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Check on Model Robustness: 2004 Tour de France. John Eric Goff Lynchburg College (Collaborator: Benjamin Lee Hannas North Carolina State University). Research Background. Ben Hannas (LC ’03) – Computational Physics Course Project (Spring ’03)
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Check on Model Robustness: 2004 Tour de France John Eric Goff Lynchburg College (Collaborator: Benjamin Lee Hannas North Carolina State University)
Research Background • Ben Hannas (LC ’03) – Computational Physics Course Project (Spring ’03) • Ideas from Giordano’s Computational Physics • Ben Modeled Two Stages of 2001 Tour de France for Project • After May ’03 Graduation, Ben and I Modeled Entire 2003 Tour de France • American Journal of Physics (May 2004)
Idea Behind Model • 21 Stage Profiles (Prolog + 20 Regular Stages) on Tour de France Web Site www.letour.fr • Turn Stage Profiles Into Sequence of Inclined Planes
Idea Visualization • Example – Stage 16 • 21 Hairpin Turns Through French Alps • Lance Armstrong Won Stage in 39’ 41” • Second Place – More Than ONE MINUTE SLOWER!
Reality to Stage Profile to Model • Turn Stage Profile into Sequence of Inclined Planes
Forces on Bicycle-Rider Combo • Weight: W = mg • Normal Force: FN = mg cosθ • Biker’s Force: Fb = Pb/v • Retarding Forces: FR = FD + Fr FD = CDAv2/2 (Drag Force) Fr = μrFN (Rolling Friction)
Model Parameters • Bicycle-Rider Mass: m = 77 kg • Coefficient of Rolling Friction: μr = 0.003 • Air Density: = 1.2 kg/m3 • Drag Coefficient ● Cross-Sectional Area: CDA = 0.35 m2 (θ ≥ 0, uphill) CDA = 0.25 m2 (θ < 0, downhill) (ample literature to support above values!)
Biker’s Power Output • Long Stages (2003 Model – 375W in place of 325W and 425W)
Biker’s Power Output • Short Stages – 0, 4, 16, and 19 (new for 2004 model!) • Reduce CDA by 20% for Drafting and Sleek Clothing (except stage 16)