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Viewing 1 to 30 of 5094
2010-04-12
Technical Paper
2010-01-1111
Karthikeyan Natchimuthu, Jayanthamani Sureshkumar, V. Ganesan
Increasing the efficiency of engine auxiliary systems have become a challenge. Oil pump, identified for this study, is one such engine system which is used for lubrication of engine parts. To achieve higher efficiencies, there is a need for math-based analysis and design. This can be achieved by means of Computational Fluid Dynamics (CFD). The main aim of this paper is to simulate the flow through Gerotor Oil pump using Computational Fluid Dynamics. A 3D model of the entire flow domain is created and meshed in preprocessor GAMBIT. The mesh for various pressure outlet conditions is exported to FLUENT solver for analysis. The predicted results are validated with the experimental results. The comparison shows that the CFD predictions are in good agreement with experimental results. In particular, such a simulation offers a scope for visualizing the flow through the Gerotor oil pump.
2011-04-12
Technical Paper
2011-01-0013
June-Young Song, Kangwook Lee, Byung-Jae Ahn
The main role of CAB(side curtain airbag) is to protect the occupant's head in the event of side crash. The updated US NCAP for model year 2010 requires more extended coverage of CAB. It is not only required to cover the 50th%ile driver but also the 5th%ile driver and rear passenger. Although the general safety analysis model using only concerned sub-structure of the vehicle and prescribed structural motion is sufficient to handle frequent jobs, the analysis model with increased efficiency is needed when optimization is to be studied as it requires more runs and the model gets enlarged to consider extended sub-structure. In this study, three types of simplified analysis models are introduced. The first has an impactor which is composed of the head and neck with prescribed translational motions. It only uses the upper parts of the original sub-structure hence the run time is saved by 60∼70%.
2011-04-12
Technical Paper
2011-01-0210
Yu-Sung Chen, Jia-Xiu Liu, Chung-Chih Tsai, Chia-Tseng Chen
This study proposes an anti-counterfeiting system of drunk driving, which prevents drivers from drunken driving and cheat of driver's alcohol detection. The study develops the technology of driver's facial image match by a serial image processes. The methodology of facial image match uses the Adaboost algorithm, Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) to extract the facial features of drivers, is suitable to be applied under the internal environments of cabin. By analyzing the facial features of drivers, the time of driver's exchange is detected, and the driver's identity is indentified. When the cheat act of driver's alcohol detection occurred, the system will generate warning signals through a buzzer to notice the driver to take alcohol detection.
2011-04-12
Technical Paper
2011-01-0176
Sinisa Krajnovic
The paper discusses an appropriate usage of large eddy simulation (LES) in external vehicle aerodynamics. Three different applications, wheelhouse flow, gusty flow and active flow control, are used to demonstrate how LES can be used to obtain new knowledge about vehicle flows. The three examples illustrate the information that can be extracted using LES in vehicle aerodynamics and show the potential of LES in explorations of this complex flow.
2011-04-12
Journal Article
2011-01-0162
Ming Jiang, Huaizhu Wu, Kebing Tang, Minsuk Kim, Sivapalan Senthooran, Heinz Friz, Yingzhe Zhang
The engineering process in the development of commercial vehicles is facing more and more stringent emission regulations while at the same time the market demands for better performance but with lower fuel consumption. The optimization of aerodynamic performance for reduced drag is a key element for achieving related performance targets. Closely related to aerodynamics are wind noise and cabin soiling and both of them are becoming more and more important as a quality criterion in many markets. This paper describes the aerodynamic and aero-acoustic performance evaluation of a Dongfeng heavy truck using digital simulation based on a LBM approach. It includes a study for improving drag within the design of a facelift of the truck. A soiling analysis is performed for each aerodynamic result by calculating the accumulation of particles emitted form the wheels on the cabin. One of the challenges in the development process of trucks is that different cabin types have to be designed.
2013-11-20
Journal Article
2013-01-9121
Kristian Haehndel, Torsten Frank, Frieder Christel, Sylvester Abanteriba
Within the pre-development phase of a vehicle validation process, the role of computational simulation is becoming increasingly prominent in efforts to ensure thermal safety. This gain in popularity has resulted from the cost and time advantages that simulation has compared to experimental testing. Additionally many of these early concepts cannot be validated through experimental means due to the lack of hardware, and must be evaluated via numerical methods. The Race Track Simulation (RTS) can be considered as the final frontier for vehicle thermal management techniques, and to date no coherent method has been published which provides an efficient means of numerically modeling the temperature behavior of components without the dependency on statistical experimental data.
