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2012-06-13
Technical Paper
2012-01-1537
In industrial automotive transmissions, several noises can't be avoided such as gear rattle and gear whine noises. Indeed they result from the choice of gear technology. They just can be reduced by an appropriate design. It is widely acknowledged that gear whine noise is mainly due to transmission error, which depends on many parameters such as driveshaft deflection, gear stiffness and operating torque. All these parameters are not necessarily well-known, which may sometimes result in the choice of a gear geometry that doesn't minimize transmission error. That can lead to customer claims once the vehicle is manufactured. To cope with whine noise customer claims, we investigated a statistical gear optimization method. The principle is to use whine measurement data base on benches to find the best geometry against whine noise after a statistical treatment. The main advantage is that it is not necessary to know precisely all the parameters involved in whine noise.
2015-01-30
Book
This set consists of two books, Design of Automotive Composites and CAE Design and Failure Analysis of Automotive Composites, both developed by Dr. Charles Lu and Dr. Srikanth Pilla. Design of Automotive Composites reports that successful designs of automotive composites occurred recently in this arena.
1990-02-01
Technical Paper
900255
Shigeki Sugiura, Toshio Yamada, Tokuta Inoue, Koji Morinishi, Nobuyuki Satofuka
Multi-dimensional code has been developed to simulate the effect of geometry on mass flow rate and flow pattern in the induction system of an internal combustion engine. The unsteady compressible Navier-Stokes equations in general curvilinear coordinates are solved by a new method of lines. In the method of lines, the governing equations are spatially discretized by a finite difference approximation and the resulting system of ordinary differential equations is integrated. As a time integration scheme, we newly propose to use the rational Runge-Kutta scheme in order to efficiently simulate the flows in the induction system. The domain-decomposition technique is introduced so that body-fitted structured grid can be easily generated for such complex geometry as a real intake port shape. The present code is applied to 2 and 3 dimensional steady flows in intake port/cylinder assembly with a valve.
1990-02-01
Technical Paper
900251
MarK J. Jennings, Thomas Morel
An important aspect of calculation of engine combustion chamber heat transfer with a multi-dimensional flow code is the modeling of the near wall flow. Conventional treatments of the wall layer flow employ the use of wall functions which impose the wall boundary conditions on the solution grid points adjacent to solid boundaries. However, the use of wall functions for calculating complex flows such as those which exist in engines has numerous weaknesses, including dependence on grid resolution. An alternative wall modeling approach has been developed which overcomes the limitations of the wall functions and is applicable to the calculation of in-cylinder engine flows. In this approach the wall layer flow is solved dynamically on a grid spanning a very thin boundary layer region adjacent to solid boundaries which is separate from the global grid used to solve the outer flow.
1990-02-01
Technical Paper
900253
D. H. Gibson, W. A. Mahaffey, T. Mukerjee
This paper details the development of a mathematical model to simulate the incylinder processes in the Caterpillar 1.7L Diesel engine and the results obtained during compression stroke and early part of the combustion stroke. The model includes accurate representation of the geometry of the 1.7L combustion chamber via Body Fitted Coordinates (BFC) which conform to the shape of the piston-dish and cylinder. Also included are the combustion model and evaporation model. This 3-D model predicts average cylinder pressure and temperature variations with degree crank angle which are in good agreement with Caterpillar measurements for this engine.
1990-02-01
Technical Paper
900252
Kang Y. Huh, I-Ping Chang, Jay. K. Martin
- Three different models, the law-of-the-wall, a modified law-of-the-wall, and an approximate one-dimensional solution to the energy equation are compared for the spatially-resolved prediction of engine heat tranfer. The multidimensional hydrodynamic code KIVA is used for the fluid mechanic simulation. Two different engine geometries are studied; one being a pancake-shaped chamber, and the other a bowl-in-piston geometry. The comparisons are done for a range of initial conditions of gas flow. Rates-of-pressure-rise were also varied to represent rates typical of those encountered in motored engines, and those found in fired engines. Comparisons with experimental results show that the heat transfer predictions using the law-of-the-wall may be in error when source terms such as the transient, work and chemical energy terms have a significant effect in determining the temperature profile in the boundary layer.
