[en] A few riders have adopted a rather exceptional and more aerodynamic sprint position where the torso is held low and nearly horizontal and close to the handle bar to reduce the frontal area. The question arises how much aerodynamic benefit can be gained by such a position. This paper presents an aerodynamic analysis of both the regular and the low sprint position in comparison to three more common cycling positions. Computational fluid dynamics simulations are performed with the 3D RANS simulations and the transition SST k–ω model, validated with wind-tunnel measurements. The results are analyzed in terms of frontal area, drag coefficient, drag area, air speed and static pressure distribution, and static pressure coefficient and skin friction coefficient on the cyclist surfaces. It is shown that the drag area for the low sprint position is 24% lower than for the regular position, which renders the former 15% faster than the latter. This 24% improvement is not only the result of the 19% reduction in frontal area, but also caused by a reduction of 7% in drag coefficient due to the changed body position and the related changes in pressure distribution. Evidently, specific training is required to exert large power in the low sprint position.
Andrianne, Thomas ; Université de Liège - ULiège > Département d'aérospatiale et mécanique > Interactions Fluide-Structure - Aérodynamique expérimentale
Language :
English
Title :
CFD analysis of an exceptional cyclist sprint position
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Bibliography
Wilson DG (2004) Bicycling science, 3rd edn. MIT Press, Cambridge
Kyle CR, Burke ER (1984) Improving the racing bicycle. Mech Eng 106(9):34–45
Grappe G, Candau R, Belli A, Rouillon JD (1997) Aerodynamic drag in field cycling with special reference to the Obree’s position. Ergonomics 40(12):1299–1311
Lukes RA, Chin SB, Haake SJ (2005) The understanding and development of cycling aerodynamics. Sports Eng 8:59–74
Hanna RK (2002) Can CFD make a performance difference in sport? In: Ujihashi S, Haake SJ (eds) The engineering of sport 4. Blackwell Science, Oxford, pp 17–30
Defraeye T, Blocken B, Koninckx E, Hespel P, Carmeliet J (2010) Aerodynamic study of different cyclist positions: CFD analysis and full-scale wind-tunnel tests. J Biomech 43(7):1262–1268
Defraeye T, Blocken B, Koninckx E, Hespel P, Verboven P, Nicolai B, Carmeliet J (2014) Cyclist drag in team pursuit: influence of cyclist sequence, stature, and arm spacing. J Biomech Eng ASME 136(1):011005
Blocken B, Defraeye T, Koninckx E, Carmeliet J, Hespel P (2013) CFD simulations of the aerodynamic drag of two drafting cyclists. Comput Fluids 71:435–445
Blocken B, van Druenen T, Toparlar Y, Malizia F, Mannion P, Andrianne T, Marchal T, Maas GJ, Diepens J (2018) Aerodynamic drag in cycling pelotons: new insights by CFD simulation and wind tunnel testing. J Wind Eng Ind Aerodyn 179:319–337
Blocken B (2014) 50 years of computational wind engineering: past, present and future. J Wind Eng Ind Aerodyn 129:69–102
Griffith MD, Crouch T, Thompson MC, Burton D, Sheridan J, Brown NAT (2014) Computational fluid dynamics study of the effect of leg position on cyclist aerodynamic drag. ASME J Fluids Eng 136(10):101105
Fintelman DM, Hemida H, Sterling M, Li FX (2015) CFD simulations of the flow around a cyclist subjected to crosswinds. J Wind Eng Aerodyn 144:31–41
Crouch TN, Burton D, LaBry ZA, Blair KB (2017) Riding against the wind: a review of competition cycling aerodynamics. Sports Eng 20(2):81–110
Mannion P, Toparlar Y, Blocken B, Hajdukiewicz M, Andrianne T, Clifford E (2018) Improving CFD prediction of drag on paralympic tandem athletes: influence of grid resolution and turbulence model. Sports Eng 21(2):123–135
Beaumont F, Taiar R, Polidori G, Trenchard H, Grappe F (2018) Aerodynamic study of time-trial helmets in cycling racing using CFD analysis. J Biomech 67:1–8
Blocken B (2018) LES over RANS in building simulation for outdoor and indoor applications: a foregone conclusion? Build Simul. 10.1007/s12273-018-0459-3
Dal Monte A, Leonardi LM, Menchinelli C, Marini C (1987) A new bicycle design based on biomechanics and advanced technology. Int J Sport Biomech 3:287–292
Zdravkovich MM, Ashcroft MW, Chisholm SJ, Hicks N (1996) Effect of cyclist’s posture and vicinity of another cyclist on aerodynamic drag. In: Haake S (ed) The engineering of sport. Balkema, Rotterdam, pp 21–28
Jeukendrup AE, Martin J (2001) Improving cycling performance: how should we spend our time and money. Sports Med 31(7):559–569
