Drag and lift measurements of solid sports balls in still air

Abstract

The following article considers lift and drag measurements of solid sports balls propelled through still air in a laboratory setting. The balls traveled at speeds ranging from 26 to 134 m/s with spin rates up to 3900 r/min. Light gates measured the speed and location of the balls at two locations from which lift and drag values were determined. Ball roughness varied from polished to rough surface protrusions, that is, seams as high as 1.5 mm. Lift and drag were observed to depend on speed, spin rate, surface roughness, and seam orientation. A drag crisis was observed on smooth balls as well as non-rotating seamed balls with seam heights less than 0.9 mm. The drag coefficient of approximately 0.42 was nearly constant with speed for spinning seamed balls with seam height greater than 0.9 mm. The still air drag coefficient of smooth balls was comparable to wind tunnel drag at low speeds (Re < 2 × 10⁵) and higher than wind tunnel results at high speeds (Re > 2 × 10⁵). The lift and drag coefficients of spinning balls increased with increasing spin rate. The lift coefficient of baseballs was not sensitive to ball orientation or seam height.

Keywords

Aerodynamics ball baseball drag lift seams softball

Get full access to this article

View all access options for this article.

References

Mehta

. Aerodynamics of sports balls. Annu Rev Fluid Mech 1985; 17: 151–189.

Alaways

Hubbard

. Experimental determination of baseball spin and lift. J Sport Sci 2001; 19: 349–358.

Awbi

Tan

. Effect of wind-tunnel walls on the drag of a sphere. J Fluid Eng 1981; 103(3): 461–465.

Cross

. Physics of baseball & softball. New York: Springer, 2011.

Briggs

. Effect of spin and speed on the lateral deflection (curve) of a baseball; and the magnus effect for smooth spheres. Am J Phys 1959; 27(8): 589–596.

Alam

Smith

et al . A study of baseball and softball aerodynamics. In: 9th conference of the International Sports Engineering Association (ISEA), Procedia Engineering, Lowell, MA, 9–12 July 2012, Elsevier.

Cross

Lindsey

. Measurements of drag and lift on tennis balls in flight. Sport Eng 2014; 17: 89–96.

Lieberman

Smits

Quintavalla

et al . Method for determining coefficients of lift and drag of a golf ball. Patent US6186002 B1, USA, 2001.

Martin

Smith

Kensrud

. Drag on sports balls using Doppler radar. In: 9th conference of the International Sports Engineering Association (ISEA), Procedia Engineering, Lowell, MA, 9–12 July 2012, Elsevier.

10.

Crowe

Elger

Roberson

. Engineering fluid mechanics. Hoboken, NJ: John Wiley & Sons, 2005.

11.

Achenbach

. Experiments on the flow past spheres at very high Reynolds numbers. J Fluid Mech 1972; 54(Pt 3): 565–575.

12.

Higham

Dennis

Glendinning

et al . The Princeton companion to applied mathematics. Princeton, NJ: Princeton University Press, 2015.

13.

Asai

Seo

Kobayashi

et al . Fundamental aerodynamics of the soccer ball. Sport Eng 2007; 10: 101–110.

14.

Maxworthy

. Experiments on the flow around a sphere at high Reynolds numbers. J Appl Mech 1969; 36(3): 598–607.

15.

Prandtl

. Essentials of fluid dynamics. New York: Hafner Publishing Company, 1952.

16.

Nathan

. The effect of spin on the flight of a baseball. Am J Phys 2008; 76(2): 119–124.

17.

Mehta

Pallis

. Sports ball aerodynamics: effects of velocity, spin, and surface roughness. Warrendale, PA: TMS, 2001, pp.185–197.

18.

Alaways

Mish

Hubbard

. Identification of release conditions and aerodynamic forces in pitched-baseball trajectories. J Appl Biomech 2001; 17: 63–76.

19.

Nathan

. Analysis of PITCHf/x pitched baseball trajectories, 9 December 2007, http://baseball.physics.illinois.edu/Analysis.pdf (accessed 1 September 2009).

20.

Kensrud

. Determining aerodynamic properties of sports balls in Situ. Master’s Thesis, Washington State University, Pullman, WA, 2010.

21.

Kensrud

Smith

Nathan

et al . Relating baseball seam height to carry distance. In: 7th Asia-Pacific congress on sports technology (APCST 2015): the impact of technology on sport VI, Barcelona, 23–25 September 2015. Amsterdam: Elsevier.

22.

Theobalt

et al . Pitching a baseball: tracking high-speed motion with multi-exposure images. In: ACM transactions on graphics (TOG): proceedings of ACM SIGGRAPH 2004, Los Angeles, CA, 8–12 August 2004. New York: ACM.

23.

Bearman

Harvey

. Golf ball aerodynamics. Aeronaut Quart 1976; 27(2): 112–122.

24.

Alaways

. Aerodynamics of a curve-ball: the Sikorsky/Lightfoot lift data. Eng Sport72008; 2: 429–436.

25.

Norberg

. Effects of Reynolds number and a low-intensity freestream. Gothenburg: Chalmers University of Technology, 1987.

26.

Charters

Thomas

. The aerodynamic performance of small spheres from subsonic to high supersonic velocities. Aeronaut Sci 1945; 12(4): 468–476.

27.

Watts

Ferrer

. The lateral force on a spinning sphere: aerodynamics of a curveball. Am J Phys 1987; 55(1): 40–44.

28.

Watts

Eric

. Aerodynamics of a knuckleball. Am J Phys 1975; 43(11): 960–963.

29.

Jinji

Sakurai

. Direction of spin axis and spin rate of the pitched baseball. Sport Biomech 2006; 5(2): 197–214.

30.

Harris

. College baseball receives offensive boost with flat-seam ball. Trib Total Media 2015; 12, http://triblive.com/sports/nationworldsports/8503869-74/ball-flat-season (accessed 25 July 2017).