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Viewing 151 to 180 of 36595
1990-02-01
Technical Paper
900829
Jim Gould
This paper presents a total automation scheme for the manufacturing of headliners, optimizing quality, while maintaining minimum amount of labor for low cost manufacturing. The system approaches a “lights out” concept of manufacturing. The system consists of automated manufacturing lines providing flexible manufacturing, control, and diagnostics, SPC, process status and tracking with each cell operating as a separate manufacturing entity monitored by a communication network. Cell controllers provide control coordination, data collection, and downloading of component programs. An automated guided vehicle (AGV) material handling system provides transport and inventory control of materials. A factory management computer system provides dynamic scheduling, inventory control, SPC/SQC data collection and production analysis.
1990-02-01
Technical Paper
900831
Mohamed E. M. El-Sayed
Abstract This paper presents a method for studying the effect of frequency requirements on the optimum design of automotive structures. Performing such studies can lead to better designs, by helping the designer understand the nature of the design space and the effect of the frequency requirements on the optimum design. To demonstrate the methodology and the effect of the frequency requirements a case study for the optimum design of an automotive structure is considered.
1990-02-01
Technical Paper
900819
Katsutoshi Horinouchi, Takashi Yonekawa, Shingo Ito, Hiroshi Kobayashi
With the progress of super computers in recent years, a number of studies on “Computational Fluid Dynamics” (CFD) have been carried out, and various schemes for Navier-Stokes equations have been presented. Similar methods have also been applied to automotive engineering - aerodynamics, for exampre - in order to determine flow phenomena. In this paper, the application of numerical simulations to the flow cavitation that occurs in some part of orifices in the vehicle hydraulic system, will be discussed. Authors have developed a CFD program for the clarification of flow phenomena in such orifices. Using the relationship between calculated results and measured results of noise levels in such orifices, a new method for estimation of the occurrence of flow cavitation has also been developed. As a result, a new orifice configuration capable of preventing the cavitation has been designed.
1990-02-01
Technical Paper
900817
Brian W. Deutschel, Richard B. Katnik, Mohan Bijlani, Ravi Cherukuri
In the initial design stages of a vehicle, one desires to analyze and improve the response of the vehicle when sitting at idle or when travelling down various roads. One can perform such analyses and improvements to an FEM model using NASTRAN. However, a faster and easier method has been developed into a postprocessor to NASTRAN called FASTAR. Initially FASTAR was created to supplement NASTRAN by providing interactive graphics modal animation, structural modifications, and sinusoidal frequency response using a reduced modal space. With greater emphasis on vehicle analysis, FASTAR has been modified to process much more complicated loads generated by engines and road profiles. To simplify user input, engine data and road data have been integrated into two comprehensive data bases. As a result, one can now very easily choose in FASTAR specific engines and quickly compute the engine induced vehicle response.
1990-02-01
Technical Paper
900824
Hiroyuki Kano, Masaaki Kato, Terutada Kojima, Makoto Katagiri
The purpose of this paper is to discuss spray control of nozzle for heavy duty diesel engines. This paper will focus on fuel flow analysis of nozzle, key component of FIE (Fuel Injection Equipment). The optimum designed nozzle controls fuel flow and improves flow efficiency. FIE is required to produce higher injection pressure which creates better atomization and higher utilization of air. But the higher injection pressure results in increased pump driving torque, larger pump size and higher cost. To improve the fuel flow characteristic of nozzle, we analyzed it and developed a theoretical analysis method with computer model simulation to the optimum design nozzle. We also confirmed its effect by experiments.
1990-02-01
Technical Paper
900818
Sridhar Kota, James G. Boerger
Abstract The pulleys employed in automotive accessory drive systems very often consist of a two piece assembly; a multitude of fastening techniques are used in completing the assembly. There are numerous assembly methods and a variety of distinct pulley configurations dictated by the various automobile manufacturers in accordance with individual accessory drive needs. An expert system is being developed to evaluate the merit of multiple assembly alternatives for a specific pulley application. The expert system provides a consistent evaluation tool for assembly alternatives, balancing the influence of product cost, strength and quality considerations. The knowledge-based system is implemented in an expert system shell called AGNESS (A Generalized Network-based Expert System Shell). The expert system judges the acceptability of various pulley assembly techniques, assigning a high “merit value” to the better designs and proportionately lower values to less desirable designs.
