Elite Cycling Aerodynamics: Wind Tunnel Experiments and CFD

An experimental and numerical study of the aerodynamics of a cyclist in a typical racing position is presented. The study aims to provide understanding of the fundamental aerodynamic char-acteristics which underpin variations of drag with changes to rider shape and position. Experimentally, for a mannequin (with static crank/leg position) in a wind tunnel, velocity fields at sev-eral streamwise stations are measured by traversing the plane with a probe. The structure of the wake depends strongly on the leg position, is associated with the flow around the hips and can lead to large variations in the drag. Numerically, the same mannequin geometry is modeled and the flow simulated using a commercial fluid flow solver (ANSYS–CFX). Similar variation with crank angle of drag and flow topology is observed. Tran-sient flow simulations are found to match better with the mean velocity experimental measurements. It is found that for some crank angles, the wake is defined by a relatively strong vortex pair, and for others the wake is more oscillatory