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Viewing 70801 to 70830 of 106966
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
900137
M. William Tripp
Detroit Edison is conducting a multi-year over-the-road evaluation of the General Motors Griffon electric van as part of the U.S. Department of Energy--Electric Vehicle Site Operations Program. This paper describes the results obtained during the period from December 1984 through June 1989. Overall vehicle and battery performance is discussed in terms of driver acceptance, acceleration, range, energy consumption and maintenance requirements.
1990-02-01
Technical Paper
900135
Peter A. Budney, Michael G. Andrew
The Advanced Battery Business Unit (ABBU) of Johnson Controls, Incorporated (JCI) is working on a contract sponsored by the United States Department of Energy (DOE) for the design and development of an advanced lead-acid battery system for electric delivery vehicles. Significant improvements in specific energy on a cell basis during the last year have positioned this technology within 6% of the contract goal of 56 Wh/kg. Currently, the majority of engineering efforts are directed towards improving the cycle life of this high performance battery. This goal is proving to be the most challenging due to the transient power nature of the SFUDS testing profile which provides a more accurate simulation of an EV duty cycle than the previously utilized constant current test regime. These efforts will culminate in the fabrication of a 180 volt, 39 kWh battery system which satisfies the performance, life, and cost goals for safe and efficient electric van propulsion.
1990-02-01
Technical Paper
900136
Malcolm J. Shemmans, Dave Sedgwick, Alina Pekarsky
Commercially viable NaS batteries are likely to become a reality by the middle of this decade, and ABB/Powerplex has already demonstrated high performance batteries for both stationary and on road applications. Utilizing the same basic cell design, the next generation batteries are already available in prototype form. They are inherently less expensive to manufacture and are capable of being fitted into a variety of vehicle platforms. Integrated vehicle control systems have also been developed which incorporate speed control, regenerative braking, battery management and on board charging. A key issue will be the fleet of test vehicles which while operating under normal commercial conditions, will be used to prove the new battery designs and associated production methods.
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
900132
Martin R. Myers
The effect of time dependent damage on elevated temperature fatigue performance has been investigated for a squeeze formed aluminum-silicon piston alloy. From the results of elevated temperature fatigue, creep and dwell tests carried out, it has been shown that creep damage has little effect at short lives but at longer lives leads to a reduction in fatigue life. It is perceived that although this damage does not directly cause the initiation of a fatigue crack, the overall resistance of the material to damage is reduced. The observed micromechanisms are related to those observed in engine tested components and the use of damage mechanisms to predict lifetimes explored. It has been shown that linear damage accumulation based on creep and fatigue mechanisms may be used to produce a first estimate of life in the materials tests.
1990-02-01
Technical Paper
900131
James E. Smith, Robert Craven Aubra O. McKisic, John C. Smith
The Scotch yoke in its various forms and inversions has received considerable attention as possible alternatives to the slider-crank for internal combustion engine use. As a recent entry, the Stiller-Smith Mechanism has shown promise as being a viable and strong option. In this study emphasis was placed on comparing the number and similarity of mechanism components and the balancing aspects of these components, implications of component and linkage motions, the severity of loading experienced by similar bearing surfaces within the engines, and some of the friction losses associated with these new motions. It was found that the Stiller-Smith Engine has significantly fewer moving parts. It was also found that journal bearings in the slider-crank engine were more severely loaded than those in the Stiller-Smith Engine. The linear reciprocating bearings in the Stiller-Smith Engine were more heavily loaded than the slider-crank piston skirts.
1990-02-01
Technical Paper
900130
Masao Adachi, Makoto Shioya, Motohisa Funabashi
This paper deals with an active suspension control problem which does not require preview information. The problem is defined as a multi -objective control problem by using a simple 2 degree-of-freedom wheel -body model. Three objectives of the control are improvement of ride, betterment of handling, and a lower power requirement of the controller. Optimal sensors, their location, and an active control algorithm are obtained as a solution to the problem by using frequency response analysis under two kinds of input forces, such as road-induced force and body inertia force. The validity of the proposed control algorithm is shown through computer simulation.
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
900144
Kazuo Araki, Yuzuru Matsuura
The sudden darting out of a pedestrian or a vehicle onto the road was used as an unexpected situation to investigate the driver's response and behavior with the driving simulator. In this emergency situation, the driving operations to avoid the pedestrian or the crossing vehicle, and the percentage of having an accident depended on the driver's driving experience. Consequently, 55% of the subject drivers operated the steering wheel to avoid the pedestrian. The drivers who applied the brakes to avoid the pedestrian were a little less than 90% among the experienced drivers, but only half of the beginners. When even both the steering and braking were used to move to the other side to avoid the pedestrian, half of the experienced drivers had accidents, and about 65% of all of them had accidents. When the beginners tried to avoid the pedestrian in various ways, almost all of them had accidents.