1990-02-01
Technical Paper
900823
D. H. Gibson, P. J. Dionne, A. K. Singhal
Abstract This paper describes a numerical model developed to predict the elastohydrodynamic (coupled solid-fluid) response of unit injector fuel systems. These systems consist of a concentric barrel and plunger with a small annular clearance. During operation (axial movement of the plunger), highly non-uniform pressure and clearance fields are developed which are strongly coupled with each other. The model simultaneously solves for the transient response of the fluid film pressure distribution and three different structural deformation components in a two-dimensional (axial-circumferential) domain. These structural components are the transverse bending of the plunger, radial expansion of the barrel, and radial growth of the plunger from a Poisson effect. The fluid film pressure distribution is governed by the transient Reynold's equation (i.e. lubrication theory) and the structural deformation components are governed by linear elastic theory.
1990-02-01
Technical Paper
900816
Jong S. Kim, David Kotkoff, Jan Cernosek
Abstract In the early prototype of CELECT (Cummins' electronically controlled injector), the fatigue cracks were initiated in the injector body at the intersection of a drilled hole of 2.5 mm diameter and a hemispherical valve pocket. It was believed that the high stress concentration at the intersection produced by over 139 MPa fuel pressure caused the fatigue failure. A three dimensional finite element model was built using the ANSYS program to calculate the stress concentration factor for the new, improved design. A three dimensional photoelastic model was built as validation of the finite element analysis. The photoelastic analysis using the stress freezing method showed good agreement with the finite element analysis. The analyses showed that the stress concentration factor of the intersection without a chamfer was 1.5 as compared with 1.3 stress concentration factor with a chamfer. Engine tests further demonstrated the validity of the proposed design.
1990-02-01
Technical Paper
900820
S. Aϊta, A. Tabbal, G. Munck, K. Fujiwara, H. Hongoh, E. Tamura, S. Obana
This paper describes a CAD/CAE approach for the numerical simulation of port-valve-cylinder flow in reciprocating engines. This approach complements the classical experimental approach, using steady state and transient measurements, and it can replaces experiments at the design stage. Computer software and hardware environment are discussed, including aspects concerning solid body modeling, mesh generation, CFD calculation, CPU requirements and results analysis. The simulation approach is assessed and validated through comparison with axisymmetric laboratory test results and actual engine configuration test results from MAZDA. The paper focuses on steady state analysis with open valve, and discusses the reproduction, by simulation, of flow features in the port- valve region, and their interaction with the flow on the entire port-valve-cylinder path.
1990-02-01
Technical Paper
900806
T. G. Kinisky, D. A. McKenzie
Automotive water pump seals which have failed prematurely during in-service use have been characterized using a variety of analytical methods. Nearly one hundred failed seals collected over the past several years from local automotive dealerships, major automotive manufacturers, coolant related fleet tests, and pump seal manufacturers have been examined as part of this study. This has enabled us to determine the chemical composition and morphology of surface deposits on failed seals and classify their failure mode. The main failure mode found for domestic in-service automobiles is filming, a term used to describe a failure type in which deposits form between the sealing surfaces resulting in a leak path. This paper reports on the composition, morphology and possible causes of in-service filming failures. In addition, the results of this study will be contrasted with those reported in other studies which found film transfer as the main type of failure.
1990-02-01
Technical Paper
900796
I. J. McGregor, A. D. Seeds, D. Nardini
As part of the development of Aluminum Structured Vehicle Technology (ASVT), significant advances have been made in the design of impact energy absorbing members for automobiles. This paper compares the performance of aluminum and steel impact members, and discusses the influence of the material properties of aluminum on subsequent impact member performance. Methods for designing aluminum impact members for stability, collapse initiation and subsequent collapse performance are presented. This includes both analytical and finite element modelling.
1990-02-01
Technical Paper
900797
M. J. Bull, A. R. Carr, P. Payne, C. Suffell
A Knowledge Based CAD System has been developed to investigate various aspects of press tool design, and to assist with the introduction of stamped aluminum into automobile structures. Knowledge based design “rules” which have been derived directly from: material properties, FEM parametric studies, deformation mechanics, simple heuristics, and various geometric features, are demonstrated.
