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The application of crash durable structural adhesives in modern cars design, to improve the driving durability, the overall vehicle stiffness, the crash resistance and to make real light weight constructions feasible is significantly gaining in importance. 1-component systems are already introduced in the market and used in automotive industries. Usually the use of these bonds in automotive industries is limited by a relatively low wash off resistance in the pre-treatment tanks of the paint shop. If no additional actions are taken, there is a severe risk of wash off of the adhesives up to the partial loss in functionality. Respectively contamination of the pre-treatment tanks and aftereffects damage the surface of the coated cars. To avoid wash off a thermal process (oven) to pre-gel the adhesive in the flanges of the Body-In-White (BIW)- bodies before entering the pre-treatment utility is necessary. This is a save but cost intensive solution.

While hybrid-electric powertrain features such as regenerative braking and electric driving can improve the fuel economy of a vehicle significantly, these features may also have a considerable impact on driving dynamics. That is why extra effort is necessary to ensure safety and comfort that customers usually expect from a conventional vehicle. The purpose of this paper is to initiate a discussion regarding different drivetrain concepts, necessary changes in chassis systems, and the impact on vehicle dynamics. To provide input to this essential discussion, braking and steering systems, as well as suspension design, are analyzed regarding their fit with hybrid systems. It is shown how an integration of hybrid technology and chassis systems benefits vehicle dynamics and why “by-wire” technology is a key enabler for safe and comfortable hybrid-electric vehicles.

Digital radio broadcast systems, like HD-Radio™ and Satellite Radio, provide crystal clear sound. However, since they are essentially bits and bytes, they could also be used for distributing traffic and weather information or any other supplementary information. Due to considerably enhanced compression techniques, digital broadcast systems could also carry surround sound, which significantly improves the sound perception. Integration of the digital tuners in an automotive environment are mainly through MOST ring topologies, which allow flexibly adding different tuner modules depending on customer preferences and standards used in different markets. This paper aims at providing a more detailed insight into the aforementioned trends and developments, with a specific focus on premium segment automobiles.

A specific objective of the European Mg-Engine project is to qualify at least two die cast Mg alloys with improved high temperature properties, in addition to satisfactory corrosion resistance, castability and costs. This paper discusses the selection criteria for high temperature alloys leading to four candidate alloys, AJ52A, AJ62A, AE44 and AE35. Tensile-, creep- and fatigue testing of standard die cast test specimens at different temperatures and conditions have led to a very large amount of material property data. Numerous examples are given to underline the potential for these alloys in high temperature automotive applications. The subsequent use of the basic property data in material models for design of automotive components is illustrated.

The Deep Orange program is a concept vehicle development program focused on providing hands-on experience in design, engineering, prototyping and production planning as part of students’ two-year MS graduate education. Throughout this project, the team was challenged to create innovative concepts during the ideation phase as part of building the running vehicle. This paper describes the usability studies performed on two of the vehicle concepts that require driver interaction. One concept is a human machine interface (HMI) that uses a holographic companion that can act as a concierge for all functions of the vehicle. After creating a prototype using existing technologies and developing a user interface controlled by hand gestures, a usability study was completed with older adults. The results suggest the input method was not intuitive. Participants demonstrated better performance with tasks using discrete hand motions in comparison to those that required continuous motions.

A top-of-the-range car customer not only expects exceptional vehicle design and quality but also a driving experience, which is out of the ordinary. Very harmonious interaction between vehicle dynamics and the steering system is required to offer clients such a consistent driving experience through generations of vehicle models. In this paper the basic properties of a premium driving experience are explored. It is shown that outstanding handling limits are a prerequisite, although most customers never experience such driving situations. In fact, on-center behavior is most crucial in enabling clients to experience part of premium driving performance, and the steering system is the key factor in delivering appropriate feedback to the driver by means of steering torque. Development procedures are presented to achieve the goals described above.

In a consortium of European industrial partners and research institutes, a combination of industrial development and scientific research was organised. The objective was to improve the catalytic NOx conversion for lean burn cars and heavy-duty trucks, taking into account boundary conditions for the fuel consumption. The project lasted for three years. During this period parallel research was conducted in research areas ranging from basic research based on a theoretical approach to full scale emission system development. NOx storage catalysts became a central part of the project. Catalysts were evaluated with respect to resistance towards sulphur poisoning. It was concluded that very low sulphur fuel is a necessity for efficient use of NOx trap technology. Additionally, attempts were made to develop methods for reactivating poisoned catalysts. Methods for short distance mixing were developed for the addition of reducing agent.

