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Viewing 1 to 30 of 696
2014-04-01
Technical Paper
2014-01-1005
Helmut Brunner, Mario Hirz
Abstract Increasing urbanization, the growing degree of motorization and traffic performance in urban areas and environmental aspects like greenhouse gas emissions (GHG) are the motivation for a detailed analysis of personal individual mobility in urban areas, which is presented in this study. In the first step, the publication examines a study of market potential of new small and lightweight vehicle concepts. A mobility inquiry conducted in a mid-sized European city enables an estimation of the potential user groups for alternative vehicle concepts for individual urban traffic. In a second step, the CO2 reduction potential of urban car concepts is simulated for a generic vehicle fleet. This fleet consists of conventional vehicles of various classes (subcompact, compact, mid-sized …) as well as new lightweight urban car concepts. A novel vehicle concept for urban transportation will be presented as well.
2014-04-01
Journal Article
2014-01-0475
Joseph Cormier, Mark "Tony" Freund, Enrique Bonugli, Herbert Guzman
Performing a reconstruction of sideswipe interactions is difficult due to the lack of permanent crush sustained by the vehicles involved. Previous studies have provided insight into the forces involved in creating various types of damage for vehicle-to-vehicle interactions during a sideswipe interaction. However, these data may not be applicable to the interaction that occurs when a tractor-trailer steer tire is involved. As demonstrated in previous studies, steer tire interaction produces a unique pattern of markings on the struck vehicle by the protruding lugs (wheel stud) of the steer tire. These studies have demonstrated that the pattern of cycloidal marks created by the wheel lugs can be used to calculate the relative speeds of the vehicles. While this is helpful in understanding the relative motion of the vehicles, it does not provide information regarding the forces applied at the point of contact.
2013-03-25
Technical Paper
2013-01-0037
Felix Regin A., Manoraj Manimanoharan, Akepati Bhaskar Reddy, Prakash Nigam
Aerodynamic behavior of the vehicle changes dramatically when a vehicle is modified from a closed body to a convertible vehicle. Change in the flow behavior and its effect on the vehicle road load and consequently on the fuel economy have been studied systematically from a full vehicle closed model to a convertible vehicle model. The flow patterns and the flow velocities both inside and outside the vehicle are studied using commercial Computational Fluid Dynamics (CFD) solver Star CCM+. In this paper a modified cabriolet is analyzed and is compared with the closed roof production vehicle and the closed roof production vehicle with various windows open configurations. The vehicle drag coefficient and the air flow behavior inside the passenger cabin are compared. Theoretical calculations are also done to compare the changes in road load at different vehicle speeds. The result shows that the Cabriolet vehicle drag coefficient is about 32% higher than the closed roof production vehicle.
2013-01-09
Technical Paper
2013-26-0058
Carsten Stechert, K. C. Vora
India already has the highest concentration of megacities and urban growth continues. Together with an increasing need for individual mobility in particular, the Indian market demands new vehicle concepts. German lower-Saxony research centre of Automotive Engineering (NFF) and The Automotive Research Association of India (ARAI) together with representatives from the automotive industry develop a research roadmap to satisfy the future demand for metropolitan cars.
2012-09-10
Technical Paper
2012-01-1707
Trevor W. Miller, Wim Van Dam, Gary Parsons
New engine technologies are constantly being developed and introduced in order to meet increasing customer demands and government regulations. In many cases, improved engine oil performance is necessary to facilitate the implementation of new engine technologies. In order to meet increasing customer demands for performance, durability, and fuel economy, the engine builders are introducing hardware and operating cycles that place increasing demands on the engine oil. Each new North American Gasoline Engine Oil Performance Category has been developed with specific performance targets and improvements in mind. This paper will primarily focus on the initial steps in the development of engine oils for the GF-6 passenger car engine oil category in North America. GF-6 is scheduled to be introduced during the 1st quarter of 2015 and will supersede GF-5 and previous categories. It will also be backward compatible and will provide improved performance relative to GF-5 in many respects.