2013-09-24
Technical Paper
2013-01-2368
Harish Harinarayanan
Commercial vehicle payload depends on the client for which the vehicle fleet owner is operating. Load carriers like flatbed trailer offer the flexibility to be loaded with a large number of light payloads or a few numbers of massive payloads. Such load carriers have to be evaluated for various possibilities of loading patterns that could happen in the market. The objective of this work is to evaluate flatbed trailer for its structural strength for different customer application cases, using computer simulation. Structural load cases due to payloads like containers, steel coils and cement bags are arrived at. Static structural analysis using MSC Nastran is performed to evaluate for the worst customer loading pattern from structural stress point of view. This paper also describes a simplified method for simulating the effect of trailer suspension, tractor suspension and the fifth-wheel coupling in the analysis whose detailed modeling is not possible at the concept level.
2004-03-08
Technical Paper
2004-01-0336
Naoki Kaneko, Masayuki Wakamatsu, Masanobu Fukushima, Shigeru Ogawa
Development of anti-whiplash technology is one of the hottest issues in the automotive safety field because of the frequent occurrence of rear impact accidents. We analyzed the whiplash mechanism and conducted a study to seek the optimized seat characteristics with BioRID II and MADYMO simulations. A parameter study was made to construct a conceptual theory to decrease NIC, Neck Injury Criteria, with the MADYMO model. As a result of the study, head restraint position and seatback stiffness were found to affect dummy movement and injury values. Applying the NIC mechanism and the influential parameters to the MADYMO model, the optimized seat characteristics for whiplash prevention were obtained.
2004-03-08
Technical Paper
2004-01-0340
M. Kröninger, R. Lahmann, T. Lich, M. Schmid, H. Güttler, T. Huber, K. Williams
This paper describes a new system for early detection of tripped rollover crashes. The main goal of this system is to improve the protection of restraint devices, such as curtain window bags, in these rollover situations. This is achieved by a new rollover sensing (RoSe) algorithm in the airbag controller which produces a very early and robust deployment decision. Based on the analysis of tripped rollover test data, this paper shows how improved rollover sensing performance can be achieved by considering information about the vehicle's driving state before the rollover occurs. The results of this new approach are discussed in terms of deployment times. Finally a combined active and passive safety system architecture for the realization of the approach is suggested.
2004-03-08
Technical Paper
2004-01-0341
Hermann Steffan, Andreas Moser
Due to the increasing number of minivans and sport utility vehicles, rollovers have become more significant. As a result, various accident reconstruction programs have been developed to address this issue. To reconstruct rollover crashes, various requirements have to be fulfilled. These consist of: providing a simple method that is able to model three dimensional environments that often play a major role in rollovers. including suspension, tire and collision models must be provided. This is particularily important in the rollover initiation phase. including proper vehicle geometry and contact stiffness must be available. These are important for simulation of body contacts that affect the vehicle motion. This study focuses on one program, PC-CRASH. This program was developed to allow simulations of vehicle 3-dimensional movements before, during and after the impact. The study also discusses the physical background of the models, their capabilities as well as their limitations.
2004-03-08
Technical Paper
2004-01-0350
Suzanne Tylko, Dainius Dalmotas
The responses of a 5th percentile female ATD in the driver and/or rear passenger positions of 56 crashes are described. The Transport Canada side impact programme consisted of LTV-to-car impacts, car-to-car impacts and IIHS barrier-to-car tests. The majority of the tests involved severe crash conditions for which the vehicles were not designed. The SID-IIs head, chest and abdominal responses were compared to determine the effects of the striking bullet geometry, the angle of impact, the impact point and the self-protective elements of the struck vehicle, including airbag technology and armrest designs. The SID-IIs head responses and deflection measures were sufficiently sensitive to discriminate between the various striking vehicles, crash configurations, airbag systems and armrest characteristics.
