Simulation-Driven Aerodynamic Development of a High-Performance Motorcycle 2022-32-0112
Aerodynamics is of vital importance in the development of a high-performance super-sports motorcycle. It directly links with the product’s performance in terms of top speed, handling dynamics and user experience. The objective of this work is to achieve the best-in-class aerodynamic performance of a motorcycle using a comprehensive method, involving wind tunnel testing and CFD (computational fluid dynamics) modelling. Focus of the study is to understand the impact of aerodynamic forces on the ride comfort and handling (safety), in case of high-speed operation. In this work, a comprehensive CFD model is developed to assess the aerodynamic performance of a motorcycle. The model is validated with wind tunnel measurements – both for integral parameters, namely, coefficient-of-drag (????) and coefficient-of-pitching moment (????) and for a discrete parameter, which is coefficient-of-pressure (????), measured at 30 different locations on the motorcycle fairing. The coefficient-of-pressure is measured using pressure taps. A good agreement between the CFD model and wind tunnel measurement is observed. The results for integral quantities are within 5% error band, and for discrete parameters (????), the correlation is of the order of 98% between the measurement and model. We have analyzed about 150 design variations to achieve the best in class aerodynamic performance. Further, the CFD model is used to understand the transient forces experienced by rider head, because of vortex shedding from the wind shield (visor), head and its interaction. The study is conducted at two different heights of the rider head, with respect to wind shield, and at three different vehicle speeds. The results of this study, in terms of flow visualization and dynamic forces on the rider head and its frequency analysis are discussed. A vortex shedding from the helmet is observed at all speeds. Results are presented for two different position of the helmet with respect to visor.