2012-06-13
Technical Paper
2012-01-1525
Hans Gruber, Jianmin Guan
There are various optimization tools available on the market and they are successfully used for improving vehicle component designs in terms of performance and light weight [6][7][9][10]. But when it comes to full vehicle optimization, optimization tools are only one aspect of the entire process. To build up a FEM Model for NVH analysis the assembly process and load case definition play an important role. Both steps are very complex and the chance to make mistakes is very high. After initial analysis the results has to be interpreted to understand the NVH behavior and detect optimization potential. Diagnostic tools could be used to determine modal or panel participation factors or do transfer path analysis. Then components or subsystems could be optimized using numerical optimization tools. For this step often super elements are used to reduce calculation time without losing too much of accuracy.
2012-04-16
Technical Paper
2012-01-0646
Bert Bras, Francisco Tejada, Jeff Yen, John Zullo, Tina Guldberg
Numerous studies have pointed out the growing need to assess the availability of water sources in numerous regions around the world as future forecasts suggest that water demands will increase significantly while freshwater resources are being depleted. In this paper, we highlight the difference between water use versus consumption and analyze the life-cycle water consumption of a car from material extraction through production, use, and final disposition/end of life and determine a car's water footprint using data from the EcoInvent database as well as data collected from literature sources. Although water use is typically metered at the factory level, water consumption (i.e., water lost through evaporation and/or incorporation into a material, part, and/or product) is much harder to quantify. As shown in this paper, the difference can be an order of magnitude or more.
2012-04-16
Technical Paper
2012-01-0725
Nickolas Vlahopoulos, Matthew Castanier, Nicholas Stowe, Eric Maes
In this paper a Multi-Level System (MLS) optimization algorithm is presented and utilized for the multi-discipline design of a ground vehicle track. The MLS can guide the decision making process for designing a complex system where many alternatives and many mutually competing objectives and disciplines need to be considered and evaluated. Mathematical relationships between the design variables and the multiple discipline performance objectives are developed adaptively as the various design considerations are evaluated and as the design is being evolved. These relationships are employed for rewarding performance improvement during the decision making process by allocating more resources to the disciplines which exhibit the higher level of improvement. The track analysis demonstrates how a multi-discipline design approach can be pursued in ground vehicle applications.
2012-04-16
Technical Paper
2012-01-0649
Shigeki Nitta, Yoshihisa Moriguchi
In previous Life Cycle Assessment (LCA) methods, environmental burden items to be analyzed, prior to a life cycle inventory analysis, were assumed as the main factors of environmental problems regardless of the product category. Next, the life cycle inventory analysis, in which the total amount of environmental burden items emitted during the life cycle of a product was calculated, and an environmental impact assessment were performed. The environmental impact assessment was based on the initially assumed environmental burden items. The process, in other words, was a particular solution based on this assumption. A general solution unconstrained by this assumption was necessary. The purpose of this study was to develop a general method of LCA that did not require such initially assumed environmental burden items, and to make it possible to perform a comprehensive environmental impact assessment and strategically reduce environmental burden of a product.
2012-04-16
Technical Paper
2012-01-0635
Heinrich Reister, Walter Bauer
In this paper the latest status of the Vehicle Thermal Management (VTM) simulation at the Mercedes-Benz Car Group is shown. First of all VTM is nowadays a routine simulation application and secondly it is embedded in a standard process which starts with the CAD data collection and ends with standard reporting of the simulation results and thirdly VTM is now an integrated simulation application in terms of VTM includes the classical underhood-underbody analysis, the analysis of electric/electronic components, the brake temperature analysis and last not least the thermal comfort of passengers. There is also a close link to the tests of vehicle hardware. Beside the operational simulation process there is a process installed which guarantees good quality of the results.
