Energy Savings for Freight Trains with Aerodynamically Optimized Loading Schemes

The research presented focuses on the potential of energy savings in intermodal freight rail transport by optimizing the loading scheme with regard to the aerodynamic drag.As part of this work, a parameter study was performed to quantify the effect of the loading gap size upstream and downstream of a test container on the drag of the test container itself.The resulting drag database was used to calculate the combined drag of different loading schemes and estimate the energy saving potential by reducing gaps.Within the scope of this work, wind-tunnel experiments were performed to investigate more than 200 model configurations at a yaw angle of 0° to provide a detailed look-up table for the aerodynamic drag.Measurements of selected loading schemes were repeated at a yaw angle of 5° to include crosswind effects and allow predictions for operational scenarios under realistic environmental conditions.The experiments were performed in the Crosswind Simulation Facility at DLR Göttingen at a Reynolds number of 5.0×10 5 .The outcome of this work is an estimation tool for drag related energy savings, which provides information for freight train operators to carry out a cost-benefit analysis and crucial wagon design aspects for aerodynamically optimized loading schemes.