Flutter ball

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A curling free kick is one with an irregular trajectory Locomotive ball in ball sports .

causes

There are different ways of creating flutter balls:

Slowly or non-rotating ball

With balls that only rotate slowly , there is no stabilizing effect corresponding to the conservation of angular momentum . The flow behind bodies is unstable. There are alternating vortices . The shedding of the vertebrae is also influenced by unevenness in the surface of the ball. This creates asymmetrical lift forces that can lead to sudden changes in the flight path. Even with balls that do not rotate at all, this effect can occur under certain conditions. An example of a slowly rotating flutter ball is the knuckle ball in baseball .

Rotating ball

In the case of "cut" balls that rotate in flight, an inverse Magnus effect occurs above a critical flight speed , which causes the ball to be deflected in one direction. If the speed falls below the critical speed due to the braking effect of the air resistance in the further flight, the normal Magnus effect sets in, whereby the ball is deflected in the opposite direction. The limit speed depends on the size, weight and design of the ball.

Soccer

Shots on goal with irregular trajectories are more difficult for goalkeepers to hold.

In the run-up to the 2008 European Football Championship , some goalkeepers told the media that the effect was particularly strong with the Europass , the match ball for the 2008 European Championship . The discussion repeated itself with the introduction of the uniform ball called Torfabrik for the Bundesliga in the 2010/11 season.

volleyball

In volleyball there is the so-called flutter service or flutter service, in which the ball is played centrally, with an outstretched, rigid hand without flapping the wrist with short contact.

literature

Soccer
  • John Wesson: Football - science with a kick. From the physics of flying balls and the statistics of the outcome of the game . Spectrum, Heidelberg 2006, ISBN 3-8274-1665-5 .
  • Leopold Mathelitsch, Sigrid Thaller: Football with a scientific dimension: banana flanks, flutter balls, header fights . In: Physics in Our Time . tape 37 , no. 3 , 2006, p. 122–125 , doi : 10.1002 / piuz.200601101 .
  • Metin Tolan: This is how we become world champions. The physics of the soccer game . Piper, Munich 2010, ISBN 978-3-492-05355-6 .
volleyball
  • Max Meier, Peter Nussbaum: volleyball for children. a teaching aid for trainers and teachers . Brunner, Kriens 1994, ISBN 3-905198-09-6 .
  • Don Shondell, Cecile Reynaud (Ed.): The Volleyball Coaching Bible . Human Kinetics, Champaign 2002, ISBN 0-7360-3967-8 .
baseball
  • Robert Kemp Adair: The Physics of Baseball . 2nd Edition. HarperPerennial, New York 1994, ISBN 0-06-095047-1 .

Web links

Wiktionary: Flatterball  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ^ Robert G. Watts, Eric Sawyer: Aerodynamics of a knuckleball . In: American Journal of Physics . tape 43 , no. 11 , 1975, p. 960-963 , doi : 10.1119 / 1.10020 .
  2. ↑ Metin Tolan: This is how we become world champions. The physics of the soccer game . Piper, Munich 2010, ISBN 978-3-492-05355-6 .
  3. ↑ Czech goalkeeper criticizes flutter ball. In: Der Tagesspiegel. June 6, 2008.
  4. ↑ The great flutter. In: sportschau.de. June 6, 2008.
  5. ↑ Flatterball 'Torfabrik' annoys Bundesliga players
  6. ↑ Tennis service for beginners.  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. In: Practice supplement. No. 1, 2009 (PDF; 642 kB).@1@ 2Template: Dead Link / www.volleyball.ch  
  7. ↑ Don Shondell, Cecile Reynaud (Ed.): The Volleyball Coaching Bible . Human Kinetics, Champaign 2002, ISBN 0-7360-3967-8 , Serving.
  8. ↑ Max Meier, Peter Nussbaum: Volleyball for children. A teaching aid for trainers and teachers . Brunner, Kriens 1994, ISBN 3-905198-09-6 , surcharge from below and above.