Assessing the aerodynamics of an able-bodied cyclist and a shoulder-amputee cyclist by computer fluid dynamics

Abstract

This study aimed to analyse the aerodynamics by numerical simulations with computer fluid dy-namics of an able-bodied cyclist and a shoulder-amputee cyclist. An elite cyclist volunteered for this research; the cyclist was scanned with his competition gear and bicycle and the able-bodied and shoulder amputee 3D cyclists models were created. Numerical simulations were conducted between 1 m/s and 13 m/s (with increments of 1 m/s) with the fluent code. The effective surface area (ACd) varied between 0.38 and 0.59 m² for the able-bodied cyclist; whereas, for the shoulder-amputee, it varied between 0.29 m² and 0.62 m². The ACd difference between the able-bodied and the amputee ranged from 3% to 28% and the drag differed between 2% and 19%. The drag coefficient ranged between 0.55 and 0.84 for the able-bodied and from 0.45 and 0.92 for the shoulder-amputee. The drag ranged across the different velocities (1-13 m/s) from 0.36 N – 39.25 N for the able-bodied cyclist and for the shoulder-amputee between 0.38 N – 31.69 N. The two cyclist models presented significant differences and small effect sizes (t = 2.720; p = 0.019; d = 0.18). The linear regression models computed the drag differences between the able-bodied and the disabled cyclist; a significant relationship and very high effect sizes for drag (R² = 0.997; R²a = 0.995; SEE = 0.996; p < 0.001) were observed. This study allowed us to conclude that the shoulder-amputee cyclist presents a lower drag compared to the able-bodied one.