Analysis of the aerodynamic performance of truck semi-trailers

Abstract In the last time, trucks have shown a very high interest in terms of their technical and fuel consumption performance. Prioritizing the phenomenon of having trucks that transport as much, as quickly and as economically as possible, this represent a new challenge for industry and engineering, which are in continuous development. The attempt to create a bridge as stable as possible between technical and consumer performance is supported by the multitude of areas that, based on studies and experimental trials, allow optimization without interfering, substantially, with the actual transport of the goods (loading capacities and transport). The main objective of this paper is to present the possibility of improving the aerodynamic performance of trucks, focusing on semi-trailers. For this study, a truck modelled at one to one scale was used, whose aerodynamic performance was verified in the virtual environment (CFD–Computational Fluid Dynamics); this environment has the possibility to test several geometric models without requiring the layout of a vehicle in physical form. To check the performance, a basic model was created, a conventional truck (tractor unit with semi-trailer), to which various semi-trailer modifications were made, such as: total and partial coverage of the side areas, idea to create a more aerodynamic profile of the semi-trailer in the back and the addition of fairings under the platform (underbody of the semi-trailer). The results describe the impact these elements have and allow the visualization of the possible future profile that is as aerodynamic as possible for semi-trailers (therefore also for trucks) from both theoretical and technical point of view. Through the proposed improvements the capacity and the transport of the goods is not affected, in a significant way so it can be said that there is the possibility of implementation in the industry.