1990-02-01
Technical Paper
900143
R. Quinn Brackett, V.J. Pezoldt, Mark G. Sherrod, Laura Roush
The methodology and results of an evaluation of three automobile foot pedal configurations are provided. The configuration of primary interest was developed as a result of a series of empirical studies conducted to determine drivers' preferences and expectancies for pedal location. Although no significant differences among the pedal configurations were identified, the empirically developed pedal configuration is consistent with the expectancies and preferences of a large proportion of drivers.
1990-02-01
Technical Paper
900142
John Tomerlin, Mark W. Vernoy
Claims of unintended acceleration in automatic transmission cars is an industry-wide problem. Studies have indicated that in some instances the driver presses the accelerator pedal instead of the brake, and sometimes persists in this error until an accident occurs. (1) (2) Tests were designed to determine whether pedal errors affect some makes of car more than others; whether certain groups of drivers are especially prone to such errors; and whether errors occur primarily by chance or in combination with such factors as the physical characteristics of the driver, divided attention, unfamiliarity with the vehicle, etc. During static testing, 26 pedal errors were observed, 14 of them typical of unintended acceleration. One additional error was observed during field tests. It is concluded that pedal errors are more common than has been generally assumed, and that in rare instances such errors result in characteristic unintended acceleration.
1990-02-01
Technical Paper
900141
Kenji Masuda, Masami Nagata, Hirosi Kuriyama, Takeshi B. Sato
In this study, the novice driver behavior involved in traffic conflicts is investigated in order to obtain the cues of driver education program for avoiding traffic accidents. Following results are obtained that when the novice drivers encounter the oncoming vehicles, they fixate the vehicles at higher rate than the conflict objects and induce the traffic conflicts. In case of no oncoming vehicles, they also induce the conflicts because their strategies of visual search are critically concerned with the vehicle's direction of travel. They cause other traffic conflicts because it is difficult for them to maintain their vehicle on the correct lane position.
1990-02-01
Technical Paper
900140
Kenji Masuda, Masami Nagata, Hirosi Kuriyama, Takeshi B. Sato
In this study, the obstacle negotiation behavior of novice drivers is investigated under the influence of alcohol. Following results are obtained that the fixation durations for the intoxicated subjects increased in proportion to the blood alcohol concentration levels and the subjects tended to fix intensively on the specific objects for negotiation cues. All subjects exhibited the unusual saccadic movements at the intoxicated conditions.
1990-02-01
Technical Paper
900139
D. Neill, J. Bac, S. Yano, T. Xue
Abstract The U.S. has a growing dependence upon imported oil to meet transportation requirements. There are no simple alternatives, but electric vehicles (EVs) can help meet transportation needs in urban areas. Furthermore, EVs do not pollute, add to the greenhouse effect, nor cause acid rain, especially if their electrical energy is generated by safe and non-polluting renewable energy sources such as wind, solar, and ocean thermal. Hawaii's short driving distances and year-around temperatures in the range of 21-27° C (70-80° F) makes it an ideal location for optimizing electric vehicle performance. The EV program being carried out by the Hawaii Natural Energy Institute (HNEI) of the University of Hawaii, supported by the U.S. Department of Energy (USDOE), began as a demonstration program, was followed by an improvement program, and now focuses primarily on test and evaluation of battery systems.
1990-02-01
Technical Paper
900138
R. D. MacDowall
The Idaho National Engineering Laboratory (INEL) evaluates EV propulsion systems and components for the U. S. Department of Energy (DOE) Electric and Hybrid Vehicle (EHV) Program. This paper describes an INEL study which compares the exterior and interior acoustic noise levels of an electric vehicle to its internal combustion engine (ICE) counterpart base vehicle, under various operating conditions. The electric vehicle was a converted 1988 Ford Escort station wagon, retrofitted with a DC electric powertrain developed by Soleq Corporation. A comparably-equipped gasoline-fueled ICE-powered Ford Escort station wagon provided the baseline acoustic noise levels with which to compare the electric vehicle. Measurements of the interior and exterior noise levels were obtained using a Bruel and Kjaer (B&K) Type 2231 Modular Precision Sound Level Meter.
