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Viewing 1 to 30 of 3573
2004-03-08
Technical Paper
2004-01-0412
F. Bozza, A. Gimelli, V. Pianese, S. De Martino, R. Curion
The paper details recent results concerning the design of a new intake system for a 1.4 liter displacement ELASIS-FIAT engine. A classical approach, based on theoretical one-dimensional characterization of the whole system, is presented. This approach, however, requires a relevant number of geometrical information which are usually unavailable in the first phase of the design process. For this reason, a statistical analysis on a number of existing devices was also carried out to the aim of providing such initial data as a function of prescribed levels of pressure losses and noise emission for the device. The methodology allows then to define a base configuration of the system, to start the 1D analyses. The base geometry is further refined taking into account the layout constraints and the presence of resonators for the reduction of the noise emission. Experimental data collected on a prototype of the designed system have confirmed the robustness of the whole design procedure.
2004-03-08
Technical Paper
2004-01-0400
C. Grasso, M. Martorelli, L. Petrella, F. Sbarbati
Over the last decade, demands regarding noise and vibration performance of whole vehicle and, in particular, powertrain are steadily increasing as a consequence of continuous product growth. This paper describes the NVH refinement for a new powertrain. The main phenomena, we focused on throughout this work, are booming noise and “engine presence”. Several solutions have been tested, in order to resolve one or both of these acoustical problems, and each of them is presented from the rough evaluation stage to the final tuning phase. The work mainly focused on the powertrain “structure”, i.e. to increase its stiffness, and on the crankshaft plus flywheel system.
2004-03-08
Technical Paper
2004-01-0387
Deming Wan, Dirk Tomas Soedel
The Helmholtz resonator is widely used in vehicle exhaust system tuning. The classic Helmholtz theory is based on the Newton's second law. This approach gives a single resonance frequency and a corresponding attenuation peak. This paper reviews the approach of the one degree of freedom (DOF) Helmholtz system, and extends it to a two-DOF system. The two-DOF system is composed of two Helmholtz resonators which are in series. The new system is described by a two DOF lump-mass vibration system. The theoretical derivation of the two-DOF system is presented in this paper. The two-DOF system has two resonance frequencies as expected. The case studies of the two-DOF system are also provided. The developed system has been correlated to computational results (GT-Power©) and experimental results (transmission loss test). The correlation shows that the presented approach for the two-DOF system can correctly predict the resonance frequency of the Helmoltz resonators in general.
2004-03-08
Technical Paper
2004-01-0403
Hoi Sum IU, W. L. Cleghorn, J. K. Mills
Fuel slosh inside an automotive fuel tank was found to generate unpleasant noise. This paper presents the analysis of several baffle designs to suppress the fuel slosh by using a commercial Computational Fluid Dynamics software, FLOW-3D®, and performing slosh experiments. Estimated mean kinetic energy and average turbulent kinetic energy of the fluid obtained from the computer simulations were used to compare with sound measurements obtained from the slosh experiments. The slosh experiments were recorded using high speed video equipment enhanced with a data acquisition system to take sound measurements. The simulation results showed that approximately 70% energy reduction from the No-baffle configuration could be achieved with the best baffle configuration. The experimental results demonstrated that at low fluid level, the performance of different baffle configurations was approximately the same.
2004-03-08
Technical Paper
2004-01-1547
Ramesh Edara, Shan Shih
Multibody Dynamics Simulation (MDS) studies are valuable in providing guidance in suspension systems design and reduce product development cost and time. These studies are used in various stages of suspension system design and development. In both concept study and detailed design the subsystem kinematics, dynamics and full vehicle dynamics studies are used. In this paper, four case studies for suspension system performance optimization using MDS studies are presented.
2004-03-08
Technical Paper
2004-01-1541
Daniel G. Dickson
Much has been written over the years regarding the advantages of using microcellular polyurethane (MPU) within the area of chassis and suspension systems. However, there have been limited discussions in an open forum of the geometric design requirements for MPU jounce bumpers. The objective of this paper is to provide a primer for MPU jounce bumper design for engineers working in the chassis and suspension field. Geometric design principles and the effects on manufacturability and durability will be presented to systematically show the limitations and advantages of MPU technology in creating a final jounce bumper design.
