ENVIRONMENTAL IMPACT OF AERODYNAMIC OPTIMIZATIONS AT HEAVY DUTY COMMERCIAL VEHICLES

摘要

The optimization of aerodynamic drag represents an important research area for the fuelrnconsumption reduction of heavy duty commercial vehicles. Today’s design of tractor-trailersrnin the European Community is significantly influenced by legislative boundary conditionsrnregarding the overall vehicle dimensions of the entire tractor and trailer arrangement. Thisrnfact in combination with the target of high transport efficiency leads to brick-shaped vehiclernouter geometries. In this way, the investigations of aerodynamic optimization at commercialrnvehicles are restricted to detail measures. Already performed investigations related to thisrntopic are discussed in literature, (6), (7).rnThe present publication treats the aerodynamic characteristics of general modifications at thernouter contour of heavy duty tractor-trailers regarding a reduction of drag resistance and thus arnpotential reduction of fuel consumption under steady state conditions on highway traffic. Thernresearch activities considered the European legislation for maximum vehicle dimensions andrnweight.rnA generic, virtual three dimensional computer aided design (3D-CAD) semi-trailer truck,rnwhich displayed the characteristics of market-typical vehicles, served as a basis for severalrnmodifications. All geometrical modifications at the virtual reference vehicle were investigatedrnand assessed by three dimensional computational fluid dynamics (3D-CFD) simulations. Tornget a better conclusion, the fuel consumption of each modified tractor-trailer was calculated inrnlongitudinal vehicle dynamics simulations.rnAs a result of the present work, different aerodynamic optimization measures were assessedrnand evaluated in comparison with the reference vehicle under consideration of the transportrnvolume. The research work demonstrates the big potential of aerodynamic optimization byrnapplication of general measures at the vehicle outer contour under compliance with thernEuropean legislative boundary conditions. As additional conclusion, the present work pointsrnout the different areas of a semi-trailer truck with respect to the potential of aerodynamicrnoptimization. The achieved improvements can lead to a reduction of fuel consumption, whichrnencloses both, optimized operating costs for carriers as well as reduced carbon dioxide (CO_2)rnemissions which support the intentions to environmental friendly road transport.