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New Looks

Aerodynamic Architecture

Edited By Mike Stachura
Photos By Jim Herity
By Max Adler April 2008

The U.S. Golf Association has yet to limit the size or shape of dimples. And though their technological significance might be more overlooked than even that of the lowly tee, no facet of the game is more precisely engineered.

Yes, this is a story about dimples. Don't laugh. It's possible the largest performance gains left in golf will come from design improvements made to this basic element. In fact, there could be as much as 10 to 12 yards left for some balls to reach the USGA's Overall Distance Standard (ODS). Some theorize that even though companies might design golf balls that reach the USGA's Initial Velocity limit of 255 feet per second, those balls still fall short of the ODS limit of 320 yards. So how can ballmakers prevent their products from losing that whisper of steam down range? That's where dimples come in.

"It's not clear there's not some revolutionary idea to improve aerodynamics still out there," says John Axe, a Golf Digest Technical Panel member who has a Ph.D. in physics.

Dimples create a turbulent boundary layer of air around the ball that reduces the pressure difference between its front and rear as it flies. Typically, a shot loses 10 to 15 percent of its spin from impact until landing, and dimples can regulate that.

Consider one difference behind TITLEIST's two new balls, DT Carry and DT Roll (2 & 3). The Carry has 252 large dimples made for a higher flight. The Roll has 392 small dimples designed for a low flight that lands shallower to roll farther.

TAYLORMADE's team of new balls, including the TP Red, TP Black, Burner TP and Burner (1), are designed to have what the company calls "Low Drag Performance." The idea is to preserve spin on mis-hits for consistent distance by varying the dimple widths, depths and edge angles.

TOP-FLITE's tiny dimple-in-dimple idea in the Freak (4) is intended to help maintain lift by keeping the ball spinning longer.

However, the equation might not be that simple, says Martin Brouillette, Ph.D., Golf Digest Technical Panel member and professor of mechanical engineering at the University of Sherbrooke in Canada.

"There are no linear relationships with dimple sizes. Just as you can achieve identical lift and drag coefficients with differently shaped airplane wings, so too can you achieve identical flights with different dimples."

Says Steve Ogg, vice president of golf ball research and development at Callaway: "You want to maintain lift at low speeds without generating drag at high speeds. If the ball were always going fast, you'd want nothing but small dimples. But patterns are always a compromise."