2004-03-08
Technical Paper
2004-01-0381
Vivek Bhise, Ghassan Kridli, Huzefa Mamoola, Shawn Devaraj, Anitha Pillai, Roger Shulze
This paper describes a research project currently in-progress to develop a parametric model of a vehicle for use in early design stages of a new vehicle program. The model requires key input parameters to define the kind of new vehicle to be designed — in terms of details such as its intended driver/user population, vehicle type (e.g. 2-box, 3-box designs), and some key exterior and interior dimensions related to its size and proportions. The model computes and graphically displays interior package, ergonomics zones for driver controls and displays, and field of views through window openings. It also allows importing or inputting and superimposing and manipulating exterior surfaces created by a designer to assess compatibility between the interior occupant package and the vehicle exterior.
2004-03-08
Technical Paper
2004-01-0370
Arthur L. Richards, Vivek D. Bhise
Programmable vehicle models (PVMs) are intended to save time and costs in building bucks to evaluate vehicle interior packages. This paper presents results from a series of three studies conducted to determine the applicability and limitations of the methodology of using a PVM. The PVM used for the study was built by Prefix Corporation and has forty-two axes of adjustments. The first study verified the PVM's ability to reproduce dimensions. It showed that the PVM was acceptably accurate, with most dimension measurement ranges less than 2-3 mm. The second study was conducted to determine if subject responses are reliable indicators of package differences. Aside from some special causes, most were found to be. The third study was conducted to determine how well the PVM replicated 3 actual vehicles. Despite some dimensional discrepancies, there was evidence of correlation between subject responses from the PVM and actual vehicles.
2004-03-08
Technical Paper
2004-01-0451
Marita Irmscher, Martin Ehmann
A driver model is presented that accounts for individual driver behavior and allows driver classification or behavior for common driving tasks. Typical driver errors can be modeled by means of parameters of the driver controller and by influencing the driving course. This is illustrated for some typical driver types and driving maneuvers.
2004-03-08
Technical Paper
2004-01-1507
E.C. Chan, G. Karimi, D. Rose, J.R. Culham
This paper presents a comprehensive steady-state numerical study for an occupant-loaded vehicle seat with internal heating under severe winter conditions. A participant-based postural study showed that the nominal peak occupant seat pressure was 6kPa on the seat cushion, and 2.5kPa on the backrest. Uni-axial compression tests also indicated non-linear stress-strain behaviors in seating. Using an internally developed 3-D numerical model, it was found that the thermal resistance from contact and clothing was uniform (hc=144W·K−1·m−2) throughout the occupied regions. Their contribution to the overall thermal resistance was relatively minor, however, compared to that of skin (hoverall=27.2W·K−1·m−2). The thermal-mechanical simulations were conducted at heat input levels between 20W and 80W, using I-DEAS 10 and the TMG package as the simulation platform. Comparisons was also made between occupied seat with deflected and non-deflected mesh.
2004-03-08
Technical Paper
2004-01-1509
Gaurav Anand, Milind Mahajan, Nagendra Jain, Balaji Maniam, Todd M. Tumas
e-Thermal is a vehicle level thermal analysis tool developed by General Motors to simulate the transient performance of the entire vehicle HVAC and Powertrain cooling system. It is currently in widespread (global) use across GM. This paper discusses the details of the air-conditioning module of e-Thermal. Most of the literature available on transient modeling of the air conditioning systems is based on finite difference approach that require large simulation times. This has been overcome by appropriately modeling the components using Sinda/Fluint. The basic components of automotive air conditioning system, evaporator, condenser, compressor and expansion valve, are parametrically modeled in Sinda/Fluint. For each component, physical characteristics and performance data is collected in form of component data standards. This performance data is used to curve fit parameters that then reproduce the component performance.
2004-03-08
Technical Paper
2004-01-1454
Thomas Resch, Borislav Klarin
The target of dynamic simulation is to investigate complex engine dynamic behavior in the whole speed range under different loading conditions in the most effective way during Engine Development Process (EDP). AVL has developed a method for transient run-up analysis by using the simulation tool AVL EXCITE. The main objective of this new method is the controlled speed increase by defining a speed ramp. Transient run-up analysis is of interest for different kind of analysis during the EDP, such as crankshaft dynamics and strength, low frequency vibration analysis, bracket strength and durability analysis, acoustic analysis, etc. By using this method the time required for simulations and thus the whole project duration is significantly reduced. Conventionally the speed range is divided in single speed steps and for each speed a separate transient simulation has to be performed. The number of these simulations depends on the required speed resolution.