2004-03-08
Technical Paper
2004-01-1569
Jürgen Engbring, Matthias Ebert, Stefan Werry
For several years flat cables for the use in the automotive wiring harnesses have been attracting attention. Less weight, less space and higher automation degree are the key factors, which promise a benefit from the introduction of the new technology. The well defined electromagnetic properties are also often mentioned as an advantage of flat cables, because of the precise and constant routing in the car. Although it is true, that statistical error due to an unfavorable position of the cables in the harness is reduced, on the other hand the systematical error due to it's geometry is strongly enhanced. Since basic parameters like impedance or crosstalk characteristics are not specified for the cable types for CAN-transmission used in automotive, it is difficult to qualify a selected wiring system in the early development phase of a car model.
2004-03-08
Technical Paper
2004-01-1460
Lars Eriksson
A program package, that calculates chemical equilibrium and thermodynamic properties of reactants and products of a combustion reaction between fuel and air, has been developed and validated. The package consists of the following four parts: 1) A program for calculating chemical equilibrium. 2) A database that contains thermochemical information about the molecules, which comes from the GRI-Mech tables. 3) A GUI that allows the user to easily select fuels, fuel/air ratio for the reaction, and combustion products. 4) A set of functions designed to access the thermochemical database and the chemical equilibrium programs. Results are validated against both the NASA equilibrium program (Gordon and McBride, 1994) and the program developed by Olikara and Borman (1975). It is shown that the new method gives results identical to those well recognized Fortran programs.
2004-03-08
Technical Paper
2004-01-1492
Katherine W. Hughes
This paper seeks to accomplish two objectives. The first is to understand the emissions performance of the newest experimental substrates. The second is to verify or refute the hypothesis that a higher cell density part will age more severely in the same conditions than the lower cell density part. This paper will also seek to identify when during aging this occurs and the shape of the curve of performance loss for each cell density. Three configurations including thinwall and ultra-thinwall cell geometries were tested. The test consisted of five repeated iterations in partial aging and testing, up to 100 hours of aging. The steps were in uneven increments to gain the most knowledge about the aging curve. Testing was performed after each partial aging step on a chassis dynamometer ULEV vehicle using the 3 bag FTP protocol.
2004-03-08
Technical Paper
2004-01-1489
Bruce Campbell, Alex Finch, Paul Tancell, Andrew Hitchings, Mark Marsh, David Lloyd-Thomas, David Gregory
The emissions performance of a prototype close-coupled catalyst system has been analysed and compared with semi-close-coupled and underfloor systems. Under certain engine conditions during the stabilized region of the ECE Stage 3 drive-cycle, the close-coupled system has showed higher emissions than the semi-close-coupled or underfloor configurations. Using fast response emissions analysers and catalyst warm-up characteristics in conjunction with Computational Fluid Dynamics (CFD), the reasons for this emissions performance deficit has been attributed to flow maldistribution across the front face of the catalyst.
2004-03-08
Technical Paper
2004-01-1361
Kenichi Mitsuhashi, Takashi Tsuchiya, Shin Morishita, Toshihiko Shiraishi, Hiroshi Sasaki
The performance of various types of control systems for an electric governor of a diesel engine was examined. The amount of fuel injection of a diesel engine is usually controlled by an electric governor system in these decades, and a PID controller is installed for the electric governor. Even when the optimal parameters for PID controller are well tuned, it is difficult to keep constant rotation speed of the engine, because the applied load to generators may vary according to its running conditions. In this study, a neural network was applied to regulate the parameters in the PID controller for the axial-moving DC motor to control the amount of fuel injection. Experimental studies show that the parameter regulation system using neural network presented here showed good performance under various running conditions. Furthermore, it was shown that various types of training algorithms were applied to neural network control systems and their performance was compared.
2004-03-08
Technical Paper
2004-01-1363
Helge Nareid, Neil Lightowler
New environmental legislation places increasing demands on automobile emission controls, requiring new approaches to engine management and diagnostics systems. This paper demonstrates the use of an Artificial Neural Network (ANN) solution for misfire detection in spark ignition engines. The solution is based on a truly parallel hardware implementation of an ANN. The network is developed by a data-driven training process, using data with known incidences of misfires. No analytical or algorithmic methods need to be developed in order to train or use the ANN for misfire detection. There is minimal processing overhead on the main processor of the engine management unit, freeing resources for alternative engine management tasks or enabling the use of less costly processor solutions.
2004-03-08
Technical Paper
2004-01-1289
A. P. Walker, P. G. Blakeman, T. Ilkenhans, B. Magnusson, A. C. McDonald, P. Kleijwegt, F. Stunnenberg, M. Sanchez
Selective Catalytic Reduction (SCR) systems will be widely used to meet the Heavy Duty Diesel (HDD) Euro IV emissions legislation. Reports on a number of demonstrations of such systems have already been published, but the long-term durability of such systems is still to be proven. The potential catalyst deactivation induced by oil-derived species and thermal processes have, up to now, received very little attention, despite the fact that these HDD emission control systems will need to be durable for distances of the order of 500,000 km or more. This paper describes the development and performance of a new family of SCR catalyst with very high thermal durability and poison resistance. The thermal durability of the catalyst was initially demonstrated within long-term, high temperature engine bench ageing studies.
