Development of aerodynamic characteristics for motorcycles using scale model wind tunnel

In development of motorcycles, striking a good balance between aerodynamic performance and aesthetic design and shortening the development period are extremely important subjects for improvement of product value and cost efficiency.

There are various demands on aerodynamic performance of motorcycles, for example, the lower aerodynamic drag, aerodynamic stability, protective function against wind pressure on riders (hereinafter referred to as “wind protection”), low aeroacoustic noise and so on, for which various studies are made in every stage of development.

This paper presents an outline of the aerodynamic development of motorcycles by using wind tunnels, and shows the effectiveness of using a scale model wind tunnel by giving the following three examples of aerodynamic development.

1. 1
   The aerodynamic drag force of a 600 cc Supersports type motorcycle was reduced by 10% compared with the previous model by optimizing the shape of the fairings.
2. 2
   The aeroacoustic noise which riders suffer was reduced by 1.1∼3.7 dB for a 250 cc scooter.
3. 3
   The wind protection for a 1300 cc Sport/touring type motorcycle was developed by an in-depth survey of flow around riders.