It seems fair to say golf club innovation has reached a stage where the concept of making things “better” requires more effort than ever before. And perhaps nowhere is that complexity more apparent than in the area of aerodynamics.
Manufacturers have been studying and innovating on how to make drivers move through the air more efficiently for the better part of a decade. The forgiveness you can get from a large driver can be compromised by how its bulk negatively affects the way the club moves through the air. Trying to understand how to balance these factors has led manufacturers to seek partnerships with various independent and non-golf outlets. Adams Golf worked with Texas A&M a half-dozen years ago on its Speedline drivers. TaylorMade has gleaned knowledge from the San Diego Low Speed Wind Tunnel to improve its AeroBurner and M1 drivers. And, of course, Ping has championed the aerodynamics technology behind its successful G30 and recently introduced G driver, understanding fueled by a partnership with the Arizona State University.
Now, Callaway is breaking new ground in identifying the effect of aerodynamic drag on driver performance by partnering with a company whose primary function is getting big things moving through the air extremely efficiently. Boeing, the largest airline manufacturer in the world, helped Callaway’s new XR16 drivers combine a large clubhead with aerodynamic efficiency. It was not a simple exercise.
“For me, it’s a complicated question, quite honestly, because it’s a complicated problem,” said Jeffrey Crouch, senior technical fellow for flight sciences at Boeing. Remember, Crouch’s day job is to keep airborne something that weighs nearly 500 tons.
The partnership with Callaway (or for that matter, any company outside the airline industry) on the design of a product is rare for Boeing, but was an interesting endeavor because it wasn’t a one-way proposition for Boeing. Used to multi-year time periods for researching a problem, the team at Boeing only had a few months to help the Callaway team.
Crouch pointed to the way Callaway uses "prototyping and how it allows them to make pretty rapid decisions” as a valuable educational tool for his team, which included engineers Harrison Chau and Adam Clark. “It was really interesting drawing parallels between the problems of a golf club and the problems of an airplane,” Clark said. “There are a lot of similarities and a lot of differences. The physics are always the same.”
Evan Gibbs, Callaway’s senior manager of R&D for woods, said Boeing’s team learned quickly how hard his job is. “They were actually kind of blown away by the constraints that our problem had,” Gibbs said. “It’s a very different process for them, but I think it’s one of the things they liked, the idea of getting their guys to think faster, maybe not having every possible bit of data before we make a decision, put them out of their comfort zone a little bit.”
The key result of the cooperation was a feature on the front part of the crown designed to create selective turbulence in an effort to reduce aerodynamic drag. “It was easier to make it worse than to make it better,” Gibbs said. Studying the problem with Boeing’s input via computational fluid dynamics led to the shape of and location of what’s called a trip-step.
“This is aggressively forward in order to try to trip the flow before it separates,” Crouch said.
This area of the crown is where much of the research is focused these days from others, too. For example, Ping has moved its turbulators even more forward to help with this idea, and even the subtle shape of the curve where the crown and face meet is an important region.
The challenge is to marry the aerodynamic benefits without sacrificing the decreased spin and better energy transfer from a lowered center of gravity. Occassionally, aerodynamics and performance butt heads. What Callaway and Boeing learned together is how to compromise. Like with Boeing’s efforts to improve fuel efficiency and emissions on its airplanes through better aerodynamics, the future for driver design, Gibbs said, isn’t necessarily just about making big things move through the air faster.
“Rather than making this faster,” he said, “it might be how do we maintain the aerodynamic efficiency and have a bigger face or with this other type of geometry that has other benefits.”
It also might be the case that golf finds itself appealing to other industries for new ideas. What’s certainly true is that golf’s technological challenges have plenty of appeal to other engineers. Boeing’s Crouch and Clark say they both have taken up the game as a result of the work done with Callaway on the XR16. It also provided perhaps a more direct level of job satisfaction.
“Sure, most people end up on an airplane and they benefit from it but they don’t really have an appreciation for it,” Crouch said. “But when you do something with a consumer product like this, which ends up in the hands of a lot of people, they know that they’re benefiting from it because they’re receiving an incremental performance gain. That’s a pretty cool thing.
“It’s a little bit different from our day job.”