Aerodynamics of a golf ball with grooves

In this study, we investigate the aerodynamics of our newly designed golf ball that does not have dimples but grooves on its surface. The smooth part of its surface is approximately 1.7 times that of a golf ball with dimples. We directly measure the drag and lift forces on two versions of this golf ball in the ranges of real golf-ball velocity and rotational speed, and compare them with those of smooth and dimpled balls. At zero spin, the drag coefficient of our balls shows a rapid fall-off at a Reynolds number similar to that of a dimpled ball and maintains nearly a constant value (lower by 50% than that of smooth ball) at higher Reynolds numbers. At non-zero spin, the lift-to-drag ratio of one version of our ball is higher by 5%–20% in the supercritical Reynolds number regime than that of a dimpled ball, but it is lower otherwise. With the measured drag and lift forces, we predict the trajectories of our balls and compare them to those of smooth and dimpled balls for the same initial conditions. The flight distances of our balls are larger by 148%–202% than that of smooth ball and shorter by 6%–10% than that of a dimpled ball.