The effect of geometry simplifications on aerodynamic cyclist posture optimization through numerical simulations

Cyclist aerodynamic performance can be optimized using Virtual Skeleton Methodology, adapting the rider posture, and evaluating its performance through numerical simulations, aiming to minimize overall aerodynamic drag. The goal of the present work is to understand if the outcome of this optimization procedure relies on the presence/absence of a bike or the specific leg orientation, when changing the rider's upper body position. The Generic Cyclist Model in time-trial position is used adapting the lower arm angle. The results show that the flow downstream of the cyclist remains relatively unaltered when removing the bike. The arm position that exhibits minimum aerodynamic drag is also independent of the presence of the bike and, in addition, of the specific leg orientation. This suggests that virtual cyclist posture optimization can be conducted without a bike and considering only a single leg position, which significantly simplifies the optimization process.