1990-02-01
Technical Paper
900798
B. Hector, W. Heiss
The integrated three-point safety belt for the driver and co-driver seat of the new Mercedes-Benz Roadster is the first of its kind to be utilized in a production car. The shoulder belt, including the automatic spool and belt preloading device, is incorporated in the seat back rest. This concept allows an adjustment of the belt geometry to nearly any passenger size, particularly in sports cars, which have no full-size middle post, and thus makes a major contribution to passive safety. Because of new magnesium alloys and improved casting techniques, it is now possible to produce the frame elements of the seat of high ductility magnesium pressure-die-casting, and thus ideally combine the requirements for mechanical strength, economy and production techniques.
1990-02-01
Technical Paper
900800
J. G. Smyth, R. G. Kenny, G. P. Blair
The application of in-cylinder multi-dimensional modelling to the scavenging process within the cylinder of a two-stroke cycle engine requires a prior knowledge of the flow entering that cylinder. Without this information, assumptions must be made which limit the accuracy of the theoretical simulation. This paper describes laser doppler anemometry measurements of transfer port efflux flow for a two-port loop scavenged test cylinder motored at 200 rev/min. The cylinder was externally blown to ensure scavenge flow into the cylinder over the entire transfer port open period. The test results indicate that the flow does not enter the cylinder in the port design direction, but varies as a function of port height during both port opening and closing. Comparison of motoring results with those obtained under steady flow testing of the same cylinder, shows adequate correlation, thereby justifying the use of steady flow information for dynamic simulation.
1990-02-01
Technical Paper
900152
Yoshihiro Nomura, Katsuyuki Ohsawa, Tomoji Ishiguro, Masahiko Nakada
A laboratory test simulator has been developed to analyze the intake-valve deposit formation mechanism. The characteristics of the deposits formed with the simulator were compared with those of the real engine deposits. This comparison verified that the simulator deposits ILLEGIBLE nearly equal to those of engines. The influence of each parameter such as valve temperature, oil or gasoline quality was tested individually using this simulator. The intake valve temperature influenced the location and quantity of the deposits. The deposit formation significant in the temperature range of about 0-350 °C. The high-boiling components of oil ILLEGIBLE increased the deposits. The increase oxidation products and the decrease of antioxidants in used oil caused a significant increase of deposits. The commercial premium gasoline in Japan containing practical detergents ILLEGIBLE down and decreased the deposits. Another premium gasoline affected the oil quality, in increasing the deposits.
1990-02-01
Technical Paper
900156
James McGuire, Harry Stefanou
: Mold filling analyses for mold design, and design of experiments, either classical or as taught by Taguchi are revolutionizing the way we are doing business. In this paper we use the DOE technique to evaluate the effects of 12 variables on the predictions of mold filling analyses. These effects are for our purposes the errors caused in prediction by inaccuracies in parameter measurement. The efficient use of the experimenter's time is guided by the results of these studies.
1990-02-01
Technical Paper
900158
William T. Zeddell, Joseph C. Palermo
For the American Automotive Industry to remain competitive, continued technological advances through application modelling and optimization are necessary. Ford Motor Company, in conjunction with The Durez Division of Occidental Chemical Corporation and Altair Engineering, applied this strategy to a phenolic power steering pulley which has been in production since 1985. An optimized Finite Element Analysis model was developed resulting in a primary phenolic mass reduction of over 30% while still meeting the performance requirements. There were also a number of secondary system effects that evolved from the model process.
1990-02-01
Technical Paper
900159
G. R. Henry
Abstract Future directions in finite-element modeling are examined, with emphasis on design-optimization techniques. A powerful and intuitive new method, Geometric Element Modeling™ is described, based on well-understood, proven extensions of finite-element methods to higher-order analysis. Among the features offered by GEM are automatic analysis, converged to the limit specified by the user, elements with curved edges and surfaces, feature-based analysis, and a powerful set of optimization tools.
1990-02-01
Technical Paper
900160
David Ganoung
Many automotive engineers do not associate drive-by-wire control with any improvement whatsoever in fuel economy. Nevertheless, computer simulations have now been based on stationary engine dynamometer testing of a recalibrated production engine, and these simulations of actual driving strongly suggest that fuel economy improvements in the area of 10% will result from utilizing a drive-by-wire approach which employs several novel features. Notable among these features are a dual wide-open-throttle engine calibration originated for use with continuously variable transmissions and a transmission shift control strategy which relies on electronically stored engine performance data in lieu of any form of transmission shift map.
