Search Results

The use of sensors in advanced driver-assistance systems (ADAS) and autonomous vehicles has been accelerating over the past few years largely driven by regulatory and consumer interest in safety applications. These sensors help to prevent accidents and protect drivers by assisting with the monitoring, warning, braking, and steering tasks. As several unfortunate examples have highlighted these valuable systems can reduce safety if the sensors are not operating un-impaired. Planning for harsh weather environments is critical to the success of these systems. This study presents a fully automated workflow for an industrial side mirror geometry optimization for improved sensor performance under soiling conditions. The methodology includes CAD parametrization, multiphase simulation setup, intelligent design optimization and a detailed result analysis. All relevant aspects like external flow, geometrical fidelity and multiphase interaction are considered.

In aerodynamic development of ground vehicles, the use of Computational Fluid Dynamics (CFD) is crucial for improving the aerodynamic performance, stability and comfort of the vehicle. Simulation time and accuracy are two key factors of a well working CFD procedure. Using scale-resolving simulations, accurate predictions of the flow field and aerodynamic forces are possible, but often leads to long simulation time. For a given solver, one of the most significant aspects of the simulation time/cost is the temporal resolution. In this study, this aspect is investigated using the realistic vehicle model DrivAer with the notchback geometry as the test case. To ensure a direct and accurate comparison with wind tunnel measurements, performed at TU Berlin, a large section of the wind tunnel is included in the simulation domain. All simulations are performed at a Reynolds number of 3.12 million, based on the vehicle length.

Reducing energy consumption and emissions are ongoing challenges for the transport sector. The increased number of goods transports emphasize these challenges even more, as greenhouse gas emissions from these vehicles increased by 20 % between 1990 and 2013, in Sweden. One special case of goods transports is the transport of timber. Today in Sweden, around 2000 timber trucks transport around six billion ton kilometers every year. For every ton kilometer these vehicles use around 0.025 liter diesel, and there should exist large possibilities to reduce the fuel consumption and the emissions for these vehicles. Timber trucks spend most of their operation time travelling in speeds of around 80 km/h. At this speed aerodynamic drag contributes to around 30 % of the total vehicle resistance, which makes the aerodynamic drag a significant part of the energy consumption. One of the big challenges with timber trucks is that they travel unloaded half of the time.

Considerable amounts of the everyday goods transports are done using light trucks. In the last ten years (2005-2015), the number of light trucks has increased by 33 % in Sweden. The majority of these light trucks are fitted with a swap body and encounter the same problem as many other truck configurations, namely that several different manufacturers contribute to the final shape of the vehicle. Due to this, the aerodynamics of the final vehicle is often not fully considered. Hence there appears to be room for improving the aerodynamic performance. In this study the flow around a swap body fitted to a light truck has been investigated using Computational Fluid Dynamics. The focus has been on improving the shape of the swap body in order to reduce both the aerodynamic drag and fuel consumption, while still keeping it usable for daily operations.

Road transportation by trucks is the major part of the goods transportations system in the European Union (EU), and there is a need for increased fuel efficiency. While truck manufacturers already spend significant resources in order to reduce the emissions from their vehicles, most truck manufacturers do not control the shape of the trailer and/or swap bodies. These devices are usually manufactured by different companies that cannot consider the overall aerodynamics around the complete vehicle. By use of Computational Fluid Dynamics (CFD) and previous wind tunnel experiments, the flow around a simplified generic tractor-trailer model has been investigated. With better understanding of the flow features around the tractor with attached trailer or swap bodies, an improved design of the trailer and swap body can be achieved, which is the aim for the project.