Efficiency and dynamic behavior of a vehicle are strongly affected by its weight. Taking into consideration comfort, safety and emissions in modern automobiles, lightweight design is more of a challenge than ever in automotive engineering. Materials development plays an important role against this background, since significant weight decrease is made possible through the substitution of high density materials and more precise adjustment of material parameters to the functional requirements of components. Reinforced light metals, therefore, offer a promising approach due to their high strength to weight ratio. The paper gives an overview on matrix and reinforcement structures suited for the high volume output of the automotive industry. Further analytical and numerical approaches to describe the strengthening effects and the good mechanical characteristics of these composite materials are presented.

This study inquired into perceived attributes of car interior noise and correlating psychoacoustic parameters. Auditory assessments of a total of 29 vehicles were performed during cruise and acceleration in two independent road tests. Four perceptual dimensions were found to determine the sound evaluations: comfort/loudness, sportiness, harshness, and timbre. A regression model was used to predict comfort/loudness from sound level, roughness, sharpness and speech intelligibility (SVI). Instrumental assessments of engine roughness demonstrated to predict harshness to a large extent. Sportiness was substantially correlated with the increase of engine sound level due to load change. The latter finding was further examined in a third experiment, using sound synthesis in a test vehicle.

Automotive clear coats have a broad field of requirements to fulfill, e.g. weathering stability, stone chipping, chemical resistance, scratch resistance, and have to show a brilliant surface appearance. Beside this, the paint and repair process for high volume car manufacturing must be fulfilled with respect to costs and the environment. From the development point of view of a car manufacture interactions between these properties and the critical way of understanding and describing the value for the customer is shown. The conclusion of this scenario and a detailed benchmark study of different new clear coats guide to the development of the ‘Next generation’ of powder clear coats.

Currently, the aerodynamic development of a car concentrates on steady state aerodynamic forces. Development is mainly performed in wind tunnels with very low turbulence. On the road we find other boundary conditions. Natural wind, other cars and trucks influence the yawing moment and the side force. During acceleration and deceleration the vehicle speed is not constant, the effect of unsteady aerodynamic forces is especially important and can not be neglected. The approach to measure unsteady effects is to use a wind tunnel that has the capability to produce unsteady flow and in addition to instrument a car to drive under natural windy conditions. The wind tunnel, with its reproducible conditions, allows measurements to be made with well defined frequencies of the approaching flow. This is important since the aerodynamic forces are not sensitive to all frequencies in the same way. One way to increase driving comfort is to reduce these forces at specific frequencies.

Future catalyst systems need to be highly efficient in a limited packaging space. This normally leads to a design where the flow distribution, in front of the catalyst, is not perfectly uniform. Measurements on the flow test bench show that the implementation of perforated foils for the corrugated and flat foils has the capability to distribute the flow within the channels in the radial direction so that the maximum of the given catalyst surface is of use, even under very poor uniformity indices. Therefore a remarkable reduction in back pressure is measured. Emission results demonstrate cold start improvement due to reduced heat capacity. The use of LS - structured ( Longitudinal structured ) corrugated foils creates a high turbulence level within the single channels. The substrate lights-up earlier and the maximum conversion efficiency is reached more quickly.

Knowing the wheel forces on a vehicle under various circumstances and configurations is essential for its aerodynamic development. This becomes crucial when dealing with a racing car. This was the driving force for the initial research conducted in the BMW Aerodynamics Department [1] concerning the aerodynamic forces of an isolated 1:2 racing wheel. The latter were determined for various arrangements with the use of a system equipped with pressure transducers distributed on the wheel surface. While the pressure wheel is adequate for revealing flow structures surrounding it as well as highlighting its physics, it is nevertheless insufficient for the prediction of the wheel forces with high accuracy. As will be shown, this is mainly the consequence of the absent contribution of skin friction, the mathematical method engaged in post–processing and the restricted number of pressure transducers.

The requirement of the start of the internal combustion engine (ICE) not only at vehicle standstill is new for full hybrid electric vehicles in comparison to conventional vehicles. However, the customer will not accept any deterioration with respect to dynamics and comfort. ICE-starting-systems and -strategies have to be designed to meet those demands. Within this research, a method was developed which allows a reproducible maneuver-based analysis of ICE-starts. In the first step, a maneuver catalogue including a customer-oriented maneuver program with appropriate analysis criteria was defined. Afterwards, the maneuvers were implemented and verified in a special test bench environment. Based on the method, two sample hybrid vehicles were benchmarked according to the maneuver catalogue. The benchmarking results demonstrate important dependencies between the criteria-based assessment of ICE-starts and the embedded ICE-starting-system and -strategy.