2004-03-08
Technical Paper
2004-01-1276
S. Eckhoff, W. Mueller, D. Lindner, J. Leyrer, T. Kreuzer, G. Vent, C. Schoen, J. Schmidt, J. Franz
To meet future emission levels the industry is trying to reduce tailpipe emissions by both, engine measures and the development of novel aftertreatment concepts. The present study focuses on a joint development of aftertreatment concepts for gasoline engines that are optimized in terms of the exhaust system design, the catalyst technology and the system costs. The best performing system contains a close-coupled catalyst double brick arrangement using a new high thermal stable catalyst technology with low precious metal loading. This system also shows an increased tolerance against catalyst poisoning by engine oil.
2004-03-08
Technical Paper
2004-01-1070
Yoshiyuki Yasui, Wataru Tanaka, Yuji Muragishi, Eiichi Ono, Minekazu Momiyama, Hiroaki Katoh, Hiroaki Aizawa, Yuzo Imoto
It is well known that the self-aligning torque decreases before lateral force is saturated. Focusing on this self-aligning torque change, an estimation method has been developed to detect the friction condition between steered wheels and road surface before the lateral force reaches the friction limit. The lateral grip margin (LGM) is defined based on the self-aligning torque change, which is obtained using the EPS torque and motor current information. The LGM is theoretically analyzed based on the tire model and experimentally verified through the full-scale vehicle test. Moreover, the estimated LGM is applied for the chassis control systems to improve the vehicle dynamics performance.
2004-03-08
Technical Paper
2004-01-0608
Klaus Gebauer, Adrian Gavrilescu
Engine efficiency and environmental issues have increased the need for high performance engine parts. Of significant importance is the moving mass of the valve train components. Lower masses reduce inertia and this reduces friction losses. New technology inquiries from customers, market competition, possible weight reductions of 20-50%, and the ability to withstand increased operating temperatures by 100-150°C, have increased the need to develop high performance automotive engine valves at competitive costs. Lightweight hollow valves could be mentioned as one of the major targets for the development work. Achieved goals can directly be translated into lower engine working temperature or higher compression ratios for conventional engines. Also, there is a close cooperation between TRW's development and design teams of the lightweight valve project and the electromagnetic valve actuation programs (EMVA).
2004-03-08
Technical Paper
2004-01-0610
Gao Wenzhi, Feng Jingqi, He Zhaoxin
The valve train is an important system in automotive engine. It can assure valves open and close at the right time by controlling cam profile. The adequate duration of valve opening, suitable velocity and acceleration of valve closing can be assured by the cam profile. The design of the valve train directly influences engine performance, exhaust emission, reliability, vibration and noise. In particular, the high-speed automotive engine requires valve train not only operating smoothly, reliably but also having a good performance. So it increases the challenge of valve train design. Typically, the designers choose the symmetrical cam profile. The symmetrical valve cam is suitable to low and medium speed engines, but with the rising of engine speed, valve closing velocity and acceleration increase, vibration and noise coming from valve loading become intense, so abrasion of valve will be accelerated and durability of the valve train will be deteriorated.
2004-03-08
Technical Paper
2004-01-0600
Vinicius José M. Peixoto, Walter Zottin
Some of the current engine design requirements are the reduction of the engine weight and size and the power increasing. The components, like the connecting rod, should be re-designed in order to attend the trends. Other important variables are the increase of the engine speed and the peak cylinder pressure, higher the engine speed and peak cylinder pressure, higher the inertia and the gas pressure loads, respectively [2]. The combination of the trends mentioned before directly affects the con-rod bearing performance. In most cases, the optimization of the bearing profile can generate a significant improvement on the bearing performance. The use of the EHL numerical simulation is a powerful tool to design bearings and evaluate their performance. This paper presents, based on the EHL theory, a numerical evaluation of the performance of different connecting rod bearing profiles, both in circumferential and axial bearing directions.
