May 16, 2006

Engineers, computer experts take swing at improving golf ball design

Golf's pioneers wasted little time putting the game's evolutionary process into motion by experimenting with equipment designs to enhance players' proficiency.

One of the earliest advances involved the texture of the ball. The first golf balls had relatively smooth surfaces. But players discovered that as balls became nicked, grooved, gouged, rutted or otherwise given a rough surface, the balls could be hit farther. That led eventually to the modern dimpled golf ball.

This, however, is only the starting point for a small team of ASU engineers and computer experts. They're at work on models for the ultimate golf ball design, employing today's high technology in the quest for a ball that achieves maximum flight efficiency.

Their tools are some of the most advanced mathematical modeling methods, high-performance computing systems and three-dimensional visualization techniques.

“We have a convergence of expertise and technology in each of these areas here at ASU,” explains Dan Stanzione, an assistant professor with the Ira A. Fulton School of Engineering who directs the university's High-Performance Computing Institute.

Stanzione is working on the golf ball research with project leader Kyle Squires, a Fulton School professor of mechanical and aerospace engineering. They're supported by a team at the university's Decision Theater, a state-of-the-art, three-dimensional visualization laboratory.

Squires has been researching techniques for computing aerodynamic flow around spheres and other objects for years, mostly involving aircraft design and performance modeling for the U.S. Department of Defense. But last year, the ASU researchers were asked by Srixon, an international sports equipment company, to apply their research capabilities to golf ball design.

Squires and Stanzione say the project sounded fascinating from an engineering standpoint. It also presented an opportunity to showcase what their research could offer to industries – and the public – beyond the arena of military defense applications. But it would require producing precise aerodynamic analyses.

“We were motivated by the challenge,” Squires says. “Could we do the same thing we did in aircraft modeling with a golf ball, and get results from computer modeling that would be close to physical reality?”

It's all about turbulence. The way a golf ball acts in flight is largely determined by friction created by air flowing around the ball. Manipulation of that flow – and the turbulence that results – is the key factor to achieving greater distance.

“Traditionally, models that have been applied to air flow around a golf ball have not been able to accurately account for the effects of turbulence,” Squires says. “The techniques we are using are substantially more accurate.”

It's well known that the number of dimples – their size, shape and configuration on the surface of a ball – controls the ball's flight dynamics. But finding out how variations in dimple sizes, shapes and patterns will affect the ball requires knowing “every tiny little detail of air flow around the ball,” Stanzione says. “That requires some enormously complicated computational fluid dynamics modeling. It's something that takes a highly sophisticated computing platform.”

Then there's the matter of translating the results of the simulation into a visual demonstration of the effects of turbulence on golf ball behavior.

That's where the Decision Theater comes in. Its three-dimensional projection capability provides an intricate view of airflow around a golf ball. Researchers can visually map and measure the patterns, velocity and intensity of turbulence, even tracking how air moves over, into and out of individual dimples on the ball.

So far, the modeling has been based on simulating a golf ball moving at 125 mph, but Squires and Stanzione also want to explore how various ball designs would act in a variety of slower “flow regimes.” That means simulating a ball's performance not only for a drive, but for other types of golf shots.

In addition, the research team hopes to eventually use its modeling and visualization technology to investigate how particular ball designs would perform in different environmental conditions – in strong winds, in high humidity or at high altitudes.