Crosswind Stability

Railway vehicles are endangered by strong crosswinds, catastrophic accidents having already occurred in the history of railway transportation. This problem, aggravated by the continuous improvement of the light­weight characteristics of modern rolling stock, has eventually become a neuralgic point in the design and homologation of vehicles.

Accordingly, the project NGT includes a joined work package on this topic, in which DLR-Institute of Aerodynamics and Flow Technology contributes the aerodynamic design of the NGT including windtunnel measurements.

At DLR-RM, the research is focussed on the effects of the aerodynamic forces on the running safety of the railway vehicle. In par­ticular we work on three fronts:

• Models for a very accurate representa­tion of the unsteady wind loads are pre­pared, in order to avoid over-conserva­tive and far-from-reality wind loads to be considered in the design stage, see figure below.
• Advanced probabilistic methods for the risk analysis are developed and elabo­rated up to the homologation norm level.
• Countermeasures at the vehicle level, that may be based on active suspen­sion con­cepts, are studied and tested by simula­tion.

Stochastic wind crosswind velocity for running safety analysis (Related CFD results of the DLR-Institute of Aerodynamics and Flow Technology are given for visualisation.)