DLR measurement container delivers insights into freight train aerodynamics
December 9, 2024 | FR8-LAB: piggybacking across Europe
DLR measurement container delivers insights into freight train aerodynamics
FR8-LAB: a container full of high-tech
The FR8-LAB is a special DLR measurement container providing comprehensive, automated data on the aerodynamics of freight trains for the first time. The aim of the research is to make rail freight transport faster, more energy-efficient and safer.
While travelling by rail, the FR8-LAB's sensors measure the pressure, acceleration and vibration acting on the container. Infrared cameras and laser-based sensors perceive the environment.
DLR's FR8-LAB measuring container has travelled several thousand kilometres across Europe in recent months, gathering data to explore how optimised train formations can reduce energy consumption.
The FR8-LAB is a special DLR shipping container designed for measurement purposes, collecting automated data on the aerodynamics of freight trains.
The container is equipped with several hundred high-tech sensors to measure pressure, acceleration and vibration.
The aerodynamics of freight trains affect energy consumption and safety, an increasingly critical factor as more goods are to be transported faster by rail.
Focus: Transport, rail transport research, mobility of the future
Over recent months, a unique measurement container developed by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) has travelled thousands of kilometres on freight trains across Europe. Its task is to collect comprehensive data on the aerodynamics of freight trains for the first time, using an automated process. DLR's 'FR8-LAB' container, its name combining the words 'freight' and 'laboratory', travelled from Denmark to Spain like any standard transport container. Almost everyone is familiar with freight trains like this, where wagon after wagon stretches out in long lines. They can be several hundred metres long, often with significant gaps between the containers. To better protect the environment and ease the burden on road networks, an increasing volume of freight is expected to move by rail in the future. Achieving this requires making rail freight transport more attractive again, and key to this is faster, more flexible operations – posing challenges for vehicles, infrastructure and operators alike.
"The faster freight trains travel, the more critical their aerodynamics become," explains James Bell from the DLR Institute of Aerodynamics and Flow Technology in Göttingen. "In simple terms, when their speed doubles, aerodynamic drag quadruples. This significantly affects energy consumption of freight trains, but also safety. For the first time, the FR8-LAB allows us to analyse these factors in detail."
High-tech sensors on the move for tomorrow's freight transport
The FR8-LAB, developed by DLR, is the only one of its kind in Europe. From the outside, it looks like an ordinary transport container, distinguished only by its labelling. Inside, however, it houses sophisticated sensor technology. Several hundred sensors measure the pressure, acceleration and vibration acting on the container during its journey. Infrared cameras and laser-based sensors detect the environment, including the speed and distance of the FR8-LAB from surrounding containers, tunnels, noise barriers and other trains. The DLR team can monitor the high-resolution data remotely in real time. A combination of batteries and solar cells mounted on the container's roof supplies the necessary power.
"The major advantage of the FR8-LAB is its ability to be transported like a normal container, 'piggybacking' on standard container wagons. This eliminates the need for a special licence, allowing cost-effective and straightforward testing under real-world rail conditions over long distances. The results are exciting, comprehensive datasets that have not been available in this form before," says Bell. The DLR team then compares this data with simulations and wind tunnel tests conducted on freight train models.
Optimising wagon order to save energy
Initial findings indicate that aligning freight train wagons without large gaps significantly improves aerodynamic efficiency. Traditionally, freight trains have been assembled by hand, with limited flexibility. Digitalisation in rail transport – especially through automated, digital coupling systems for wagon arrangement – could enhance this process. "From an aerodynamic standpoint, smaller gaps of up to one metre have minimal impact, but larger gaps significantly increase drag. By improving wagon alignment, energy savings in the double-digit percentage range are achievable," summarises DLR expert Bell.
Ensuring safety even at high speeds
Faster freight trains will bring changes not only to energy consumption but also to safety. Aerodynamic effects such as the slipstream – the air suction created by a train passing through a station – are well understood for passenger trains but less so for faster-moving freight trains with varied wagon arrangements. Similarly, the increase in pressure when a freight train enters a tunnel is also not precisely known. Large gaps between individual wagons can exacerbate pressure fluctuations at high speeds, which can strain infrastructure like emergency exits, lighting and ventilation systems. "The FR8-LAB data enables us to investigate these issues in detail, advancing our research and supporting enquiries from the rail industry," Bell concludes. The FR8-LAB could eventually be adapted for use in road transport, offering insights into aerodynamic challenges for trucks.
Financed by the European Union. However, the views and opinions expressed are solely those of the author(s) and do not necessarily reflect those of the European Union. Neither the European Union nor the funding authority accepts responsibility for the content.
