AeroSpeedGel by NAQI

Conclusion

The NAQI Aero Speed Gel uses vortex generators to enhance the turbulence in the boundary layer of the air flow across certain parts of a cyclist.


These enhanced turbulences lead to later flow separation and a corresponding smaller wake and lower drag.

Extensive wind tunnel testing showed a drag reduction of almost 4% when used on only the legs of a cyclist.

When also applied to the shoulder and arms of a triathlete a reduction in drag of almost 6% was obtainable.

 

REFERENCES

(1) Fage, A. & Warsap, J. H. (1930), The effect of turbulence and surface roughness on the drag of a circular cylinder. Aero. Red. Com. London, R & M. no. 1283.

(2) Singh, S. P. and Mittal, S. (2005), Flow past a cylinder: shear layer instability and drag crisis. Int. J. Numer. Meth. Fluids, 47: 75-98. doi:10.1002/fld.807

(3) Alam, Firoz & Chowdhury, Harun & Moria, Hazim & Mazumdar, Himani & Subic, Aleksandar. (2010). An experimental study of golf ball aerodynamics. 1-4. Proceedings of the 13th Asian Congress of Fluid Mechanics 17-21 December 2010, Dhaka, Bangladesh

(4) Drag of a sphere, NASA, https://www.grc.nasa.gov/www/K-12/airplane/dragsphere.html

(5) zgoren, Muammer & Dogan, Sercan & Okbaz, Abdulkerim & Sahin, Besir & Akilli, Huseyin. (2011). Investigation of surface roughness on the flow structure around a shere. Ankara international aerospace conference. September 2011

(6) Achenbach, E. (1971). Influence of surface roughness on the cross-flow around a circular cylinder. Journal of Fluid Mechanics, 46(2), 321-335.

(7) Crouch, Timothy N.; Burton, David; LaBry, Zach A. and Blair, Kim B. "Riding Against the Wind: a Review of Competition Cycling Aerodynamics." Sports Engineering (May 2017)

 

AUTHORS

First Author - Nikolaas Van Riet, cycling aerodynamics consultant, former head of the wind tunnel testing facility at Bike Valley, nikolaas.vanriet@gmail.com

Second Author - Greet Claes, Head of research & development at NAQI, g.claes@naqi.com