The G-equation model was implemented in the commercial code ANSYS CFX and validated against experimental data in order to successfully simulate turbulent premixed combustion in internal combustion engines. The model is based on the level-set approach. Two transport equations are solved respectively for the G-scalar mean value, representing the local distance function from the time-averaged mean flame front, and its variance, correlated to the turbulent flame brush thickness. The model closure for tracking the flame front is based on an algebraic expression for the turbulent burning velocity. The composition of the reacted mixture is evaluated by coupling the code with flamelet libraries generated with the ANSYS CFX-RIF package by means of a reaction progress variable computed as a function of the G-related quantities.

Measurements from a Global Navigation System in conjunction with an Inertial Measurement Unit were recently introduced in different aerial and ground vehicles as an input to control vehicle dynamics. In automobiles this approach could help to further improve braking and / or stability control systems as information like velocity over ground and side slip angle becomes available. This paper presents the technical background, validation through test results and the evaluation of potential benefits of such an “INS/GPS” setup. As a result of the extended measuring capabilities a reduction in braking distance and a more effective stability control becomes possible. The results show an excellent performance that should be exploited in future automotive applications.

Efforts in aerodynamic optimization of road vehicles have been steadily increasing in recent years, mainly focusing on the reduction of aerodynamic drag. Of a car's total drag, wheels and wheel houses account for approx. 25 percent. Consequently, the flow around automotive wheels has lately been investigated intensively. Previously, the authors studied a treaded, deformable, isolated full-scale tire rotating in contact with the ground in the wind tunnel and using the Lattice-Boltzmann solver Exa PowerFLOW. It was shown that applying a common numerical setup, with velocity boundary condition prescribed on the tread, significant errors were introduced in the simulation. The contact patch separation was exaggerated and the flow field from wind tunnel measurements could not be reproduced. This investigation carries on the work by examining sensitivities and new approaches in the setup.

Unsteady aerodynamic flow phenomena are investigated in a wind tunnel by oscillating a realistic 50% scale model around the vertical axis. Thus the model is exposed to time-dependent flow conditions at realistic Reynolds and Strouhal numbers. Using this setup unsteady aerodynamic loads are observed to differ significantly from quasi steady loads. In particular, the unsteady yaw moment exceeds the quasi steady approximation significantly. On the other hand, side force and roll moment are over predicted by quasi steady approximation but exhibit a significant time delay. Part 2 of this study proves that a delayed and enhanced response of the surface pressures at the rear side of the vehicle is responsible for the differences between unsteady and quasi steady loads. The pressure changes at the vehicle front, however, are shown to have similar amplitudes and almost no phase shift compared to quasi steady flow conditions.

Unsteady aerodynamic flow phenomena are investigated in the wind tunnel by oscillating a realistic 50% scale model around its vertical axis. Thus the model is exposed to time-dependent flow conditions at realistic Reynolds and Strouhal numbers. Using this setup unsteady aerodynamic loads are observed to differ significantly from quasi-steady loads. In particular, the unsteady yaw moment exceeds the quasi-steady approximation by 80%. On the other hand, side force and roll moment are over predicted by quasi-steady approximation but exhibit a significant time delay. Using hotwire anemometry, a delayed reaction of the wake flow of Δt/T = 0.15 is observed, which is thought to be the principal cause for the differences between unsteady and quasi-steady aerodynamic loads. A schematic mechanism explaining these differences due to the delayed reaction of the wake flow is proposed.

Underbody aerodynamics has become increasingly important over the last three decades because of its vital contribution to improving a vehicle's overall performance. This was the motivation for the research conducted by BMW Aerodynamics, concerning the determination of the overall pressure distribution on the underbody of a series-production vehicle. Static pressure measurements have been taken under various test conditions. Real on-road tests were carried out as well as wind tunnel experiments under application of different road simulation techniques. The analyzed vehicle configurations include wheel rim-tire and body modifications. The results presented include surface pressure data, drag and lift coefficients, ride heights, pitch and roll angles. The acquired data is used to examine the underbody flow topology and determine how the diverse attempts to represent the real on-road conditions affect its pressure distribution.