2012-04-16
Technical Paper
2012-01-0778
Zhengqi Gu, Xin Song, Yejie Jiang, Xu Gong
Realizable k-ε turbulence model has been used widely for engineering development. In this turbulence model, the default values of empirical coefficients such as C₂, σk and σε are obtained from some particular experiments. They are a good choice for most simulations-though may be not the best choice for simulating the aerodynamic characteristics of road vehicle. In order to improve the accuracy of simulation, a set of new empirical coefficients should be designed especially for simulating the aerodynamic characteristics of road vehicle. These empirical coefficients are found out by DoE (design of experiments) in this paper. Firstly the value range of empirical coefficients is decided by the laws that the aerodynamic force coefficients change with altering of empirical coefficients. Secondly 20 sets of empirical coefficients are obtained randomly by applying optimal Latin Hypercube method in Isight.
2011-10-06
Technical Paper
2011-28-0001
Frank Will, James Nicholas Davdison, Paul Couchman, David Bednall
The current automotive industry and todays car drivers are faced with every increasing challenges, not previously experienced. Climate Change, financial issues, rising fuel prices, increased traffic congestion and reduced parking space in cities are all leading to changes in consumer preferences and the requirements of modern passenger vehicles. However, despite the shift in the industry dynamics, the principal layout of a car hasn't changed since its invention. The design of a ‘conventional’ vehicle is still principally a matchbox with four wheels, one at each corner. The concept has served its purpose well for over 100 years, but such a layout is not suited to solving today's problems. To address the range of problems faced by the industry, a number of alternative commuting vehicles have been developed. Yet the commercialization of these ‘alternative’ vehicles has yet to be successful.
2011-10-04
Technical Paper
2011-36-0210
Maurício Vicente Corrêa, Luiz Gustavo Campos, Luiz Carlos Pereira
The automotive industry is spending a huge amount of money searching for new technologies, focused on cost reduction of product and/or process, quality improvements and nowadays aiming for environmental improvements. This paper shows a new technology applied to the automotive industry and a new development of production process of painting with chromed plate appearance. Chromed plate is a traditional electrolytically deposited chromium coating on the first surface of plastic components used in several automotive parts to improve the vehicle jewel effect, more often to differentiate luxury levels into a vehicle platform (in this case for top level vehicles), but with some dramatically important issues, such as: process scraps, part costs and heavy metals in their composition. This new technology is environmentally friendly chrome appearance (water-based without heavy metals), and has reduced costs, compared with the traditional process of chroming.
2011-10-04
Technical Paper
2011-36-0371
Rafael Navarenho de Souza, Leonardo Navarenho de Souza Fino
It has the aim to discuss the evolution of electronics components, integrated circuits, new transistors concepts and associate its importance in the automotive modules. Today, the challenge is to have devices which consume less power, suitable for high-energy radiation environment, less parasitic capacitances, high speed, easier device isolation, high gain, easier scale-down of threshold voltage, no latch-up and higher integration density. The improvement of those characteristics mentioned and others in the electronic devices enable the automotive industry to have a more robust product and give the possibility to integrate new features in comfort, safety, infotainment and telematics modules. Finally, the intention is to discuss advanced structures, such as the silicon-on-insulator (SOI) and show how it affects the electronics modules applied for the automotive area.
2011-10-04
Technical Paper
2011-36-0098
Sérgio M. Hanriot, Bruno Teixeira Vieira
This research presents a study of a refrigeration cycle performance on an automotive air conditioning system, specially the refrigerant charge on the system efficiency. The set is composed basically of a fixed displaceable rotary vane compressor, expansion valve, condenser and evaporator. The objective of this research is to analyze the air conditioning efficiency in a small car, considering its diverse characteristics and environmental conditions. It was made some experiments by using a vehicle inside a climatic chamber with different configurations and environmental conditions, in order to improve the system efficiency by measuring the impact of each variable that affects the operating condition. The experimental results showed a great potential improvement of the system by changing the refrigerant mass.