1990-02-01
Technical Paper
900242
Munehiro Karasudani, Shinji Miyata, Kazuyuki Doi, Naotoshi Higashiyama
1 ABSTRACT Currently, digital audio source such as a compact disk (CD) and a digital audio tape (DAT) has come to be mounted in cars to complement the sophisticated audio system . To mount these new functions in the limit set space, however, the conventional source such as the FM/AM tuner must be built more compact and lightweight. On the other hand, to view the FM/AM tuner perspective from the standpoints of set design and manufacture, there are various problems such as given below. Set variations are flung from those for the U.S.A. and Europe to those for Japan. It is difficult, if not impossible, to design the set designer for each of these set variations because of the limited designer availability. Also, amid the tendency for world production base to be spread and increasingly numerous, high quality level is of the utmost importance for audio sets no matter where are manufactured. This paper describes an effective solution to these problems.
1990-02-01
Technical Paper
900464
Ken Nakagawa, Tatsuhiro Ootsubo
It is becoming more and more complex and time consuming to have a newly developed vehicle meet the safety requirement these days. On the other hand, with the aid of computers and software technology, detailed crash simulation are possible. ISUZU MOTORS LTD. has applied these to the passenger car from the early stages of development in order to optimize the car's behavior in the 35MPH frontal barrier test. Crash simulations were performed by using the detailed full vehicle FEM model and the crash simulation program PAM-CRASH. This simulation focussed on the collapsing mode of the front structure, especially on the front of the side rails and the attached parts. Section forces, accelerations, and deformed shapes were investigated and optimized to improve energy absorption. The effect was confirmed by the experimental barrier test. This procedure contributed greatly to reducing the time required for development as well as the number of prototype vehicles needed.
1990-02-01
Technical Paper
900470
Paul Green, John Boreczky, Seung-Yun (Sylvia) Kim
To develop easy-to-use control panels, it is essential to measure driver performance, compare it with behavioral specifications, modify the design based on driver feedback, and then retest. Rapid prototypers help engineers do this quickly. This paper identifies the I/O capabilities, ease of use, ability to record user behavior, and real-time performance for several prototypers. Two example HyperCard prototypes are described here. The first, a car clock, shows how HyperCard can vary button size and location, labeling, auditory feedback, and the mapping of switches to system functions. The second, a car radio, shows that continuous controls and digitized sound can be handled.
1990-02-01
Technical Paper
900466
J. C. Liaw, A. C. Walton, J. C. Brown
Use is made of the KRASH program to simulate a simplified car-into-barrier impact. A step-by-step modelling technique is illustrated whose application at an early stage in the design process, allows an understanding of the contribution of individual components to the overall crash-performance of a vehicle.
1990-02-01
Technical Paper
900463
Tomohiko Ariyoshi
To analyze the rear end crash of a motor vehicle using a beam-element model, it is important how to model the upper body panel members such as rear doors or rear quarters. This paper describes the method of modeling each panel member into a beam element considering the “effective areas” in each member section. The panel member is cut into several sections along its longitudinal axis. Applying the thin-shell buckling theory and experimental analysis to each section, “effective areas”, which withstand up to the yield stress when the panel member is subjected to longitudinal compression, can be selected. With the section characteristics of the “effective areas”, a beam element for the panel member is defined. The results of the calculation by this method showed a good correlation to the experimental results of three kinds motor vehicles with the body deformation mode or crash length etc.
1990-02-01
Technical Paper
900462
Tomasz Wierzbicki, Wlodek Abramowicz
CRASH-CAD is a commercially available computer aided design package that specifically addresses design problems of components and sub-assemblies of automotive bodies subjected to crash loading. The program is fully interactive and leads an engineer in several steps towards an improved crashworthy design. The objective of the present paper is to give a theoretical foundation of this new computer program and demonstrate its various capabilities. CRASH-CAD enjoys unparalleled modelling simplicity. It requires only basic cross-sectional dimensions of a given member and a discretization into Superfolding Elements is done automatically. The current version of CRASH-CAD is applicable to prismatic members subjected to predominantly axial compressive loads.