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
2004-01-1477
Zoran Filipi, Loucas Louca, Anna Stefanopoulou, Jay Pukrushpan, Burit Kittirungsi, Huei Peng
This paper investigates the opportunities for improving truck fuel economy through the use of a Fuel Cell Auxiliary Power Unit (FC APU) for silent watch, as well as for powering electrified engine accessories during driving. The particular vehicle selected as the platform for this study is a prototype of the Family of Medium Tactical Vehicles (FMTV) capable of carrying a 5 ton payload. Peak stand-by power requirements for on-board power are determined from the projected future digitized battlefield vehicle requirements. Strategic selection of electrified engine accessories enables engine shutdowns when the vehicle is stopped, thus providing additional fuel savings. Proton Exchange Membrane (PEM) fuel cell is integrated with a partial oxidation reformer in order to allow the use of the same fuel (JP8) as for the propulsion diesel engine.
2004-03-08
Technical Paper
2004-01-1474
Syed Wahiduzzaman, Babajide Kolade, Selim Buyuktur
The potential of fuel cells as an automotive power source is well recognized due to their high efficiency and zero tailpipe emissions. However, significant technical and economic hurdles need to be overcome in order to make this technology commercially viable. A proton-exchange membrane (PEM) fuel cell model has been developed to assess some of these technical issues. The fuel cell model can be operated in a standalone mode or it can be integrated with vehicle and fuel supply system models. A detailed thermal model of the fuel cell stack was used to identify significant design parameters that affect the performance of PEM fuel cell vehicles. The integrated vehicle model was used to explore the relative benefits of hybridization options.
2004-03-08
Technical Paper
2004-01-1468
Nils Johnson
The Balance of Plant design process for PEM fuel cell systems is a complicated task. A typical PEM fuel cell system includes components from multiple engineering disciplines, such as hydration systems, sensors, pumps, motors, compressors, power electronics, and heat exchangers. The design process of a complete fuel cell system must integrate these mixed-technology components into a single design. Simulation is valuable tool for use in the design process of fuel cell systems. This paper describes development of a mixed-technology PEM fuel cell simulation model developed for the purposes of fuel cell Balance of Plant design and system integration.
2004-03-08
Technical Paper
2004-01-1727
Jean Ma, Yi Zhang, Don Jagos
Hood opening/closing is a necessary function in a vehicle, but the closing often results in an impact known as hood slam. The damage to the components of the FEM (Front End Module), induced by the hood slam, accumulates over the vehicle lifetime and may lead to failure. In a traditional design process, an impact test is conducted on prototype FEM to evaluate its integrity. It is, however, very costly and time-consuming to achieve a statistical based confidence. Presented in this paper is a methodology of CAE hood-slam simulation that intends to replace the test and drive FEM design. This CAE method includes two aspects: impact simulation and fatigue life evaluation. An impact loading is applied by converting potential energy to kinetic energy, mimicking the hood dropping from a specified height on the hood latch. The impact loading causes the local deformation and stress concentration, which may become potential failure spots.
2004-03-08
Technical Paper
2004-01-1001
A. Onorati, G. Ferrari, G. Montenegro, A. Caraceni, P. Pallotti
The paper describes the research work carried out on the thermo-fluid dynamic modeling of an S.I. engine coupled to the vehicle in order to predict the engine and tailpipe emissions during the ECE European driving cycle. The numerical code GASDYN has been extended to simulate the engine + vehicle operation during the first 90 seconds of the NEDC driving cycle, taking account of the engine and exhaust system warm-up after the cold start. The chemical composition of the engine exhaust gas is calculated by means of a thermodynamic multi-zone combustion model, augmented by kinetic emission sub-models for the prediction of pollutant emissions. A simple procedure has been implemented to model the vehicle dynamic behavior (one degree of freedom model). A closed-loop control strategy (proportional-derivative) has been introduced to determine the throttle opening angle, corresponding to the engine operating point when the vehicle is following the ECE cycle.
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
2004-01-1264
Eric Rask, Mark Sellnau
Calibration of engine management systems requires considerable engineering resources during the development of modern engines. Traditional calibration methods use a combination of engine dynamometer and vehicle testing, but pressure to reduce powertrain development cost and time is driving development of more advanced calibration techniques. In addition, future engines will feature new technology, such as variable valve actuation, that is necessary to improve fuel economy, performance, and emissions. This introduces a greater level of system complexity and greatly increases test requirements to achieve successful calibrations. To address these problems, new simulation tools and procedures have been developed within Delphi to rapidly generate optimized calibration maps. The objective of the work is to reduce calibration effort while fully realizing the potential benefit from advanced engine technology.
