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Viewing 1 to 30 of 2632
2011-04-12
Technical Paper
2011-01-0447
Arkadeb Ghosal, Paolo Giusto, Prakash Peranandam, Purnendu Sinha, Haibo Zeng
Recent trends in the automotive industry show growing demands for the introduction of new in-vehicle features (e.g., smart-phone integration, adaptive cruise control, etc.) at increasing rates and with reduced time-to-market. New technological developments (e.g., in-vehicle Ethernet, multi-core technologies, AUTOSAR standardized software architectures, smart video and radar sensors, etc.) provide opportunities as well as challenges to automotive designers for introducing and implementing new features at lower costs, and with increased safety and security. As a result, the design of Electrical/Electronic (E/E) architectures is becoming increasingly challenging as several hardware resources are needed. In our earlier work, we have provided top-level definitions for three relevant metrics that can be used to evaluate E/E architecture alternatives in the early stages of the design process: flexibility, scalability and expandability.
2011-04-12
Technical Paper
2011-01-0411
H Pandarinath, J Sureshkumar, Ramalingam Sivanantham, S Prabhakar, S R Nagendiran
Vacuum pumps are predominantly used in diesel engines of passenger cars and trucks for generating vacuum in servo brake applications. With the emission norms getting stringent, there is a need for vacuum signal for EGR actuation, turbo-charger waste gate actuation and other servo applications. These multi-functional applications of vacuum pumps and the functional criticality in application like braking system demand an effective and reliable performance. In gasoline engines, the vacuum generated in the intake manifold is tapped for braking. The recent technology of gasoline direct injection compels the use of vacuum pump in gasoline engines also due to scarce vacuum in intake manifold. The performance of the vacuum pump is highly dependent on the opening and closing of the check valve sub-system, which is positioned between the vacuum reservoir and the pump at the suction side.
2011-04-12
Journal Article
2011-01-0228
Anthony George Konstantino, Mark A. Levine
This paper summarizes the Fast Fourier Transform (FFT) methodology, special equipment, set-up and testing that is recommended to properly characterize the surface of bearing journals that will not result in objectionable noise or vibration. Traditional surface profiles and finish callouts do not capture some of the key characteristics for addressing what is often the customer's greatest complaint, noise. Noise can vary based on the sensitivity of the vehicle but understanding how to accurately describe (design, test, and measure) a surface for a given vehicle can result in an optimized design and reduce process time during manufacturing. Furthermore, this paper will recommend techniques for determining the proper limits of the FFT callouts.
2011-04-12
Technical Paper
2011-01-0695
Hossein Javaherian, Alan W. Brown, Michael P. Nolan
A frequency-domain approach to balancing of air-fuel ratio (A/F) in a multi-cylinder engine is described. The technique utilizes information from a single Wide-Range Air-Fuel ratio (WRAF) or a single switching (production) O₂ sensor installed in the exhaust manifold of an internal combustion engine to eliminate the imbalances. At the core of the proposed approach is the development of a simple novel method for the characterization of A/F imbalances among the cylinders. The proposed approach provides a direct objective metric for the characterization of the degree of A/F imbalances for diagnostic purposes as well as a methodology for the control of A/F imbalances among various cylinders. The fundamental computational requirement is based on the calculation of a Discrete Fourier Transform (DFT) of the A/F signal as measured by a WRAF or a switching O₂ sensor.
2004-03-08
Technical Paper
2004-01-0112
E. Mattarelli, M. Borghi, D. Balestrazzi, S. Fontanesi
Standard design practice usually adopts steady flow tests for addressing optimisation of the intake valve-port assembly. Recently, with more user-friendly CFD tools and with increased computing power, intake stroke simulations, handling both piston and valves motion, have become practical. The purpose of this paper is to compare the design guidelines provided by the standard steady flow tests (both experimental and numerical) and the information coming from a CFD-3D intake stroke analysis. Reference is made to a four valve HSDI Diesel engine. Three swirl control strategies are investigated. It is supposed that one intake valve is kept closed, while the other one operates normally (first strategy). The second strategy consists in a 50% reduction of the lift of both valves. Finally, the third possibility is the blockage of one intake port by means of a simple butterfly valve.