1990-02-01
Technical Paper
900469
Richard C. Berry
Application-independence is the key to reusability and universal interfacing of dot matrix display subsystem designs. Special design rules can be applied during the development of these systems that promote the removal or localization of all application-specific components, resulting in display products that can be applied without modification to many varied applications.
1990-02-01
Technical Paper
900471
Jiro Tanaka, Kazuo Hirano, Hiroaki Nobuta, Toshiyoki Itoh, Sellchi Tsunoda
This paper describes a navigation System for private automobiles. This system shows the accurate position of the vehicle on a CRT map display and also displays useful Information such as the locations of hotels, golf clubs, etc. A sophisticated map matching method is employed to find the vehicle's position. In this method, a set of correlation coefficients between the locus and the mapped roads is used to determine the vehicle's location statistically. A unique automatic calibration function is also added to the magnetic field sensor to compensate for malfunctioning and detection errors caused by distortion due to the earth's magnetism and to magnetization of the vehicle at points of high field density such as railroad crossings. In this system, we can see the current position of the vehicle indicated by a pointer on the smooth scrolling map display.
1990-02-01
Technical Paper
900479
Norimasa Iida, Kou Hirawo, G. Takeshi Sato
The process of forming mixtures of injected fuels and ambient air has significant effects on the ignition and combustion process in the direct injection engine. In these engines fuel is injected intermittently and fuel jet impinges on a combustion chamber wall. This study deals with a fundamental experiment on the mixing process of the transient gas jet together with the instantaneous concentration measurement and statistical analysis of the transient turbulent mixing process in the jet. Helium or carbon dioxide is injected at constant pressure into quiescent atmosphere through the single shot device. This paper presents a laboratory automation system for measuring the characteristics of transient gas jet and processing the data. A discussion on the process of mixture formation of transient gas jets impinging on a wall is carried out with time- and space- resolved concentration distribution.
1990-02-01
Technical Paper
900422
Craig L. Andrews
The ability to injection mold thermoplastic reinforced with long glass fibers, in the range of .5 inches (12.7 mm) and with contents of up to 60% by weight, has increased the options for selecting structural materials The work reported is in support of developing technology that can be applied to bumper beam applications with possible translation to structural design of other applications. The primary focus of this work was to examine the feasibility of designing a bumper beam for a vehicle which would employ the use of energy absorbers. This design was to be based on the use of nonlinear finite element analysis to develop procedures for future design work. The effect of attachment constraints on the behavior of the basic bumper beam is examined to obtain data that can be provided to the automotive design engineer considering the use of a plastic bumper beam.
1990-02-01
Technical Paper
900445
Barbara M. Grimm, R. T. Johnson
Three simplified thermodynamic methods for calculating combustive heat release are presented. The first method requires two pressure transducers for the data collection and is generally used for a divided chamber engine. The second method is a simple thermodynamic method for single chamber engines, and the third method calculates the pressure change due to combustion, and from this pressure calculates the combustive rate of heat release. The latter two methods require data from one pressure transducer. In this study all three methods have been applied to divided chamber and single chamber diesel engines. All three methods give information about the length and type of combustion. The dual transducer method gives a slightly longer period of combustion than the other two methods but the third method, the combustion pressure method, gives the same information about the beginning of combustion as the dual transducer method.
1990-02-01
Technical Paper
900452
R. Southam, J. Reinicke-Murmann, P. Kreuter, G. Rogers
Potential improvements in spark ignited engine performance gained through the application of ceramic valve train components were predicted using state-of-the-art valve train simulation and gas exchange computer programs. The use of ceramic valves, ceramic pushrods, and ceramic hydraulic tappet housings, in combination with modified valve spring and valve lift parameters, were analyzed for a 2.8L overhead valve V-6 engine. The results show that significant improvements in dynamic valve train behavior and engine performance are possible with the largest gains coming from the use of ceramic valves. Potential improvements in valve train dynamics include: a 20% increase in maximum engine speed; a 30% reduction in the maximum valve train forces; and a 30% reduction in valve train friction. These benefits can then be used to either improve fuel economy, high speed engine power or low speed torque by up to 5%.