2011-06-09
Technical Paper
2011-37-0013
Klaas Burgdorf
Maintaining the current ratio between certified and the customer-observed fuel consumption even with future required levels poses a considerable challenge. Increasing the efficiency of the driveline enables certified fuel consumption down to a feasible level in the order of 80 g CO₂/km using fossil fuels. Mainly affecting off-cycle fuel consumption, energy amounts used to create good interior climate as well as energy-consuming options and features threaten to further increase. Progressing urbanization will lead to decreasing average vehicle speeds and driving distances. Highly efficient powertrains come with decreased amounts of waste energy traditionally used for interior climate conditioning, thus making necessary a change of auxiliary systems.
2011-05-17
Journal Article
2011-01-1687
Sachin Wagh, Prasanth B, David Hudson
In worldwide automotive markets, the migration of customers towards smaller cars having compact, fuel-efficient design is well established and accepted as an engineering challenge by global automotive OEMs. Tata Motors of India has established a precedent by developing an ultra low cost and light weight car (the Nano), and has thereby created a new market segment for such cars that are more affordable to most of the population. This is now becoming established as a brand of low cost, safe transport in both rural and urban market segments. Despite the market moving towards such compact, fuel-efficient designs, customers are unwilling to lose many of the vehicle attributes to which they have been accustomed in previous types of entry-level cars. Addressing this marketing requirement places some significant challenges before the designers of this type of car.
2011-04-12
Technical Paper
2011-01-1318
Eduardo Alano, Emmanuel Jean, Yohann Perrot, Jean-Paul Brunel, Nicolas Ferrand, Mehdi Ferhan, Julien Chapel, Karine Pajot
Stringent emissions standards (Euro 6 and Tier2Bin5) lead to the use of nitrogen oxides (NOx) aftertreatment. One of the most widespread technical solutions able to meet these legislations is Urea Selective Catalytic Reduction (Urea SCR). A urea aqueous solution is introduced into the exhaust system in order to reduce NOx over SCR catalyst. Before reaching the catalyst, the aqueous solution has to be transformed into ammonia. Current serial applications need long distances (≻ 400 mm) from injection point to SCR catalyst and a mixer apparatus to ensure sufficient mixing between exhaust gas and ammonia. Because of this distance, SCR catalyst is located far from the engine. The light-off of the catalyst is penalized and therefore the efficiency of the SCR system is low. The purpose of this paper is to show a compact mixing device able to ensure mixing in a short distance (~ 75 mm).
2011-04-12
Technical Paper
2011-01-1429
Yanxiao Fu, Yang Yang, Xiangyang Xu, Yanfang Liu
With the rapid development of the world's automobile industry, china's car sales have increased with each passing day. The automobile industry has become one of china's leading industries, and the market share of the automatic transmission in the Chinese car market is growing rapidly. Based on the actual status of the automatic transmission industry in china, we analyze the present condition and development tendency of the automatic transmission market in china in this thesis. We analyze and discuss some features like structure, design, technology of the AT / AMT / CVT / DCT and their adaptability in Chinese automatic transmission market. On that basis we bring forward a conceptual design of a 8-speed automatic transmission which is for a front-wheel drive vehicles, then we analyze the feature of 8AT's design, introduces the design and engineering development of 8AT.Finally, we discuss the possibility SOP of 8AT in China.
2011-04-12
Journal Article
2011-01-0175
Wolfgang Mayer, Gerhard Wickern
The paper describes the aerodynamic development and optimization process of the three different new models of the Audi A6/A7 family. The body types of these three models represent the three classic aerodynamic body types squareback, notchback and fastback. A short introduction of the flow structures of these different body types is given and their effect on the vehicle aerodynamic is described. In order to achieve good aerodynamic performance, the integration into the development process of the knowledge about these flow phenomena and the breakdown of the aerodynamic resistance into its components friction- and pressure drag as well as the induced drag is very important. The paper illustrates how this is realized within the aerodynamic development process at Audi. It describes how the results of CFD simulations are combined with wind tunnel measurements and how the information about the different flow phenomena were used to achieve an aerodynamic improvement.