1990-02-01
Technical Paper
900114
A. Balzotti, G. M. Cornetti, F. Pidello, M. Signer, V. Scorsone
From september 1988 a fleet test started in Italy on urban buses equipped with a single ceramic monolith filter plus a by-pass and Diesel fuel burners for regeneration. The operation of the particulate trap, during the normal bus running in the city, has been assessed in three different ways: 1. Continuous control, by means of a data acquisition system purposely designed, of the main parameters affecting regeneration (i.e. time between consecutive regenerations, temperature in three selected zones in the filter during regeneration,filter loading); 2. Periodic control of smoke opacity of the bus measured, with and without the filter, under free acceleration and when bus is accelerating from 50 to 65 km/h on proving ground; 3. Particulate collection efficiency of the trap by using a dilution tunnel with the engine operated at the test bench. Information carried out from the fleet tests and additional information deriving from laboratory results were used for the system improvement.
1990-02-01
Technical Paper
900115
Frank L. Miszczak, Lucian M. Silvian
A gasket material fluid sealability test system has been developed using a fixture analogous to a bolted joint in an internal combustion engine. This system applies uniform load, simulates bolted joint rigidity, and measures leakage rate. It also measures load loss as a function of the material stress relaxation. It can be used with most liquids and gases over a broad pressure range. Novel concepts are employed to improve fluid sealability testing, such as an innovative method of applying bearing load and electronic data acquisition that assures accuracy and increases operator productivity.
1990-02-01
Technical Paper
900116
William J. Littmann
New sealing methods and materials are emerging as alternatives to traditional pre-molded gasketing in automotive applications, and the use of silicones has been prompted by the need to develop sealing materials that can withstand higher temperatures over a longer service life. Advances in sealing technology have led to innovations whose potential benefits include reduced gasket inventories, greater design flexibility and reduced manpower requirements. This paper discusses the changes which are required in traditional design techniques to ensure reliability in sealing and efficiency in manufacturing.
1990-02-01
Technical Paper
900109
K. Pattas, Z. Samaras, N. Patsatzis, C. Michalopoulou, O. Zogou, A. Stamatellos, M. Barkis
Abstract A trap oxidiser system using exhaust gas throttling as main regeneration system, coupled to a by-pass control of ceramic temperature, was installed on five experimental buses of the Athens bus fleet. Cerium Naphthenate was also used as fuel additive at different concentrations, in order to ensure safe and reliable regeneration at relatively low temperatures. The behaviour of the systems was constantly monitored through data loggers, during regular on-road operation. In order to examine the performance of all available materials, parallel tests were carried out using wall flow ceramics of different configurations and foam type ceramic monoliths. The paper presents the evaluation of the results obtained after 9 months of systems operation, with an accumulated minimum of 45,000 km of useful life per system.
1990-02-01
Technical Paper
900118
James R. Balzer, Allen M. Sohlo
Long-term exposure of typical fluorocarbon elastomers in methanol fuel mixtures indicates three very important results for the automotive fuel-system design engineer: (1) Fluorocarbon elastomers reach an equilibrium in those solutions after a short exposure, usually within 48 hours to 1 week of initial immersion, depending upon the fuel mixture and the test temperature. (2) The low-temperature flexibility (as measured by TR-10) of fluorocarbon elastomers is improved by a short immersion in these fuels. (3) “High fluorine” (greater than 66% F) fluoroelastomers are preferable over the standard grades for their superior resistance to methanol/gasoline blended fuels over an extended term.
1990-02-01
Technical Paper
900110
Alex Lawson, Kong Ha, Ian Carmichael
Progress is reported on a project to evaluate the potential of diesel particulate trap systems for retrofit application to reduce emissions from buses and trucks in the State of California. A trap system was selected for evaluation, based on availability of commercial prototypes at the time of the project. Engine dynamometer testing of this trap system is reported over advanced design bus cycles. The results showed that the system is viable for application to a bus equipped with a Detroit Diesel Corporation 6V-92TA diesel engine, producing satisfactory exhaust backpressure and emission characteristics over a 500 hour test period. Work is now proceeding on field testing of this system on a transit coach, and engine dynamometer and field testing of a similar system on a truck equipped with a Cummins NTC 350 diesel engine.
1990-02-01
Technical Paper
900112
Laslo Goldberger, Kong Ha, Jim Larocque, John Walsh, Andrew Skabowski
A diesel emission control system comprising two (2) catalyzed, monolithic ceramic exhaust filters, a diesel burner and electronic controller has been designed and installed on a 1982 GMC RTS-04 bus powered by a Detroit Diesel 6V-92TA engine. The system reduces exhaust particulates by over 80 percent and is also effective in reducing carbon monoxide and hydrocarbon emission. A minor NOx reduction was also observed. The New York City Transit Authority has operated the bus in downtown Manhattan since April, 1989. Its performance has been closely monitored and compared to a fleet of control buses running on the same route. Exhaust emission levels have been measured at regular intervals by NYCDEP to determine the emission reduction efficiencies and to track deterioration factors. Operating experience with this system is reported.
