Aerodynamic Design of a Competitive Freight Wagon

Abstract

The energy efficiency of rail freight by means of reduced drag can be increased significantly by technical and operational measures. Previous studies have shown that optimizing the car sequence can result in a drag reduction by at least a factor of 2 (Barkan, 2009). Consequently, an aerodynamic optimization of freight trains includes intelligent logistics concepts. Such concepts can be supported by means of providing priority lists for operational measures, resulting from experimental and numerical studies. But the aerodynamic resistance of a freight train with an optimized car sequence is still about 50% higher compared to a passenger train of the same length (Li, 2011). It is clear from this fact that there is a high potential for aerodynamic optimization of the individual wagon in the freight transport sector. As part of the FR8RAIL-Project in the framework of the EU joint undertaking Shift2Rail, an innovative freight wagon will be developed. A look at the existing freight wagon fleet shows that their design gives little consideration to aerodynamics. The entire contour of the existing wagons is determined by the laws of traditional steel construction. UIC (International Union of Railways) compatibility also greatly restricts the options for optimizing drag reduction which is the case for the air flow both underneath and along the sides of the vehicles. In contrast to previous approaches making modification to existing vehicles, a conceptually new approach offers far more options with regard to innovative aerodynamic optimization of single wagons and freight trains. This work needs to ensure the compatibility of the solutions with the logistics systems developed in the framework of the FR8RAIL project, for example by planning a rapid and low-cost assembly of the aerodynamic components. The investigations are performed concomitantly, so the safety-relevant aspects are considered continuously during the aerodynamic design of the freight wagon.