Aerodynamic optimization of freight-train operation: utilizing real-world and wind-tunnel experiments

The DLR FR8-LAB, a self-contained measurement-system equipped container has been used to take aerodynamic measurements on operational freight-trains. Transient pressure was measured with 330 sensors, and the global transient-forces and moments have been derived: aerodynamic drag – important for operational efficiency, and side-force and rolling moment – important for safety (the risk of overturning and derailment). LiDAR sensors, satellite navigation and thermal cameras are used to couple the aerodynamic measurements with the operating scenarios. Results have indicated significant differences in aerodynamic characteristics based on the operating conditions of freight trains: loading configuration, tunnels, crosswind – that have a significant impact on operating efficiency, and potentially the safety of operation. Together with wind-tunnel experiments performed in parallel – validated by this real-world data – recommendations for aerodynamic optimization can be made for freight-train and infrastructure operators and manufacturers.