ON SIDE-WIND STABILITY OF HIGH-SPEED TRAINS

In order to achieve maximum performance and cost-efficiency, it is necessary to construct ever lighter trains. As the weight decreases, the impact of the aerodynamic forces increases, particularly for high-speed trains which are exposed to strong cross-wind gusts. Computational Fluid Dynamics (CFD), experimental data and Multi-Body Simulation (MBS) are used to detect the relevant parameters that are responsible for side-wind stability. Although reports of train accidents due to side wind dates back to the 19th century, fundamental studies on this issue have been published only in recent years. A detailed sensitivity study of the relevant parameters as aerodynamic axial rolling moment, aerodynamic lift, secondary spring stiffness of the bogie, position of the center of gravity and others will be presented. This sensitivity study shows the achievable side-wind stability of nowadays high-speed train concepts and allows to estimate the potential of improvements for future trains. In order to achieve a substantially higher side-wind stability, it is necessary to improve the aerodynamic performance of the car body in conjunction with an optimisation of the bogie design and shifting the center of gravity of the leading car towards the front. For the covering abstract see ITRD E125059.