Computational fluid dynamics (CFD) is one of the fastest growing components of the Computer Aided Engineering (CAE) market. CFD software turns a computer into a virtual laboratory. Engineers can study how fluid flow, heat and mass transfer, and other related phenomena involving turbulent, reacting, and multiphase flow affect their designs.
Recently, CFD was used to gain greater insight into the effects of soccer player kicks on soccer balls. This pioneering work was conducted at the University of Sheffield, UK in collaboration with Fluent Europe Ltd., a developer of CFD software.Some of the world’s greatest goalkeepers have been beaten by unusual swerving balls that move to the left and the right before hitting the back of the net, even though they have little or no spin applied to them. To understand this phenomenon, the university researchers used CFD software to simulate the physics of airflows in and around soccer balls. They studied four balls, all with different panel designs that were used at different periods over the past 36 years, up to, and including the new Adidas ball used in the 2006 World Cup.
It turns out that the shape and surface of the ball, as well as its initial orientation, affect the ball’s trajectory through the air.
A 3D laser scanner measured surface detail of each ball, which was entered into the CFD program. The researcher’s studies showed that side forces on a ball vary according to the orientation of the ball relative to its flight. If a player kicks a ball to rotate slowly, the side force could fluctuate causing the ball to swerve. The study further showed that the shape as well as the initial orientation of the ball determines the nature of the swerve.
The researchers work indicates that any non-uniformity of design or asymmetry of manufacture will affect the side forces of the ball. Researchers concluded that computer-based simulation might allow engineers to predict ball aerodynamics, opening new directions in soccer ball design and manufacture, as well as in player strategy.
CFD indicates the high speed airflow path lines for an Adidas Teamgeist 2006 soccer ball.
The lines are colored according to local velocity.
Here, CFD simulations track the 32 panel Fevernova Ball geometry as it’s rotated through a 90° cycle around the X axis.
This image shows CFD predictions of surface shear stress patterns on the rear of the Fevernova Ball (left) and Teamgeist Ball (right) for a 0° tracking orientation (red indicates high shear, blue shows low shear)
Airflow pathlines colored by local velocity inside the FIFA World Cup Stadium in Munich with doors open. Red represents 1.5m/s.
Photos courtesy of Sports Engineering Research Group, University of Sheffield,
Sheffield, UK. Postprocessed using Ensight from CEI.
::Design World::
Source: :: Design World ::