Defraeye T, Blocken B, Koninckx E, Hespel P, Carmeliet J (2010) Computational fluid dynamics analysis of cyclist aerodynamics: performance of different turbulence-modelling and boundary-layer modelling approaches. J Biomech 43(12):2281–2287
Defraeye T, Blocken B, Koninckx E, Hespel P, Carmeliet J (2011) Computational fluid dynamics analysis of drag and convective heat transfer of individual body segments for different cyclist positions. J Biomech 44(9):1695–1701
Crouch TN, Burton D, Brown NAT, Thomson MC, Sheridan J (2014) Flow topology in the wake of a cylist and its effect on aerodynamic drag. J Fluid Mech 748:5–35
Blocken B, Toparlar Y (2015) A following car influences cyclist drag: CFD simulations and wind tunnel measurements. J Wind Eng Ind Aerodyn 145:178–186
Fintelman DM, Sterling M, Hemida H, Li FX (2014) The effect of crosswinds on cyclists: an experimental study. Eng Sport 10 Procedia Eng 72:720–725
Barry N, Burton D, Sheridan J, Thompson M, Brown NAT (2015) Aerodynamic drag interactions between cyclists in a team pursuit. Sports Eng 18(2):93–103
Barry N, Burton D, Sheridan J, Thompson M, Brown NAT (2016) Flow field interactions between two tandem cyclists. Exp Fluids 57(12):181
Blocken B, Toparlar Y, Andrianne T (2016) Aerodynamic benefit for a cyclist by a following motorcycle. J Wind Eng Ind Aerodyn 155:1–10
Mannion P, Toparlar Y, Blocken B, Clifford E, Andrianne T, Hajdukiewicz M (2018) Aerodynamic drag in competitive tandem para-cycling: road race versus time-trial positions. J Wind Eng Ind Aerodyn 179:92–101
Mannion P, Toparlar Y, Blocken B, Clifford E, Andrianne T, Hajdukiewicz M (2018) Analysis of crosswind aerodynamics for competitive handcycling. J Wind Eng Ind Aerodyn 180:182–190
Artec Europe (2017) Artec Eva, 3D scanners. https://www.artec3d.com/3d-scanner/artec-eva. Accessed 22 May 2017
Gore M (2016) Personal communication with sensor manufacturer
Barlow JB, Rae WH, Pope A (1999) Low-speed wind tunnel testing, 3rd edn. Wiley, New York
Franke J, Hellsten A, Schlünzen H, Carissimo B (2007) Best practice guideline for the CFD simulation of flows in the urban environment, COST Action 732: quality assurance and improvement of microscale meteorological models, Hamburg, Germany
Tominaga Y, Mochida A, Yoshie R, Kataoka H, Nozu T, Yoshikawa M, Shirasawa T (2008) AIJ guidelines for practical applications of CFD to pedestrian wind environment around buildings. J Wind Eng Ind Aerodyn 96(10–11):1749–1761
Casey M, Wintergerste T (2000) Best practice guidelines. ERCOFTAC special interest group on “quality and trust in industrial CFD”, ERCOFTAC
Tucker PG, Mosquera A (2001) NAFEMS introduction to grid and mesh generation for CFD. In: Wilson DG (ed) NAFEMS CFD working group, R0079, 2004. Bicycling science, 3rd edn. MIT Press, Cambridge
Menter FR, Langtry R, Volker S (2006) Transition modelling for general purpose CFD codes. Flow Turbul Combust 77(1):277–303
ANSYS Fluent (2013) Release 15.0, theory guide. ANSYS Inc, Canonsburg
Blocken B (2015) Computational fluid dynamics for urban physics: Importance, scales, possibilities, limitations and ten tips and tricks towards accurate and reliable simulations. Build Environ 91:219–245
Crouch TN, Burton D, Thompson MC, Brown NAT, Sheridan J (2016) Dynamic leg-motion and its effect on the aerodynamic performance of cyclists. J Fluids Struct 65:121–137
Blocken B, van Druenen T, Toparlar Y, Andrianne T (2018) Aerodynamic analysis of different cyclist hill descent positions. J Wind Eng Ind Aerodyn 181:27–45
Blocken B, Toparlar Y, van Druenen T, Andrianne T (2018) Aerodynamic drag in cycling team time trials. J Wind Eng Ind Aerodyn 182:128–145
Grappe F, Candau R, Busso T, Rouillon JD (1998) Effect of cycling position on ventilator and metabolic variables. Int J Sports Med 19:336–341
Underwood L, Schumacher J, Burette-Pommay J, Jermy M (2011) Aerodynamic drag and biomechanical power of a track cyclist as a function of shoulder and torso angles. Sports Eng 14(2–4):147–154. 10.1007/s12283-011-0078-z
Fintelman DM, Sterling M, Hemida H, Li FX (2014) Optimal cycling time trial position models: aerodynamics versus power output and metabolic energy. J Biomech 47(8):1894–1898
Fintelman DM, Hemida H, Sterling M, Li FX (2015) The effect of time trial cycling position on physiological and aerodynamic variables. J Sports Sci 33(16):1730–1737
Fintelman DM, Sterling M, Hemida H, Li FX (2016) Effect of different aerodynamic time trial cycling positions on muscle activation and crank torque. Scand J Med Sci Sports 26(5):528–534
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