Computational Fluid Dynamics methodologies have been used to improve the design of Ducati High Performance Motorcycle in three different areas: the cooling system, the exhaust system and the air-box. As can be noticed by the results presented at the end of each section, for every design areas it has been possible to obtain reliable information which can be useful during the design process to better understand the thermo and fluid dynamic process involved. A multi-scale methodology has been applied for the analysis of heat exchangers. In the first part the finite volume analysis of the vehicle aerodynamics has been exploited in order to obtain reliable information on velocity distributions across the heat exchangers. It is clear from the analysis of the flow field that the airflow which crosses both thermal devices is extracted from the section between the bottom part of the windshield and the front wheel group. The complexity of the geometry close to the flow which crosses the thermal device has the greater effect on radiator efficiency, and it was found that, despite of its position, the oil radiator shows a lower efficiency of about 40 % compared to that of the water radiator for the same free stream velocity. This result is in part determined by the counter pressure which the engine and the air-box create behind the water radiator. The analysis performed with the distributed parameters model have allowed to investigate the effects of the velocity distributions on the thermal process throughout the thermal devices, and the time needed for the computations has been dramatically reduced by the simpler formulation of the model. A detailed analysis of the exhaust system has been made with particular emphasis to determination of proper flow parameters. Moreover, uniformity of velocity profiles and flow mixing have been evaluated, since they can greatly affect the performance of this component in terms of pollution emission and catalyst life. Useful indication about dependence of uniformity parameter with respect of pipes curvature has been found. The inlet flow at catalytic converter which follows a stronger pipe curvature presents a relatively large separated flow. It produces an undesiderable asymmetry on catalytic converters operative conditions. Moreover, the location of Lambda probe, where the flow results to have an optimal mixing, has been investigated. The upper zone of the common volume seems to be the best location for this probe. The frequency analysis of air-box has brought to identify the effects of this system to the engine dynamics behaviour. The obtained Power Density Spectrum have pointed out, in all cases, a peak value at f=130 Hz. Moreover, the horizontal cylinder produces its maximum pressure value almost similar at the two considered measurement locations, conversely, they are slightly more different for the vertical cylinder.
Application of CFD to thermo fluid dynamics design of high performance motorcycles
Development Trends of Motorcycles II, International Conference Development Trends of Motorcycles, 3 ; 16-38
2005
23 Seiten, 23 Bilder, 22 Quellen
Conference paper
English
Application of CFD to Thermo Fluid Dynamics Design of High Performance Motorcycles
British Library Conference Proceedings | 2005
|Chatter vibrations of high-performance motorcycles
Taylor & Francis Verlag | 2013
|Online Contents | 2001
Online Contents | 2010