1990-02-01
Technical Paper
900456
S. J. Lee, B. J. Gilmore, J. E. Beard
It is well known that inappropriate dimensional tolerances can lead to diminished performance of an engine. This paper presents a method to determine the probabilistic dynamic errors of a single cylinder engine. The uncertainties considered in the analysis are tolerance on the link length, radial clearance and random pin center location. Such uncertainties create mechanical errors in the position, velocity and acceleration of the piston and crank and thus, influence the engine's performance. This research statistically determines the effect of tolerances on the global dynamic behavior of an engine. This study uses the effective link length model and adopts the Monte Carlo simulation method to determine mechanical errors in terms of standard deviations.
1990-02-01
Technical Paper
900390
Kenichi Seki, Yasuhisa Okumoto
This paper describes a simulation method used for the study of light-duty truck vibration. Building block approach (BBA) combined with the finite element method (FEM) was applied to simulate efficiently the overall dynamic behavior of a vehicle system. The frequency response function computed agreed very well with experimentally measured data of the vehicle. As a case study, this paper also reports the analysis of truck cab vibration caused by elastic vibration of the frame, concluding that the method developed was well applicable and effective to design stage. In addition, dynamic optimization technique using frame FEM model was introduced. Its output suggests the optimum place thickness distribution for the frame to keep a certain target of natural frequency.
1990-02-01
Technical Paper
900392
William H. Ewing, Hiroshi Nemoto
A computer simulation program has been developed to aid the engineer in the exhaust system noise attenuation process. This program allows for the manipulation of key component positions and configurations and predicts the resulting sound pressure level throughout the operating frequency range. This process can eliminate some of the “trial and error” approach to exhaust tuning, thus significantly reducing total development time.
1990-02-01
Technical Paper
900400
Floyd A. Wyczalek, Hideo Kawamura, Chung M. Suh
This is a descriptive review of the ceramics structural applications developed by Isuzu, Mazda, Nissan, Toyota and General Motors in spark ignition, Diesel and gas turbine automotive engines; new analytical procedures needed for the design of structural ceramics; new silicon nitride ceramics with strength of material properties approaching steel; new ceramics processing techniques which have been reduced to commercial practice in Japan on a mass production scale; and tests of vital structural components fabricated of these ceramics.
1990-02-01
Technical Paper
900402
Yhuda Tzabari, Marcel Gutman, Arthur Stotter, David Brandon
In this work, the design and testing of a silicon-nitride (Si3N4) piston-cup for a Petter AV1 laboratory diesel engine is presented. A preliminary design was first prepared and tested for thermal shock. The tests showed that non uniform displacements occurred between the ceramic plate and the piston. An improved design was then prepared, which allowed control of the characteristics of the gasket mounted between the ceramic plate and the piston. This second design was evaluated by thermal shock and exposure to cyclic pressure variation, followed by engine tests. A short description is given of the experimental set-up used for investigating the ceramic materials which are candidates for the moving parts exposed to thermal and dynamic shock in internal combustion engines. Finally two pistons with ceramic top plates were introduced in the engine with thermocouples mounted at different points of the liner and exhaust valve.
1990-02-01
Technical Paper
900403
Toshiharu Matsui, Motokazu Kobayashi, Hiroshi Okamura, Kiminari Kato, Yoshiaki Hori
The authors developed, for use in diesel engines, ceramic tappets cast in aluminum alloy that drastically improved wear resistance and valve train dynamics. The ceramic tappets consist of two parts: a ceramic head, which contacts the cam and push rod, and a tappet body made of aluminum alloy. Concerning the ceramic, silicon nitride was the best material of the three ceramics evaluated in the tests and the sliding surface, in contact with the cam and push rod, was left unground. As for the aluminum alloy, hyper-eutectic aluminum-silicon alloy with a controlled pro-eutectic silicon size was selected. A reliability analysis using the finite-element method (FEM) was also made on the structure of the ceramic tappet for enhanced durability and reliability. The combination of this tappet and a cam made of hardened ductile cast iron, hardened steel, or chilled cast iron, respectively exhibits excellent wear resistance.
