It is known that the aerodynamic drag of a body is a contribution of shape (pressure drag) and friction (skin friction drag). In blunt or bluff and fat shapes the drag due to separation (pressure drag) is usually many times as high as the skin friction drag; for values of Reynolds number around 10^6, the skin friction drag is well established to be a “trigger” that, in certain combination of shape and attitude, can set in motion powerful mechanisms of global drag variation [1]. This paper focuses the attention on the influence of the speed on the aerodynamic drag of five different road motorcycles. Several experimental tests were performed in a wind tunnel [2] focusing the transient phase of rising wind speed. The observed variations of the drag depending on speed, that seem to be peculiarly evident for motorcycles, could be an opportunity to optimize aerodynamic performance, thus fuel consumption, depending on the vocation of the vehicle.
On the influence of the vehicle speed on the aerodynamic drag of road motorcycles
SCAPPATICCI, LORENZO;RISITANO, GIACOMO;BATTISTONI, MICHELE;DESIDERI, Umberto;GRIMALDI, Carlo Nazareno
2011
Abstract
It is known that the aerodynamic drag of a body is a contribution of shape (pressure drag) and friction (skin friction drag). In blunt or bluff and fat shapes the drag due to separation (pressure drag) is usually many times as high as the skin friction drag; for values of Reynolds number around 10^6, the skin friction drag is well established to be a “trigger” that, in certain combination of shape and attitude, can set in motion powerful mechanisms of global drag variation [1]. This paper focuses the attention on the influence of the speed on the aerodynamic drag of five different road motorcycles. Several experimental tests were performed in a wind tunnel [2] focusing the transient phase of rising wind speed. The observed variations of the drag depending on speed, that seem to be peculiarly evident for motorcycles, could be an opportunity to optimize aerodynamic performance, thus fuel consumption, depending on the vocation of the vehicle.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