1990-02-01
Technical Paper
900125
M. Aida, T. Umaoka, T. Mitsui, Y. Ushijima
Nissan has added ball bearings to its “High-flow Ceramic Turbocharger”(1) (introduced in 1987) to improve acceleration response by reducing friction loss. The following programs were carried out in applying ball bearings to the turbocharger: Optimum bearing size and material were selected to assure long life; lubrication techniques were employed to achieve compatibility between acceleration response and durability; a thrust support system was designed to assure that the ball bearings endure thrust load which varies in direction and magnitude during engine operation; and the squeeze film damper was optimized to keep the turbocharger silent. These innovations have resulted in a practical ball-bearing turbocharger, which has been installed in Nissan's most recent Skyline model(released in May 1989). This is the first time a ball-bearing turbocharger has been applied to a passenger car.
1990-02-01
Technical Paper
900127
R. Wade Allen, Henry T. Szostak, Theodore J. Rosenthal, David H. Klyde
This paper considers ground vehicle lateral/directional stability which is of primary concern in traffic safety. Lateral/directional dynamics involve yawing, rolling and lateral acceleration motions, and stability concerns include spinout and rollover. Lateral/directional dynamics are dominated by tire force response which depends on horizontal slip, camber angle and normal load. Vehicle limit maneuvering conditions can lead to tire force responses that result in vehicle spinout and rollover. This paper describes accident analysis, vehicle testing and computer simulation analysis designed to give insight into basic vehicle design variables that contribute to stability problems. Field test procedures and results for three vehicles are described. The field test results are used to validate a simulation model which is then analyzed under severe maneuvering conditions to shed light on dynamic stability issues.
1990-02-01
Technical Paper
900119
Kyle T. Roberts
Pre-molded silicone gaskets have proven to be extremely successful for sealing engine components such as rocker covers and oil pans, but methods are being sought to reduce the cost of using silicones to seal these and other components without compromising the quality achieved with pre-molded gaskets. One method, known as cured-in-place gasketing (CIPG), involves dispensing a liquid silicone rubber (LSR) directly onto a component and allowing the bead to cure to form a gasket. The purpose of this paper is to outline the process through which Dow Corning systems enginneers design CIPG sealing systems.
1990-02-01
Technical Paper
900123
Yukio Ogita, Yasuo Ido, Masaaki Sakamoto
A sintered aluminum-lead alloy of the bimetal type was manufactured in Japan (1977), and has been widely used in main and crankpin bearings for automobile engines. However, the recent trend of automobile engines toward high power output, light-weight and compact construction increases the bearing load. As a result, the margin of fatigue strength of the conventional sintered aluminum-lead alloy has been diminishing. In this paper, a new method of manufacturing bearing material by the hot extrusion process is reported. The new method makes it possible to produce the optimum lead grain distribution and strong adhesion between powder particles. The new manufacturing method produces the aluminum-lead bearing material which has 30% or more increase in fatigue strength over the conventional sintered aluminum-lead bearing material.
1990-02-01
Technical Paper
900121
Dennis E. Hull, Robert E. Eggers, Werner M. Grootaert, Robert E. Kolb
Specification testing has shown FKM fluoroelastomers are significantly affected by newer engine oils, transmission fluids and extreme pressure gear lubricants. A new fluoroelastomer and cure system has been developed which provides better chemical resistance vis-a-vis FKM fluoroelastomers to these fluids. The unique backbone structure of propylene, tetrafluoroethylene and a specific third monomer is different from FKM fluoroelastomers and together with a proprietary cure system accounts for the improved chemical resistance. This new elastomer is available from 3M and it will be referred to as TPT in this paper.
1990-02-01
Technical Paper
900124
Masaaki Sakamoto, Yukio Ogita, Yoshiaki Sato, Tadashi Tanaka
The recent trend toward the compact and light-weight construction of diesel engines with high power output has been imposing higher requirements of fatigue strength and antiseizure characteristics on bearings. In order to meet these requirements, the authors developed a new bearing alloy of higher fatigue strength for use in heavy load engines, through the analysis of the Al-Zn-Si alloy which has high corrosion resistance. Experimental results of this new alloy to study its physical properties and bearing performances indicate that it can be applied to bearings in diesel engines which operate in harsh conditions.