2004-03-08
Technical Paper
2004-01-0649
Juergen Greiner, Christoph Doerr, Harald Nauerz, Michael Graeve
In September 2003, the Mercedes Car Group set another milestone by introducing the fifth generation of automatic transmissions developed and manufactured in-house since 1960. The world's first 7-speed automatic transmission 7G-TRONIC is featured in the Mercedes-Benz S, SL, CL and E-Classes with V8 gasoline engines. Deduced from the demands of the requirement specifications, the 5-speed automatic transmission was decisively improved; the result is a clear increase in spontaneity, agility, fuel economy, and driving comfort for the customer. And because of the harmony between the vehicle and its powertrain, excellent results in the areas of performance, reduced emissions, comfort, and acoustics are obtained.
2004-03-08
Technical Paper
2004-01-0622
Viatcheslav Naoumov, Aleksey Demin, Andrey Sokolov
During last four years the authors were involved in the simulation and investigation of combustion and ionization in the cylinder of gasoline and natural gas Spark Ignition (SI) engine. Two-zone model of combustion and chemical non-equilibrium ionization and results of the numerous numerical investigation were presented by the authors at SAE 2002 and SAE 2003 World Congresses. This model and numerical results provided an important insight into combustion products behavior and gave the chance to find correlation between chemical and thermal ionization of combustion products and SI engine performances. In order to provide better correspondence of the numerical data to the experimental results in the wide range of operational parameters for different geometry of engines a new three-zone model was developed and successfully tested.
2004-03-08
Technical Paper
2004-01-0730
Takashi Inoh, Yuji Kageyama
We studied the use of Bio-plastics (plastics made from plants) such as poly(lactic acid) (PLA) to automotive parts. To apply this material to automotive plastic parts, improvement in heat and impact performance is required. From the viewpoint of suppressing the increase in CO2 emissions, we attempted to improve the performance of PLA by combining with natural fiber. As the result, we could improve both heat and impact performance. In addition, we could achieve higher modulus and lower bulk density, which leads to the weight reduction of automotive parts.
2004-03-08
Technical Paper
2004-01-0733
Val A. Kagan, Russell J. Nichols
The advantages of magnetic implant induction welding (Emabond™)1 technology for various thermoplastics were widely discussed since the mid-eighties in a series of technical articles and reports, and presented to the professional Societies (SAE, SPE, SME, etc). In 1998-2003, we reported to SAE International our technical achievements in optimizing the mechanical performance of welded nylon (6, 66, 6/66, 46, etc.) using frictional (linear and orbital vibration, ultrasonic), contact (hot plate), and non-contact (laser through-transmission) welding technologies. Our recent developments focused on optimization of mechanical performance of induction welded nylon 6, which has reached a new performance level through continuous improvement of magnetic implant induction welding technology, including properties of the formulated magnetic implant material, new equipment, SPC process control, optimized design of joints, etc.
2004-03-08
Technical Paper
2004-01-0763
Taeyoung Chung, Kyongsu Yi, Jeongtae Kim, Jangmoo Lee
This paper presents a closed-loop evaluation of the Vehicle Stability Control (VSC) systems using a vehicle simulator. Human driver-VSC interactions have been investigated under realistic operating conditions in the laboratory. Braking control inputs for vehicle stability enhancement have been directly derived from the sliding control law based on vehicle planar motion equations with differential braking. A driving simulator which consists of a three-dimensional vehicle dynamic model, interface between human driver and vehicle simulator, three-dimensional animation program and a visual display has been validated using actual vehicle driving test data. Real-time human-in-the loop simulation results in realistic driving situations have shown that the proposed controller reduces driving effort and enhances vehicle stability.
2004-03-08
Technical Paper
2004-01-0773
Pinhas Barak, David-Peter Herczeg, Caleb Hollier, Patrick Recker, Travis Slagle, Travis Slagle
Standard analysis of vehicle dynamics often treats the steering system as a rigid system. This paper examines the response of a compliant steering system via a mathematical model and computer simulation using MATLAB. This model represents a valuable tool for examination of steering system component stiffness effects on vehicle response. The vehicle chosen for analysis is a typical passenger sedan. The input represents a situation experienced during standard vehicle operation as well as emergency avoidance maneuvers. The findings of this paper will benefit those engineers interested in the steering performance of typical passenger vehicles. Any problems in vehicle performance relating to the steering system, such as steering precision, response, and gain, to name a few, can be made apparent through equation derivation and simulation such as was done in this paper.
