Abstract
Research and/or Engineering Questions/Objective:
The paper treats the creation of a variable curtain sider trailer prototype for long-distance haulage and a timely limited operation at a carrier for assessment and evaluation of a potential reduction of fuel consumption and operational costs. The new, patented technology enables a variable adjustment of the trailer body geometry and provides required transportation volume at the same time. Project targets contain a verification of simulation results regarding fuel consumption and CO2 emissions reduction, as well as findings from practical use. The gathered data and information represent a basis for further industrial research.
Methodology:
- Design and layout of the mechanism, design of an electrical driven propulsion system for the mechanism
- Operation of the research trailer at a carrier, application of measurement equipment
- Analysis of the measurements, simulation of fuel consumption potential.
Results:
An aerodynamically unfavourable shape and a relatively high drag resistance characterize heavy duty commercial vehicles. Especially in long distance haulage, the air drag represents a significant factor of the fuel consumption, the CO2 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. This patent describes a novel approach of a variable body geometry of heavy duty trailer to enable both, an advantageous aerodynamic shape and enough transportation space on demand. Simulation by use of computational fluid dynamics have shown, that the potential fuel consumption reduction reaches 5%, which corresponds with about 2 litre per 100 km save of fuel.
Limitations of this study:
Although the simulation model is based on vehicle data, the verification on experimental data is a next step. Furthermore, for simplification of the vehicle model the following effects were not taken into account: The influence of engine speed on friction losses are kept constant and the impact of tire to road grip on driving performance was neglected.
What does the paper offer that is new in the field in comparison to other works by the author:
- Detailed design of the conceptual (patented) kinematics and detailed layout of the mechanism;
- Precise measurement results from daily use, cognitions from practical application at a carrier;
- Assessment and evaluation of the potential savings in fuel consumption, CO2 reduction and operational costs;
- Experiences from a prototype application as a basis for a further development.
Conclusion:
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.
KEYWORDS: Semi-trailer, variable body geometry, flow simulation, air drag reduction, CO2 emissions reduction, fuel efficiency