2004-03-08
Technical Paper
2004-01-0126
Hoojoong Kim, Namil Heo, Yongmo Kim, Je-Hyung Lee, Joon Kyu Lee
The Representative Interactive Flamelet(RIF) concept has been applied to numerically simulate the combustion processes and pollutant formation in the direct injection diesel engine. Due to the ability for interactively describing the transient behaviors of local flame structures with CFD solver, the RIF concept has the capabilities to predict the auto-ignition and subsequent flame propagation in the diesel engine combustion chamber as well as to effectively account for the detailed mechanisms of soot and NOx formation. In order to account for the spatial inhomogeneity of the scalar dissipation rate, the Eulerian Particle Flamelet Model using the multiple flamelets has been employed. Special emphasis is given to the turbulent combustion model which properly accounts for vaporization effects on turbulence-chemistry interaction.
2004-03-08
Technical Paper
2004-01-0571
Miguel M. Gomez, Victor H. Mucino, Nigel Clark, James E. Smith
Continuously variable transmissions (CVTs) are usually used in small vehicles due to power limitations on the variable elements. Continuously variable power-split transmissions (CVPST) were developed in order to reduce the fraction of power passing through the variable elements [1,2]. The configuration presented in this paper includes a planetary gear train (PGT), which in combination with the CVT allows the power to be split and therefore increase the power envelope of the system. The PGT also provides a branch that can be used in a hybrid electric vehicle (HEV) operation through an electric motor. A conceptual design of a CVPST for a HEV is presented in this paper. The objectives are to show the different operational modes, with diagrams, perform a power analysis, develop the velocity and force equations and finally show the performance of the system with an example application.
2004-03-08
Technical Paper
2004-01-0562
N.P. Komninos, D.T. Hountalas, D.A. Kouremenos
Homogeneous Charge Compression Ignition (HCCI) engines have the potential of reducing NOx emissions as compared to conventional Diesel or SI engines. Soot emissions are also very low due to the premixed nature of combustion. However, the unburned hydrocarbon emissions are relatively high and the same holds for CO emissions. The formation of these pollutants, for a given fuel, is strongly affected by the temperature distribution as well as by the charge motion within the engine cylinder. The foregoing physical mechanisms determine the local ignition timing and burning rate of the charge affecting engine efficiency, performance and stability. Obviously the success of any model describing HCCI combustion depends on its ability to describe adequately both the chemistry of combustion and the physical phenomena, i.e. heat and mass transfer within the cylinder charge. In the present study a multi-zone model is developed to describe the heat and mass transfer mechanism within the cylinder.
2004-03-08
Technical Paper
2004-01-0365
S. P. Gladyshev, Terry Feldpausch, N. Natarajan, I. S. Okrainskaya
The electrical power consumption in automobiles continues to increase thereby demanding higher power capability of the alternator. The standard alternator today is a claw-pole synchronous machine. The claw-pole alternators have brushes which are maintenance issue; it is not possible to increase power output by increasing the stack length; and the rotor inertia is large due to the steel core and rotor excitation coil. Despite these disadvantages, the claw-pole alternator is still used because of its low cost and ease of manufacturing. An alternator with DC stator excitation, has a laminated salient pole rotor with no excitation coil. Therefore the weight and inertia is less than in the claw-pole alternator. The excitation coil is located in the stator and therefore there are no brushes needed. In this type of alternator, the stator has three-phase output coils evenly shifted in space 120 degrees.
2004-03-08
Technical Paper
2004-01-0382
Naveen Rastogi, Fatma Kocer, Rodolfo Palma
The work presented here outlines the development of a robust CAO tool for optimal design of electromagnetic retarder machines. The developed EM-CAO tool is then used to perform a wide variety of CAE/CAO tasks, from automatically computing the torque versus rpm performance curves of the EM retarder to performing optimization. Two specific examples of optimal design of the EM retarder are reported. Through the use of a task manager/optimizer repetitive jobs are fully automated thereby making the analysis and optimization of electromagnetic retarders faster and user-friendlier.
2004-03-08
Technical Paper
2004-01-0371
Kazuhito Kato, Satoshi Kitazaki, Hideo Tobata
A seat vibration prediction technique using a substructure synthesis method was developed for use in ride comfort evaluations. The human body was modeled as a vibration transfer matrix using the mean apparent mass of human subjects, based on data measured in advance. Seat vibration characteristics were measured with rigid masses on the seat. The measured data and vibration transfer matrix of the human body were synthesized using a substructure synthesis method, to predict vibration of the seat cushion and backrest in an occupant-loaded condition without actually using human subjects. Results showed that seat vibration predicted with this method was very similar to, and more repeatable than, that obtained experimentally with human subjects.
