{"id":395,"date":"2018-07-14T09:38:59","date_gmt":"2018-07-14T12:38:59","guid":{"rendered":"http:\/\/accuracyfea.com\/?p=395"},"modified":"2021-11-02T02:18:12","modified_gmt":"2021-11-02T05:18:12","slug":"importa-con-que-pelota-se-practican-los-equipos-de-la-copa-mundial-de-la-fifa","status":"publish","type":"post","link":"https:\/\/accuracyfea.com\/en\/2018\/07\/14\/importa-con-que-pelota-se-practican-los-equipos-de-la-copa-mundial-de-la-fifa\/","title":{"rendered":"Does It Matter Which Ball the FIFA World Cup\u2122 Teams Practiced With?"},"content":{"rendered":"

Does It Matter Which Ball the FIFA World Cup\u2122 Teams Practiced With?<\/span><\/h2>\n

This is the second installment of the analysis carried out by the COMSOL team on the official balls (Adidas\u00ae Telstar\u00ae and Nike\u00ae Ordem V) of the 2018 FIFA World Cup<\/b><\/span><\/p>\n

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Author:<\/strong> Ed Fontes<\/em><\/p>\n

June 6, 2018<\/em><\/p>\n

URL: <\/strong>Does It Matter Which Ball the FIFA World Cup\u2122 Teams Practiced With?<\/a><\/em><\/p>\n

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The Adidas\u00ae Telstar\u00ae soccer ball is the official ball of the 2018 FIFA World Cup\u2122, and the Nike\u00ae Ordem V soccer ball is used in the seven largest national leagues in Europe, including the top three: the Spanish La Liga, the English Premier League, and the Italian Serie A. Previously, <\/span><\/span>we discussed an experimental setup for measuring the terminal velocity of these two soccer balls<\/span><\/span><\/a> to see if there\u2019s a difference that could affect player performance. <\/span>Here\u2019s what we found\u2026<\/span><\/span><\/p>\n

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Setting Up the Soccer Ball Experiment<\/span><\/span><\/h3>\n

We have already concluded that the position of a soccer ball suspended above the tube of a leaf blower should be inversely proportional to the terminal velocity. <\/span>Therefore, a higher ball position corresponds to a lower terminal velocity, and a lower terminal velocity means a higher drag coefficient ( <\/span><\/span>C <\/span><\/span>d<\/span><\/span><\/sub><\/em> ). <\/span>We estimated that a difference between a <\/span><\/span>C <\/span><\/span>d<\/span><\/span><\/sub><\/em> value of 0.2 and 0.15 should give at least a 15% difference in the position of the ball above the leaf blower tube. <\/span>We concluded that we would be able to measure such a difference!<\/span><\/span><\/p>\n

So, on we went. Our Video team in Boston built the test rig under very strict instructions from me. I even made them wear white lab coats, shave, and cut their hair \u2014 all for the sake of getting into the right mode for the measurements. The \u201chigh-tech\u201d rig is shown in the figure below.<\/span><\/p>\n

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\nThe high-tech rig set up by the Video team in Boston during the proof of concept. Unfortunately, none of them wore lab coats, nor did they shave! Maybe they were also standing a little bit too close to the wall. The pipe was corrected later, since it was a bit crooked.<\/span><\/em><\/p>\n

Measuring the Distance from the Ball to the Tube<\/span><\/h3>\n

Alright, maybe it was not a high-tech test rig and maybe our team did not shave after all, but the measurements turned out pretty well. The videos below show the Adidas\u00ae Telstar\u00ae ball and the Nike\u00ae Ordem V ball suspended by the airflow from the leaf blower. We can also see the calibrated ruler that measures the position of the ball.<\/span><\/p>\n

We were able to sample about 110\u2013150 points in each time series once the ball was hovering at a relatively stable point above the leaf blower tube. For trademark reasons, we removed the logos from the balls afterward. But both balls are the real, high-end balls from the two manufacturers. The Nike\u00ae Ordem V ball is the winter ball, but besides the color, it should be a regular Nike\u00ae Ordem V ball with the Nike\u00ae Aerowtrac ball grooves and microtextured casing.<\/span><\/p>\n