2011-04-12
Journal Article
2011-01-0166
David Sims-Williams, David Marwood, Adam Sprot
The rear end geometry of road vehicles has a significant impact on aerodynamic drag and hence on energy consumption. Notchback (sedan) geometries can produce a particularly complex flow structure which can include substantial flow asymmetry. However, the interrelation between rear end geometry, flow asymmetry and aerodynamic drag has lacked previous published systematic investigation. This work examines notchback flows using a family of 16 parametric idealized models. A range of techniques are employed including surface flow visualization, force measurement, multi-hole probe measurements in the wake, PIV over the backlight and trunk deck and CFD. It is shown that, for the range of notchback geometries investigated here, a simple offset applied to the effective backlight angle can collapse the drag coefficient onto the drag vs backlight angle curve of fastback geometries.
2011-04-12
Technical Paper
2011-01-0164
Johannes Wojciak, Pascal Theissen, Kirstin Heuler, Thomas Indinger, Nikolaus Adams, Rainer Demuth
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.
2011-04-12
Journal Article
2011-01-0291
Daniel Fittanto, Cleve Bare, James Smith, Chimba Mkandawire
Low-speed sideswipe collisions between tractor-semitrailers and passenger vehicles can result in large movements and extensive areas of visible damage to the passenger vehicle. However, depending on the specifics of the collision, the resulting crash pulse may be extended, and the vehicle accelerations correspondingly low. Research regarding the impact environment and resulting injury potential of the occupants during these types of impacts is limited. Five full-scale crash tests utilizing a tractor-semitrailer and a passenger car were conducted to explore vehicle responses during these types of collisions for both the passenger car and the tractor-trailer. The test vehicles included a loaded van semitrailer pulled by a tractor and three identical mid-sized sedans. Instrumentation on the sedans included accelerometers and rotational rate sensors, and the vehicle and occupant kinematics were recorded using onboard and off-board real-time and high-speed video cameras.
2011-01-19
Technical Paper
2011-26-0119
J. S. Karajagikar, N. R. Rajhans, B. B. Ahuja, R. G. Rajhans
In India, small car segment is having maximum sale, which includes cars like Maruti 800, SUZUKI Swift, Maruti Alto, Tata Indica, etc. Driver seat is one of the main aspects to be considered while defining comfort in a moving vehicle. The current analysis concentrates on driver seat because driver comfort is of main concern since it is the most occupied seat in any vehicle and the occupancy is for longer duration. In addition to sitting, the driver's job is to manipulate different controls and concentrate parallely on many aspects. The research work aims at studying the vertical vibrations transferred to the human body via seat. The work is an attempt towards studying dynamic characteristics of driver seat for comfort through objective evaluation. For objective evaluation, two tests were conducted; Seat Effective Amplitude Transmissibility (SEAT) test and Ride Comfort Index test under two different conditions, i.e., car level and seat level testing on Car "A" and Car "B."
2011-01-19
Technical Paper
2011-26-0083
Mukti Prasad, Arghya Sardar, Sajid Mubashir
Transmission systems have significant impact on drive ability and fuel economy of the vehicle. Electronic control and increased gear ratios have played a major role in the evolution of transmission systems in improving gear-shift comfort, drive ability and fuel economy. New transmission technologies being developed include “Automated Manual (AMT) transmissions”, with both single-clutch and Dual Clutch (DCT) or Direct Shift (DSG) variants, and Continuously Variable Transmission (CVT). In India the manual type transmission is prevalent, whereas automatic and automated manual systems are slowly making their presence. It is expected that India will become world's largest producer of small car, which requires transmission systems that are low cost while at the same time offer comfortable smooth shifting, and fuel efficiency. Due to the space constraint in the small car, packaging is a challenge for transmission systems for small cars.
