤ Re ≤ 4.7 × 105), compared to the ungrooved ball where only the panel orientation was changed. Furthermore, at power-shot speeds (25 m/s), the grooved ball exhibited smaller variations in lift force and side force than the ungrooved ball. These results suggest that a long groove structure on the surface of the soccer ball has a significant impact on the air flow around the ball in the supercritical region, and has the effect of keeping the air flow separation line constant.

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Effect of surface “groove” structure of carbon nanotube bundles on the formation of nanohybrid shish kebab

Journal of Materials Research ◽

10.1557/jmr.2012.315 ◽

2012 ◽

Vol 27 (21) ◽

pp. 2812-2818 ◽

Cited By ~ 6

Author(s):

Nanying Ning ◽

Wei Zhang ◽

Jiajie Yan ◽

Fan Xu ◽

Changyu Tang ◽

...

Keyword(s):

Carbon Nanotube ◽

Nanotube Bundles ◽

Groove Structure ◽

Surface Groove ◽

Image Position ◽

Effect Of Surface

Abstract

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The Flight Trajectory of a Non-Spinning Soccer Ball

The Impact of Technology on Sport II ◽

10.1201/9781439828427.ch55 ◽

2007 ◽

Author(s):

T Asai ◽

O Kobayashi ◽

M Carr√© ◽

K Seo ◽

S Barber

Keyword(s):

Flight Trajectory ◽

Soccer Ball

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Analysis of Air Permeability of Insulated Masonry Walls

Energies ◽

10.3390/en13102654 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2654

Author(s):

Valdemaras Geležiūnas ◽

Karolis Banionis ◽

Raimondas Bliūdžius ◽

Valdas Paukštys ◽

Jurga Kumžienė

Keyword(s):

Air Flow ◽

Air Permeability ◽

Masonry Wall ◽

Mineral Wool ◽

Masonry Walls ◽

Standard Methods ◽

Air Resistance ◽

Protection Layer ◽

The Individual ◽

Flow Resistances

Recently, the construction of external ventilated walls has become popular for public and office buildings. These blocks are used without internal rendering because of their good interior surface, stable dimensions and various filling of masonry joints, which provide an attractive architectural appearance. However, problems with the airtightness of such walls often occur. Currently, there are no standard methods to predict the airtightness of such wall. In practice, samples of particular walls are produced, and their air permeability is measured at laboratories. For the broader use of the results of laboratory air permeability measurements, a methodology has been developed to predict the air permeability of block masonry walls using experimentally determined air flow resistances of the individual layers. The masonry from various blocks were used for the research; mineral wool boards of various air permeability were used for thermal insulation and the wind protection layer. After measuring the air resistance of the samples, the air flow resistances of walls of different construction were calculated. This study compared the calculated and measured air permeability values of different wall masonry samples and evaluated the suitability of created calculation method for prediction of the airtightness of insulated block masonry wall.

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Optimization of Lift Generation for a Spinning Surface through its Design and Speed

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.793.630 ◽

2015 ◽

Vol 793 ◽

pp. 630-634

Author(s):

Azharrudin Asrokin ◽

Mohammad Rizal Ramly

Keyword(s):

Rotational Motion ◽

Cylindrical Surface ◽

Lift Force ◽

Rotating Cylinder ◽

Golf Ball ◽

Tennis Ball ◽

Straight Path ◽

Soccer Ball ◽

The One

The rotational motion of a ball, be it a tennis ball, a golf ball or even a soccer ball, will yield a curving trajectory during airborne. We would best describe this phenomenon by its popular handle, the curve ball. The vortex generated by the ball is the one responsible for such behavior. Basically, the stronger the vortex, the more enhanced the arched flight we will get. Simply put, the ball is producing lift, thus the inclination to deviate to one side from otherwise a straight path. The same principle was employed to harness lift force in rotating cylinder. The question is, how strong the vortex should be and how much is too much. In this paper, we found that certain shape and speed (to make the surface rougher and yield stronger vortex) of the cylindrical surface will determine whether or not it generates better lift when the surface is rotating.

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