Development of a novel variable semi-trailer body for air drag-, CO ₂ -emissions-and costs-reduction

The paper treats the creation of a variable curtain sider trailer prototype for long-distance haulage and the operation at a carrier for assessment and evaluation in view of fuel consumption and operational costs reduction potential. The new, patented technology enables a variable adjustment of the trailer body geometry for improvement of aerodynamic drag and provides required transportation volume at the same time. Project targets contain a verification of simulation results regarding fuel consumption and CO ₂ emissions reduction, as well as findings from practical use. The gathered data and information represent a basis for further industrial research. An aerodynamically unfavorable shape and a relatively high drag resistance characterize heavy duty commercial vehicles. Especially in long distance haulage, the air drag represents a significant influencing factor of the fuel consumption, the CO ₂ emissions, and the operational costs. Because the geometrical dimensions are limited by law, aerodynamic modifications have been restricted to detailed measures so far. Modifications of the general body shape lead to disadvantages regarding the transportation volume, which influences the transportation efficiency negatively. Basis of the present project represents the patent application EP2570283 (“Variable body geometry for commercial vehicles”, patent application document number: AT-EP11181175.8, 2011). This patent describes a novel approach of a variable body geometry for heavy duty trailer to enable both, an advantageous aerodynamic shape and enough transportation space on demand. Simulation by use of computational fluid dynamics has shown that the potential fuel consumption reduction reaches 5%, which corresponds with up to 2 liter per 100 km save of fuel. The project includes the design and development of a novel technology for a variable long-distance trailer. The variable shape enables both, a reduction of air drag and the provision of sufficient transportation volume. In case of empty trips or trips with reduced space requirements, the outer shape of the trailer is modified by lowering the roof line and tapering the side walls. This leads to a significant reduction of air drag. In case of high volume freight, the shape of the trailer remains in its original positions. The variability of the outer couture also supports loading processes.