1990-02-01
Technical Paper
900162
Jan Takemura, Daisake Sanbuyashi, Hiromitsu Ando
Three zone mixture preparation model, assuming that fuel and air are distributed in three separate zones, fuel air and mixture zone, was proposed. Air Utilization Efficiency derived from the model was used to evaluate the mixing nonuniformity. Effect of the large scale nonisotropic turbulence downstream of the dimple or edge in the intake port of MPI engine on the convective mass transfer from fuel film was clarified by the proposed nondimensional index, Local Sherwood Number. It was found that when the fuel is injected toward the wall where large scale turbulence exists, almost all of the fuel is seeded in the air passing the region at the beginning of the intake process, resulting in the time-resolved nonuniformity of the mixture strength at the intake valve. Using the Air Utilization Efficiency, it was elucidated that time-resolved mixing nonuniformity at intake valves induces spatially nonuniform fuel/air distribution in the cylinder.
1990-02-01
Technical Paper
900166
Terranee C. Wagner, Richard W. Anderson
A super-microcomputer is utilized in an engine-dynamometer facility to create a comprehensive engine evaluation system. A unique feature of this system is the combination of experimental and modelling activities in evaluating engine designs. The system acquires engine operating conditions, emissions, and dynamic cylinder and manifold pressures via the data acquisition interface. After acquisition, the computer is also capable of providing engine model predictions from either an empirical model or a zero-dimensional thermodynamic model. The data gathering process is speed limited by the settling time of the engine-dynamometer system. The acquisition and modelling procedures are controlled by an internally developed, menu driven, software package. Features of the system include commercial relational database software for rapid storage and retrieval of acquired data and a high resolution graphics monitor for immediate display of analyzed pressure data.
1990-02-01
Technical Paper
900134
A. S. H. Lowe
The damage occurring on the coolant side of cylinder liners due to cavitation erosion is of increasing concern to today's engine manufacturers striving for increased specific power and reduced weight. Identification of a cavitation problem does not usually occur until failures are reported in service. This is due to the difficulty in predicting cavitation at the design stage and in detecting damage in a running prototype. Therefore a new method for the analysis of cavitation erosion damage in cylinder liners has been developed. The technique, which is based on the use of the finite element method, provides a tool for the engineer to investigate the effects of design changes on cavitation intensity, without the direct need for expensive test work. The sole source of liner excitation is assumed to be from piston slap. Following calculation and application of the piston impact energy, the transient response of the liner is predicted.
1990-02-01
Technical Paper
900145
Trevor J. Brown
Abstract In June 1987, U-Mold Co. Ltd, a Division of Ube Industries, started commercial production of Aluminum Wheels using a new “Gas Free/Squeeze Casting Process”. The new process has produced intricately designed wheels with physical properties approaching those of a forging. The absence of gas and shrinkage porosity has virtually eliminated the leakage problem associated with other wheel castings. Because of the fine grain structure and the absence of porosity in the castings, appearance quality of the fine machined surfaces has been greatly improved and some painting defects eliminated.
1990-02-01
Technical Paper
900147
H. M. Karandikar, Willi Fuchs
A prototype computer-based system, called FLIPS, for predicting the fatigue life of wheels has been developed. The system utilizes linear finite element structural analysis results and is comprised of a CAD package, a finite element analysis program, and a fatigue life computation program. Presently it simulates the results of the rotating bending test very successfully. With this system it is possible to obtain a lower bound on the fatigue life of wheels and to get a very good idea of the critical areas of the wheel. We believe that using this system the development time for new wheels can be considerably shortened. Special effort was required to determine the correct boundary conditions for the finite element models. An original procedure was developed for computing the stress amplitudes and mean stresses in complex structures and for using this information for predicting the fatigue life using the local strain approach, after applying a correction to account for linear analysis.
