Measurements of the turbulent aerodynamic environment in road cycling

Engineering of Sport 15 - Proceedings from the 15th International Conference on the Engineering of Sport (ISEA 2024)

For the validity of wind tunnel and computational fluid dynamics (CFD) analyses, similarity parameters must be matched to accurately represent the aerodynamic environment. In cycling this not only means considering the Reynolds number, but also parameters such as surface roughness and upstream turbulence characteristics that are known to influence the flow around bluff bodies. Whilst the outdoor environment in which road cycling takes place is known to be highly turbulent, with intensities between 5 and 50%, the exact conditions experienced are not yet known. This is reflected in current wind tunnel and CFD analyses assessing cyclist and skinsuit aerodynamics where low turbulence flows are used with intensities in the order of 0.2 - 1.6%. To provide insight into the true aerodynamic environment present in road cycling, an instrumented bicycle has been developed and will be described alongside initial measurements of on-road turbulence.