On the aerodynamic flow around a cyclist model at the hoods position
Tóm tắt
Aerodynamic flow around an 1/5 scale cyclist model was studied experimentally and numerically. First, measurements of drag force were performed for the model in a low-speed wind tunnel at Reynolds numbers from $$5.5 \times 10^{4}$$ to $$1.8 \times 10^{5}$$. Meanwhile, numerical computation using a large eddy simulation method was performed at three Reynolds numbers of $$1.1 \times 10^{4}$$, $$6.5 \times 10^{4}$$ and $$1.5 \times 10^{5}$$ to obtain the drag coefficients for comparison. Second, flow visualization was made in a water channel and the wind tunnel mentioned to examine the three-dimensional flow separation pattern on the model surface, which could also be realized from the numerical results. Finally, a wake flow survey based on the hot-wire measurements in the wind tunnel showed that in the near-wake region, the flow was featured with the formation of multiple streamwise vortices. The numerical results further indicated that these vortices were evolved from the separated flows occurred on the model surface.
Tài liệu tham khảo
Bandet JS, Perisol AG (1991) Random data analysis and measurement procedures, 2nd edn. Wiley, New York
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, Andrianne T (2018) Aerodynamic analysis of different cyclist hill descent positions. J Wind Eng Ind Aerodyn 181:27–45
Chen Q, Zhong Q, Qi M, Wang X (2015) Comparison of vortex identification criteria for planar velocity fields in wall turbulence. Phys Fluids 27(8):085101
Chowdhury H, Alam F (2014) An experimental investigation on the aerodynamic drag coefficient and surface roughness properties of sport textiles. J Text Inst 105(4):414–422
Crouch TN, Burton D, Brown NAT, Thompson MC, Sheridan J (2014) Flow topology in the wake of a cyclist and its effect on aerodynamic drag. J Fluid Mech 748:5–35
Crouch TN, Burton D, Thompson MC, Brown NAT, Sheridan J (2016a) Dynamic leg-motion and its effect on the aerodynamic performance of cyclists. J Fluids Struct 65:121–137
Crouch TN, Burton D, Venning JA, Thompson MC, Brown NAT, Sheridan J (2016b) A comparison of the wake structures of scale and full-scale pedaling cycling models. Procedia Eng 147:13–19
Debraux P, Grappe F, Manolova AV, Bertucci W (2011) Aerodynamic drag in cycling: methods of assessment. Sports Biomech 10:197–218
Defraeye T, Blocken B, Koninckx E, Hespel P, Carmeliet J (2010a) Aerodynamic study of different cyclist positions: CFD analysis and full-scale wind tunnel tests. J Biomech 43:1262–1268
Defraeye T, Blocken B, Koninckx E, Hespel P, Carmeliet J (2010b) Computational fluid dynamics analysis of cyclist aerodynamics: performance of different turbulence-modelling and boundary-layer modelling approaches. J Biomech 43:2281–2287
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 44:1695–1701
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 Trans ASME 136:011005-1
Griffith MD, Crouch TN, Thompson MC, Burton D, Sheridan J, Brown NA (2014) Computational fluid dynamics study of the effect of leg position on cyclist aerodynamic drag. J Fluids Eng 136(10):101–105
Hsu XY, Miau JJ, Tsai JH, Tsai ZX, Lai YH, Ciou YS, Shen PT, Chuang PC, Wu CM (2019) The aerodynamic roughness of textile materials. J Text Inst 110(5):771–779
Hucho WH, Sovran G (1993) Aerodynamics of road vehicles. Annu Rev Fluid Mech 25:485–537
Jeong J, Hussain F (1995) On the identification of a vortex. J Fluid Mech 285:69–94
Kyle CR, Burke E (1984) Improving the racing bicycle. Mech Eng 106:34–45
Li SR (2017) Investigation on wake structure of a cyclist model at the hoods position. Master Thesis, National Cheng Kung University, Tainan, Taiwan
Li SR, Miau JJ, Phung MV, Tsai ZX, Lin SY (2017) Investigation on wake structure of a cyclist model at the hoods position. In: The 14th Asian symposium on visualization, Beijing, 22–26 May 2017
Lighthill ML (1963) Introduction, boundary layer theory. In: Rosenhead L (ed) Laminar boundary layers, Chapter II. Oxford University Press, Oxford
Lukes RA, Chin SB, Haake SJ (2005) The understanding and development of cycling aerodynamics. Sports Eng 8(2):59–74
McMillan OJ, Ferziger JH (1979) Direct testing of subgrid-scale models. AIAA J 17:1340–1346
Miau JJ, Leu TS, Lin TW, Chou JH (1997) On vortex shedding behind a circular disk. Exp Fluids 23:225–233
Nicoud F, Ducros F (1999) Subgrid-scale stress modelling based on the square of the velocity gradient tensor. Flow Turbul Combust 62:183–200
Oggiano L, Sætran L, Løsetp S, Winther R (2007) Reducing the athlete’s aerodynamic resistance. J Comput Appl Mech 8(2):163–173
Oggiano L, Troynikov O, Konopov I, Subic A, Alam F (2009) Aerodynamic behavior of single sport jersey fabrics with different roughness and cover factors. Sports Eng 12(1):1–16
Parker PA, Morton M, Draper N, Line W (2001) A single vector force calibration method featuring the modern design of experiments. In: Proceedings of the 39th AIAA aerospace sciences meeting and exhibition, AIAA-2001-0170, Reno, NV
Phung MV (2017) Aerodynamic study of cycling hood position by using large eddy simulation methods. Master Thesis, National Cheng Kung University, Tainan, Taiwan
Roshko A (1993) Perspectives on bluff body aerodynamics. J Wind Eng Ind Aerodyn 49:70–100
Schlichting H (1979) Boundary-layer theory, 7th edn. McGraw-Hill, New York
Smagorinsky J (1963) General circulation experiments with primitive equations. Mon Weather Rev 91(3):99–164
Spohn A, Gillieron P (2002) Flow separations generated by a simplified geometry of an automotive vehicle. In: IUTAM symposium on unsteady separated flows, Toulouse, 8–12 April 2002
Taneda S (1978) Visual observations of the flow past a sphere at Reynolds numbers between 104 and 106. J Fluid Mech 85(1):187–192
Tennekes H, Lumley JL (1972) A first course in turbulence. MIT Press, Cambridge
Tsai ZX, Miau JJ, Chen TL, Lai YH, Wong H (2016) Balance design for drag measurement. In: The 11th international symposium on advanced science and technology in experimental mechanics, Ho Chi Minh, 1–4 Nov 2016