Design and Construction of an Open-circuit Wind Tunnel with Specific Measurement Equipment for Cycling

In order to overcome resistance a cyclist has to deliver a total power output of which 90% is necessary to overcome the aerodynamic drag [1] and [2]. In order to perform research in this aerodynamic drag a wind tunnel has been built by the Belgium company Flanders’ Bike Valley. This wind tunnel is designed using classical design rules and with specific cycling requirements an open-circuit wind tunnel is designed. This wind tunnel, containing a test section in which two cyclist can be positioned in succession, contains three main measurement systems to investigate the aerodynamic drag of a cyclist. A balance is used for the measurements of aerodynamic forces acting on the model, a bikefitting test is included to have a perfect fit between cyclist and bike and finally a PIV system is installed to investigate the flow behaviour.