Aerodynamic Investigation of a Scooter in the University of Perugia Wind Tunnel

Two wheels vehicles for city use are common in Europe and particularly in Italy. In the last ten years a new concept of motorcycle has been introduced on the market: maxi-scooters. Maxi-scooters represent an evolution of the small size engine scooters (from 50 to 125 cc) that were created in the 50s for city use. In the last decade the market turned to bigger swept volumes, such as 250 and 500 cc. This category of motorcycles is aimed to a richer and more adult market, which needs a pleasant design, riding comfort and stability at higher speed. On the other hand, such vehicles for city use are passing a critical moment in terms of development of the engines, because of the stricter limits imposed by the environmental regulations and for the consequent and significant effects on performance. Road tests are no longer sufficient to reach optimal performance and the aerodynamic data of actual scooters with swept volumes over 250 cc need to be isolated, reproduced and measured in a wind tunnel. A wind tunnel and balance facility for motorcycle aerodynamic investigation, developed at the University of Perugia, is described in this paper. The development of the wind tunnel experimental set-up results from a research project between the University of Perugia and Piaggio S.p.A., one of the European leaders in scooters industry. Aerodynamic performances of a 500 cc scooter are presented in terms of aerodynamic forces and moments and related coefficients. The study is concentrated on the aerodynamic effects of important geometric changes that involve the front and the windshield.