1990-02-01
Technical Paper
900187
Uwe W. Schaub, M. Eugene Olson, S. Raimondo
A critical assessment is made of tunnel wall interference corrections, indicated testing limits, and the data correlations for yawed truck models inside a solid-wall test section, using a modified pressure-signature method. Two models, a full-size tractor-trailer and a similar half-scale model, were tested in the 9 x 9 meter wind tunnel of the National Research Council of Canada (NRCC). Both models were yawed through ±14° with full length and truncated trailer bodies for the purpose of determining wind-averaged drag and exploring the real aerodynamic testing limits due to tunnel interference. The correction method employed an algorithm to perform an iterative solution to determine the strengths of potential sources, sinks, and horseshoe vortices for given inputs (measured ceiling pressures, side force, yaw and roll moments, as well as dimensional data). The output comprised corrections to tunnel dynamic pressure and yaw angle, and a horizontal buoyancy effect.
1990-02-01
Technical Paper
900188
Lakhi N. Goenka
: This paper presents a numerical model consisting of a two-dimensional, inviscid, stream-function vorticity code with a slotted-wall boundary condition. The model can be used to predict vehicle pressure-simulation accuracy in a slotted-wall automotive wind tunnel for a range of test section configurations. The vehicle and its wake were modeled as a combination of a doublet and a wake source, and the slotted-wall boundary condition was calibrated using published experimental data. Despite its inherent approximations, this model produces results that agree remarkably well with magnitudes and trends observed in published experimental data. This model was used to determine the length needed for a slotted-wall test section containing both a turntable and a dynamometer for aerodynamic as well as thermodynamic testing capability. Tests were conducted on a 1/12-scale slotted-wall test section to confirm the test section length predicted by the numerical model.
1990-02-01
Technical Paper
900192
Anthony J. Yanik
It is doubtful whether a vehicle designed specifically as an “old person's car” could ever achieve success inasmuch as the culture in which we exist assigns only the most negative of attributes to such characterizations. Nevertheless, there are numerous vehicle technologies that are emerging or under longer range development that may be of special benefit to the elderly. This paper will discuss these technologies, and explain how they might help offset some of the declines in vision and cognition that mature drivers experience through aging. Concern over the mature driver and his or her capabilities to drive safely have received increased emphasis within the private and public sectors over the past several years. While such a concern is appropriate, it would not exist today if automobile manufacturers over the years had failed to develop the various power assist technologies that have enabled adults to continue driving well into advanced age.
1990-02-01
Technical Paper
900169
J. E. Henry, E. H. Kemp, J. K. Dunn, H. E. Jenkins
Abstract This paper describes Consolidated Diesel Corporation's approach to optimizing Production Engine Test Deployment utilizing Statistical Methods to treat daily production as populations rather than the more traditional One Test-One Decision-Each-Time. The transformation in thinking from one engine-one decision regarding accept/adjust/reject to applying the classic rules of Statistical Quality Control (SQC) & Statistical Process Control (SPC) began with a cross functional workgroup conducting a Taguchi L12 Orthogonal Array Design of Experiment. Results of that testing provided the workgroup insight into mapping the per cent tolerance consumed by fuel system settings, engine timing, fuel viscosity, and instrumentation. Substantial improvements in first time pass rate, productivity thruput, and inventory turns have been documented.
1990-02-01
Technical Paper
900176
Michael Y. Young, David A. Penz
This paper describes the design of a new turbocharger gas stand facility and shows how the design addresses requirements for increased productivity, measurement accuracy, economy, and operational safety. Based on this design, an automated turbocharger research and development test facility has been constructed. The test facility incorporates the latest technology in mechanical components, instrumentation, control systems and data acquisition hardware and software.
1990-02-01
Technical Paper
900175
R. H. Thring
Some advantages may be gained from permitting variation in diesel engines of parameters that are normally fixed, such as mechanical compression ratio. Such an engine could be described as a flexible engine. This paper describes the results of computer modeling work carried out on a hypothetical engine that could be in production by the year 2000 for heavy-duty truck application. The engine--a six-cylinder, in-line, turbocharged, four-stroke engine with air-to-air aftercooling-was modeled using the TRANSENG computer program. It had a swept volume of 8.5 liters and produced 224 kW (300 hp) at 2000 rpm. Modeling work was carried out with a variable geometry compressor, a low-speed optimized compressor, variable compression ratio, and variable valve timing using the Miller cycle. The variable geometry compressor allowed an increase in BMEP of 5 percent and a decrease in fuel consumption of the same amount at rated power.
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