2004-03-08
Technical Paper
2004-01-0428
Wang Gui-hua, Liu Na, Yao Zhang-tao, Huang Xue-zheng
A calculation model for high-speed electromagnet property of electronic-controlled fuel injection system of diesel engine has been formulated with considering of leakage of magnetic flux and resistance of core. The results have been proved by relational tests. The results of an M490F type high-speed electromagnet show that in order to acquire good controlling effect, the resistance of core should not be ignored except it is much bigger than the solenoid resistance.
2004-03-08
Technical Paper
2004-01-0424
Tong Yi, Li Jianqiu, Zhang Junzhi, Yang Fuyuan, Zhang Kexun, Yang Minggao
The internal combustion engine and motor should be controlled coordinately to meet the demand of smooth power transfer and good drivability especially during transient conditions for parallel hybrid powertrain system. This paper presents the essential technology of how to estimate the engine torque by the measurement and processing of instantaneous crankshaft speed. One multi-injection gasoline engine and one turbocharged diesel engine are selected to manifest the algorithm of engine torque estimation and the experiments show fairly good results for both engines. Consequently an engine torque sensor can be easily calibrated and applied to feedback engine torque in coordinating control.
2004-03-08
Technical Paper
2004-01-1553
Shinichi Nishizawa, Jason Logsdon, Maiko Ikeda, Tom Sugiyama, Isao Otani, Naoshi Sato, Akihiko Kumagai, Joseph Harralson, Paul Hozian, Toshio Hamano
Today's suspension coil spring design requires not only accounting for one-dimensional force along the coil spring axis, but also exerting a complex multi-dimensional force and torque field between the spring seats [1,2,3,4,5]. This paper describes the design of a 6-DOF parallel mechanism to mimic the force and torque characteristics of a coil spring. This mechanism can physically generate the 6-DOF force and torque field of a coil spring, allowing designers to experimentally evaluate the quasi-static force effects of a coil spring while still at the design stage. Examples are presented for a physically generated force and torque field of a coil spring used in a McPherson Strut suspension, and its effect is correlated to the side force acting upon the suspension strut. As an extension, this mechanism can be widely used to investigate the relationship between spring characteristics and damper friction.
2004-03-08
Technical Paper
2004-01-1458
Ylva Nilsson, Lars Eriksson
It is important to determine the phasing of a measured cylinder pressure trace and crank angle with high accuracy. The reason is that erroneous determination of the position of TDC is a major error source when calculating properties such as heat release etc. A common way to determine the TDC position is to study motored cycles. Heat transfer makes the task more complicated, since it shifts the position of the maximum pressure away from TDC. In this paper a new method for determining the TDC position is proposed that does not require any additional sensors other than a cylinder pressure sensor and an incremental encoder. The idea is to find a point that the cylinder pressure from a motored cycle is symmetric around, since the volume is close to symmetric on either side of TDC. The new method and four published methods are tested and evaluated. Cylinder pressure data used for comparison are from simulations of a SAAB Variable Compression engine.
2004-03-08
Technical Paper
2004-01-1459
Wang Xiaoyu, Chen Guohua, Jiang Yankun
Non-replicated factorial experiment is a kind of specific experiment, which can analyze factorial experiment with no replicates. This property makes it a useful analytical tool to cooperate with engine simulation for the analysis of engine performance. In the article we use this technique to explore the effects of valve timing variable on engine performance in an SI engine simulation. Results drawn from the analysis can help to give us a better understanding of the mechanism of valve timing.
2004-03-08
Technical Paper
2004-01-1462
Jiří Vávra, Michal Takáts
New regression approach for heat release pattern prediction for various operating conditions for gas fuelled SI engines has been developed and verified. This procedure has been implemented in our engine working cycle simulation code. Crankshaft angle positions of combustion start-point, maximum rate-of-heat-release point and combustion end-point are expressed by the use of regression method as the function of engine operating point specification. Base heat-release pattern is employed in the model in a tabular form. The pattern at a new operating point is derived by stretching the pattern along the crank angle coordinate, fitting it in the most relevant points of the heat release pattern. The regression model is based on the results of experiments of both homogeneous stoichiometric and lean burn SI turbocharged engines fuelled by natural gas.