1990-02-01
Technical Paper
900415
Randa A. Radwan, William T. Hollowell
A formulation is presented that augments a recently developed method for determining the nonlinear stiffness and damping characteristics of structures subjected to crash-loading environments. The system identification is accomplished using adaptive time domain, constrained minimization techniques. The structural characteristics are idealized with piecewise linear segments and, in the new formulation, the stiffness and damping characteristics are postulated to be functionally dependent. The inertial and material strain rate effects, which constitute the damping characteristics, are modeled as predefined, rate dependent factors applied to the stiffness characteristics. The motivation for this research is to develop lumped mass models of automobiles from acceleration and barrier load data collected during frontal barrier crash testing. The underlying approach in this method is being applied in a global system identification methodology.
1990-02-01
Technical Paper
900357
W. K. Bruffell, A. J. Parkes, M. J. Wardlaw
Turbocharger manufacturers are increasingly required to produce higher boost pressure ratio compressors to satisfy the diesel engine market's demand for ever increasing specific power output. Package size constraints often prohibit the use of larger single stage or two stage installtions. This paper describes a compact and robust design of turbocharger which incorporates a small axial compressor stage mounted in front of, and close coupled to, a radial compressor of conventional design. The design and construction of this so called axial-radial turbocharger is described. Test results showing an improvement in both boost pressure ratio and usable map width are presented and discussed. Finally a method of further improving compressor map width is suggested.
1990-02-01
Technical Paper
900367
Ralph Aronberg
This paper presents a unique derivation of airborne trajectory analysis equations from the classical physics equations of uniformly accelerated motion. These trajectory analysis equations are applied to an example problem with realistic real world values. A current widely utilized equation of human trajectory analysis ignores an important cosine function in the calculation of horizontal launch velocity. It is shown that ignoring this cosine function can yield significant error in calculations. A graph is derived from published data on freefall sky diving. This graph can be referenced to adjust calculated velocities for the effects of air drag. It is shown that prior published data which has been widely utilized within the accident reconstruction profession, is inaccurate. A simple method for the application of the derived equation and data to real world problems is outlined.
1990-02-01
Technical Paper
900369
Erich S. Phillips, Tara Khatua, Garrison Kost, Robert Piziali
Many accidents involve questions regarding human visual performance. For example, drivers involved in accidents often report that they did not see what they hit, or that they saw it too late to do anything. In these cases, it is often necessary to determine if people or objects at the accident scene (pedestrians, motorcycles, other vehicles, debris, etc.) would have been visible to the reasonably alert person under conditions of a particular accident. This determination must be made with proper consideration of both inter- and intra-person variability The goal of accident reconstruction is to determine what happened in an accident, and why it happened. This process involves a thorough examination of the available evidence. More specifically, the investigator considers the physical evidence, accident reports, and statements of the involved parties and witnesses.
1990-02-01
Technical Paper
900387
Robert Roy Raine
A computer model which has previously been developed and used to model diesel engine performance has been modified to model dual fuel combustion processes. Results of the model are compared with the experimental performance of a single cylinder dual fuel engine. The original diesel model (SPICE - developed at the University of Bath) simulates the ignition delay period and the diesel combustion process using “zero-dimensional” sub-models. The development of the model to simulate dual fuel combustion has retained the same zero-dimensional approach. In the case of the dual fuel simulation, however, the combustion process models combustion of the premixed gas/air charge as well as the premixed and diffusion components of the diesel fuel combustion. The model has been verified by comparison against results from a single cylinder direct injection engine. Data are compared for engine brake power, brake thermal efficiency and ignition delay period.
1990-02-01
Technical Paper
900310
Bruce N. Greve, Sung K. Soh
To successfully model the RTM and SRIM composite molding processes, the permeability characteristics of the reinforcements must be determined. A planar gap mold apparatus was developed to measure the directional permeabilities of fiberglass reinforcements. A model of the flow in the apparatus is derived from Darcy's Law and the equation of continuity. Test results from a series of woven and nonwoven fiberglass reinforcements are shown to correlate with the Blake-Kozeny theory.
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