2011-01-19
Technical Paper
2011-26-0055
Dinesh Mana, N. Dhanendra Kumar, B. Somasekhar
Thermoplastic materials, due to their inherent light weightiness and high ductility, are increasingly used in the design of front and rear beams of automobiles. These beams are found to be effective in reducing damages to engine and other costly components of an automobile during its low-speed collision with another automobile. While these beams are also advantageous in many other aspects that include performance and reduced assembly, cost is one of the limiting factors for the large-scale absorption of thermoplastic beams in automobiles. Therefore, in the current global economy, each automobile Original Equipment Manufacturer (OEM) is seeking an energy management solution that meets performance with minimum weight targets. Topology optimization is capable of generating non-intuitive and optimum designs with minimum materials present.
2011-01-19
Technical Paper
2011-26-0107
Ashish Singh, Santhosh Kumar, Kishor Nikam
In this paper, benefits of high performance CFD computations for ground vehicle aerodynamics are discussed with the examples of Ahmed body and Formula SAE external aerodynamics. Both problems are highly compute intensive in terms of physics and their grid resolutions. Grid resolution is usually kept high to resolve flow separation, wake kind of complex physical phenomenon. For this, computations have been performed for more than 20 million cells grid. Firstly, Reynolds Averaged Navier-Stokes (RANS)-based turbulence study of Ahmed model is done for three slant angle variations, 25°, 30°, and 35°. Sensitivity of solver on solution is analyzed by a grid refinement study. The 2 million and 22 million cells mesh are used for the detailing of solution accuracies and solver speed up. Commercial solver, CFD++, and open source solver, OpenFOAM, are used for RANS computations. Their speed up test is done on supercomputer Eka.
2011-01-19
Technical Paper
2011-26-0017
Karthik Chittepu
In the automotive industry, crash analysis plays an important role in the virtual product development of the design of the car body. The minimization of weight and competing requirements from several load cases have to be adjusted as optimal as possible. Consequently, high safety limits cannot be kept while maintaining all requirements. Therefore, the assurance of robustness of the optimized design against unavoidable scatters of crash test constraints, production constraints and material constraints in preferably early stages of product development becomes more and more important. Therefore, numerical robustness analysis is recommended as method of stochastic analysis in virtual product development. Robustness analysis is primarily carried out to determine the variation range of significant response variables and their evaluation by using definitions of system robustness due to the unavoidable scatter of design parameters.
2011-01-19
Technical Paper
2011-26-0040
S. Pathak, Y. R. Singh, S. K. Singal, A. K. Jain, L. Robindro
In India, continuous efforts are being made to upgrade fuel quality and vehicle technology for meeting European emission norms. However, these efforts make a very little impact in improving the air quality due to exponential increase in the vehicle population and the poor quality of the Indian roads. The long-term strategy for meeting the requirement of huge road infrastructure and traffic management systems needs immediate attention. Studies have been conducted worldwide to study the effect of fuel quality and vehicle technology on fuel economy and emissions. However, the contribution of road quality, traffic management and driver training on reduction of vehicular emissions and improvement of fuel economy under Indian road conditions is still not established.
2010-10-17
Technical Paper
2010-36-0545
Fred Mendonça, Alex Read, Fabiano Imada, Vinicius Girardi
The transport industries face a continuing demand from customers and regulators to improve the acoustic performance of their products: reduce noise heard by passengers and passersby; avoid exciting structural modes. In both the aerospace and automotive areas, flow-induced noise makes a significant contribution, leading to the desire to understand and optimize it through the use of simulation. Historically, the need for time-consuming, computationally expensive transient simulations has limited the application of CFD in the field of acoustics. In this paper are described efficient simulation processes that, in some instances, remove the requirement for transient analyses, or significantly reduce the total process time through intelligent pre-processing. We will outline this process and provide both automotive and aerospace industrial examples, including analyses of highly complex geometries found in real life.
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