2004-03-08
Technical Paper
2004-01-1784
Ashley L. Dunn, Gary J. Heydinger, Giorgio Rizzoni, Dennis A. Guenther
This paper discusses the derivation and validation of planar models of articulated vehicles that were developed to analyze jackknife stability on low-μ surfaces. The equations of motion are rigorously derived using Lagrange's method, then linearized for use in state-space models. The models are verified using TruckSim™, a popular nonlinear solid body vehicle dynamics modeling package. The TruckSim™ models were previously verified using extensive on-vehicle experimental data [1, 2]. A three-axle articulated model is expanded to contain five axles to avoid lumping the parameters for the drive and semitrailer tandems. Compromises inherent in using the linearized models are discussed and evaluated. Finally, a nonlinear tire cornering force model is coupled with the 5-axle model, and its ability to simulate a jackknife event is demonstrated. The model is shown to be valid over a wide range of inputs, up to and including loss of control, on low-and-medium-μ surfaces.
2004-03-08
Technical Paper
2004-01-1785
Ashley L. (Al) Dunn, Gary J. Heydinger, Giorgio Rizzoni, Dennis A. Guenther
The widely used Extended Kalman Filter (EKF) is applied to a planar model of an articulated vehicle to predict jackknifing events. The states of hitch angle and hitch angle rate are estimated using a vehicle model and the available or “measured” states of lateral acceleration and yaw rate from the prime mover. Tuning, performance, and compromises for the EKF in this application are discussed. This application of the EKF is effective in predicting the onset of instability for an articulated vehicle under low-μ and low-load conditions. These conditions have been shown to be most likely to render heavy articulated vehicles vulnerable to jackknife instability. Options for model refinements are also presented.
2004-03-08
Technical Paper
2004-01-1729
Daichi Kunishi, Noboru Kikuchi
In FOA (First Order Analysis) any vehicle body structure might be interpreted as a collective simple structure that can be decomposed into 3 fundamental structure types. The first structure is the “BEAM”, whose cross sectional properties as well as its material dominates the mechanical behavior, the second is the “PANEL (shear panel, plate, and shell)”, whose mechanical behavior can be varied by changing its geometrical properties in the thickness direction, i.e. adding beads or flanges. The third structure is the “JOINT”, which connects the proceeding structures, and transfer complex three-dimensional loads with three-dimensional deformation. In the present work, we shall propose a methodology to identify a portion of an arbitrary FE model of an automotive body structure, with a “BEAM” structure in the FOA approach. In the latter chapter of this paper, cross section loads will be related with cross sectional properties in the aspect of the element strain energy concept.
2004-06-08
Technical Paper
2004-01-1891
Philip R. Scinto
The Lubricant Test Monitoring System (LTMS) is the calibration system methodology and protocol for North American engine oil and gear oil tests. This system, administered by the American Society for Testing Materials (ASTM) Test Monitoring Center (TMC) since 1992, has grown in scope from five gasoline engine tests to over two dozen gasoline, heavy duty diesel and gear oil tests ranging from several thousand dollars per test to almost one-hundred thousand dollars per test. LTMS utilizes Shewhart and Exponentially Weighted Moving Average (EWMA) control charts of reference oil data to assist in the decision making process on the calibration status of test stands and test laboratories. Equipment calibration is the backbone step necessary in the unbiased evaluation of candidate oils for oil quality specifications.
2004-03-08
Technical Paper
2004-01-1009
Johannes Reuter, Utz-Jens Beister, Ning Liu, Dave Reuter, Bill Eybergen, Mohan Radhamohan, Alan Hutchenreuther
Fuel cell systems emerge as a new technology, which is expected to play an important role for future powertrain applications. To enable this technology's entrance into the market, new developments to improve robustness, cost efficiency and maintainability are necessary. Besides the stack itself, several subsystems are required to operate a fuel cell system. The technical challenges for developing and optimizing these subsystems are comparable to the challenges in the stack development itself. The air delivery system is considered to have a major impact, subject to overall efficiency, noise emissions and costs. These properties are determined not only by the system hardware, but also by the chosen control strategy. This paper describes an intelligent model based control strategy, which enables the system to use optimal operation points of compressor and motor. The quantities to be controlled are air mass flow and pressure.