2004-03-08
Technical Paper
2004-01-0778
Ye Xiaoming, Chen Guohua, Jiang Yankun, Zou Yunchuan
A three-dimensional EHL analysis has been presented to investigate tribological performance of piston ring and cylinder liner contact. The average Reynolds equation and asperity contact approach are applied. For a more realistic simulation, the factors that have effects on the tribological performance of piston ring are considered as many as possible. The equation has been solved cyclically in a fully flooded inlet boundary condition and a flow-continuity Reynolds boundary condition for cavitation outlet zone. The results show that the elastic deformation and cylinder liner shape significantly affect the tribological performance of piston ring. A heat transfer model has been built to evaluate the effect of friction heat on the temperatures of piston ring pack and cylinder liner. The temperature fields can be acquired by the FEM. The results show that the friction heat mainly affects the temperature of region near the top ring groove.
2004-03-08
Technical Paper
2004-01-0893
Gregory L. Ohl, Michael J. Prucka, Fadi S. Kanafani, Mark J. Duty, Eugene DiValentin, Denise M. Kramer
The simultaneous demand for improvements to performance, drivability, emissions, and fuel economy are driving increasingly complex automotive powertrain solutions. New controls strategies are required to effectively manage and fully utilize the opportunities presented by these new powertrains. This paper outlines the advance powertrain controls development work underway within DaimlerChrysler Corporation, in support of these requirements. A powertrain coordination strategy that translates the driver demand into the most effective combination of all powertrain elements is described. A common interface to the powertrain elements is proposed.
2004-03-08
Technical Paper
2004-01-0861
Jerry Kinsey
Limited slip differentials offer significant performance benefits over standard differentials. Depending on the style and design, mobility and/or handling can be improved. Oftentimes, one must be improved at the expense of the other. For a speed sensitive limited slip differential, mobility can be improved by aggressive tuning. This would normally give adverse handling effects, due to the aggressiveness. If the differential is tuned for handling characteristics, mobility will be compromised, due to the moderate tuning. To optimize the performance, tuning must be adjustable according to the vehicle's input parameters. This paper will show the benefits of adjustable tuning in handling, mobility, and compatibility with other vehicle systems, such as ABS, Traction Control, and Stability Control.
2004-03-08
Technical Paper
2004-01-0985
Masahito Shiraki, Yoshiyuki Moroi, Tsutomu Tanaka, Hidetoshi Tokuno, Hitoshi Nakamura
This paper describes a new 5.6-liter DOHC V8 engine, VK56DE, which was developed for use on a new full-size sport utility vehicle and a full-size pickup truck. To meet the demands for acceleration performance when merging into freeway traffic, passing or re-acceleration performance from low speed in city driving and hill-climbing or passing performance when towing, the VK56DE engine produces high output power at top speed and also generates ample torque at low and middle engine speeds (90% of its maximum torque is available at speeds as low as 2500 rpm). Furthermore, this engine achieves top-level driving comfort in its class as a result of being derived from the VK45DE engine that was developed for use on a sporty luxury sedan. Development efforts were focused on how to balance the required performance with the need for quietness and smoothness.
2004-03-08
Technical Paper
2004-01-0937
H. Kopecek, E. Wintner, M. Lackner, F. Winter, A. Hultqvist
A laser-induced spark was generated inside the combustion chamber of a reciprocating engine running in Homogeneous Charge Compression Ignition (HCCI) mode to investigate the influence of the plasma on combustion performance. For a fuel consisting of 90% natural gas and 10% isooctane, the advance of combustion due to the plasma was found to be strong up to air excess ratios of λ = 2.3 and to cease completely above λ = 2.7. Combustion timing was advanced with increasing advance of plasma timing to a certain extent. The laser was able to sustain HCCI combustion even at much lower inlet temperatures than normally required without plasma. Inlet temperature changes of more than 10 °C could not eliminate laser stimulated HCCI combustion. A potential application of laser stimulated ignition is as a means to actively control HCCI combustion timing.
2004-10-25
Technical Paper
2004-01-3058
Stanislav V. Bohac, Dennis N. Assanis
Despite remarkable progress made over the past 30 years, automobiles continue to be a major source of hydrocarbon emissions. The objective of this study is to evaluate whether variable exhaust valve opening (EVO) and exhaust valve closing (EVC) can be used to reduce hydrocarbon emissions. An automotive gasoline engine was tested with different EVO and EVC timings under steady-state and start-up conditions. The first strategy that was evaluated uses early EVO with standard EVC. Although exhaust gas temperature is increased and catalyst light-off time is reduced, the rapid drop in cylinder temperature increases cylinder-out hydrocarbons to such a degree that a net increase in hydrocarbon emissions results. The second strategy that was evaluated uses early EVO with early EVC. Early EVO reduces catalyst light-off time by increasing exhaust gas temperature and early EVC keeps the hydrocarbon-rich exhaust gas from the piston crevice from leaving the cylinder.
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