2004-03-08
Technical Paper
2004-01-1239
John Limroth, Ali Rahbar, Borz Faribozi
The increasing use of rapid prototyping and hardware-in-the-loop (HIL) testing in the design process for embedded control applications motivates the need for a standard, portable, scalable real-time system that interfaces to control design software. This paper will discuss tools that are used to implement control designs and simulation models in real-time, as well as a case study of one such application. In addition, the paper will discuss tradeoffs between the use of the same real-time platform for both control prototyping and hardware-in-the-loop simulation and the use of different platforms for each task. The tradeoffs between the use of custom solutions for these applications and the use of commercial off-the-shelf hardware will also be discussed.
2004-03-08
Technical Paper
2004-01-1238
Hamid A. Oral, Kevin White, Yin Wen
This paper presents a uniquely integrated environment where a control system is modeled, simulated and implemented in real time requiring no coding, no compiling nor embedding for multiple test rigs. The novel hardware architecture simultaneously configures itself according to the contents of a visual configuration editor (VCE) that is put together by the user utilizing graphical representations of basic building blocks called primitives. Similar to an analog computer, as the user builds the VCE model, the “code is simultaneously compiled and embedded” into the target DSP processor/s as easy as dragging and dropping primitives from various libraries into the VCE and connecting them. Similarly DSP processors within the hardware network are visually available to the user to be dropped into the VCE creating a distributed multi-processor control environment. The execution of multiple DSPs take place simultaneously reaching 25.6 kHz loop rates and 200 kz sampling rates.
2004-03-08
Technical Paper
2004-01-1225
Aniello Forcelli, Corrado Grasso, Teresa Pappalardo
In this paper a new testing methodology has been developed to objectively measure the gear rattle noise. This kind of noise has become very important especially since car manufacturers have pointed their attention to the engine noise reduction. In fact, when efforts are focused to reduce engine noise, the gearbox noise becomes more audible. This article describes the experimental analysis that has been made to measure transmission gear rattle noise on an innovative NVH (Noise, Vibration & Harshness) transmission test rig. Also, emphasis on the capability of the test rig set-up to decouple the gear rattle noise from other vehicle noises is presented. Using such set-up, the gear rattle problem is pronounced and, consequently, noise investigation becomes easier and objective unlike what happens in a vehicle or in the power train test cell. In order to obtain reliable results from this test rig, its performance has been correlated to measurements performed on the car.
2004-03-08
Technical Paper
2004-01-1229
Andrzej Szadkowski
Clutches possessing levers are prevalent in the North American market of medium and heavy duty trucks. The purpose of this paper is to investigate dynamic and kinematic problems related to clutch levers. Clutch designers are primarily concerned with the effects of levers on clamp load in the engaged state of the clutch, but neglect or downplay consequences of dynamic effects on the release properties of clutches. The paper focuses on the release aspect of levers although the clamp load is also considered. The research method used in this paper was based on mathematical modeling and simulation of engagement and release processes. Main issues studied include: Lever ratio varies both during the bearing departure and with wear of the clutch. The lever ratio variation affects both the lift of the pressure plate and the clutch clamp load. The simulation model can be utilized to optimize both lever shape and lever positioning during the entire clutch life.
2004-03-08
Technical Paper
2004-01-1207
Terry D. Day
SIMON is a new 3-dimensional vehicle dynamic simulation model. The capabilities of the model include non-linear handling maneuvers and collision simulation for one or more vehicles. As a new model, SIMON must be validated by comparison against actual handling and collision experiments. This paper provided that comparison. Included in the validation were lane-change maneuvers, alternate ramp traversals, limit maneuvers with combined braking and steering, vehicle-to-vehicle crash tests and articulated vehicle handling tests. Comparison against other models were included. No metric was provided for handling test comparisons. However, statistical analysis of the collision test results revealed the average path range error was 6.2 to 14.8 percent. The average heading error was -4.7 to 0.7 percent. Delta-V error was -1.6 to 7.5 percent. VEHICLE SIMULATION has many uses in the vehicle design and safety industries.
Viewing 1 to 30 of 5094

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