2004-03-08
Technical Paper
2004-01-1241
Rudi Lenzen
Abstract Submitting Inertial Sensors to high g levels at high frequencies and measuring their response in a reproducible way is directly link with acoustic fields and waves propagation in solid theories. Key parameters like the material structure, shock system, shapes, test block dimension are considered. Correlations between theory and experimental results are addressed allowing proposing an adequate and reproducible test methodology.
2004-03-08
Technical Paper
2004-01-1227
Akira Higashimata, Kazutaka Adachi, Satoshi Segawa, Nobuo Kurogo, Hironobu Waki
Lock-up operation of an automatic transmission is known as one good method of improving fuel economy. However, locking up the transmission at low vehicle speeds can often cause undesirable vibration or booming noise. Slip control of the lock-up clutch can resolve these problems, but the speed difference of the lock-up clutch needs to be controlled at a certain value. This control system has to overcome large changes in the parameters of the lock-up system at low vehicle speeds and also changes with regard to the speed ratio in a continuously variable transmission (CVT). In this study, this complex non-linear system has been modeled as a first-order linear parameter varying (LPV) system. A robust control algorithm was applied taking various disturbances into account to design a new slip lock-up control system.
2004-03-08
Technical Paper
2004-01-1230
Syed T. Razzacki
1.0 Abstract The manual transmission synchronizer design has been a real challenge and is usually referred to as a myth and black magic. A mathematical algorithm and dimensioning and tolerancing scheme has been developed to dispel this myth. A unique and logical user-friendly method for designing synchronizer is devised. The knowledge that existed in the public domain is advanced to higher level to show that the design and calculations of physical parameters must go hand in hand. The paper attempts to demonstrate the fact that the calculations of synchronizer physical parameters should be supported by scrupulously dimensioning and tolerancing the components design to achieve the intended functional objective. A mathematical algorithm is developed which facilitates establishing the sleeve and blocker ring pointing angle relationship with the synchronizer size, coefficient of friction, cone torque, and index torque.
2004-03-08
Technical Paper
2004-01-1318
Wang Gui-hua, Yao Zhang-tao, Liu Na, Huang Xue-zheng
It is known that the electronic-controlled fuel injection technique can bring better performance characters for diesel engines. So, more and more engines have been equipped with this new fuel injection system. The radial tolerance of precise fitting pieces in electronic-controlled high-pressure-common-rail fuel injection system of diesel engine will affect the performance and life of fuel injection system greatly. Now, the tolerance is usually chosen only by experience. In this paper, based on the fluid theory of laminar flow in slit flow way, the optimal formulas of radial tolerance for least sum of fluid leakage and viscous friction energy consumption have been established. Also a calculation example has been listed.
2004-03-08
Technical Paper
2004-01-1310
Jeff Howell
Road vehicles operate almost entirely in the unsteady conditions created by the natural wind and the wakes of other vehicles. This is a time dependent and turbulent environment, which differs noticeably from the conditions simulated in the wind tunnel. Using a quasi-steady analysis the aerodynamic characteristics, as determined from wind tunnel tests, are used to derive the unsteady aerodynamic loads experienced by a typical road vehicle subjected to a random wind input. For this paper the wind energy spectrum is of the von Karman type and isotropic turbulence is assumed. The effects of vehicle speed, wind speed and wind direction on lift and side force spectra are presented.
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
2004-01-0619
F. Bozza, A. Gimelli, D. Siano, E. Torella, G. Mastrangelo
The paper reports the research activity related to the development of a twin-spark SI engine equipped with a variable valve timing (VVT) device. Improvements on the fuel consumption at part load are expected when an high internal exhaust gas recirculation (internal EGR) level is realized with a proper phasing of the VVT device. The twin-spark solution is implemented to improve the burning speed at low load, and to increase the EGR tolerance levels. Both experimental and theoretical analyses are carried out to investigate the real advantages of the proposed engine architecture. In particular an original quasi-dimensional model for the simulation of the burning process in a twin-spark engine is presented. The model is mainly utilized to find the proper combination of VVT device position (and hence EGR level) and spark advance for different engine operating conditions. A comparison with the single-spark solution is also provided.
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