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Viewing 181 to 210 of 36595
1990-02-01
Technical Paper
900178
Samuel Romano, L. Dean Price
Electric propulsion has long been considered as a replacement system for the internal combustion engine to reduce air and noise pollution and dependence on imported oil. This objective has been difficult to achieve with battery powered vehicles. Limited energy storage recharge time does not allow the EV to provide the long range travel that the ICE offers through rapid refueling. The fuel cell powered electric vehicle can overcome this handicap. It is fueled with liquid methanol which can be rapidly replenished. Introducing the fuel cell as a power source for transportation requires selection of the right application and an engineering approach to the integration of vehicle and power system.
1990-02-01
Technical Paper
900177
L. Roy Leembruggen
: Only now do thinkers realise that transport energy and environmental problems will be solved by eliminating the combustion process from commuting vehicles. Electric-drive permits this, and by matching the vehicle with its real mission, present batteries and related technology enable volume manufacture now of electric cars and vans. Twenty years of systematic research, development and testing, and a “purpose-built” rather than “evolutionary” philosophy have optimised TOWNOBILE vehicles to eliminate the ICV-EV weight difference, bring the price difference within 25% and permit viable production in relatively small quantities for such opportunities as the Los Angeles Electric Vehicle Initiative.
1990-02-01
Technical Paper
900081
Shiro Ikuta, Yosihiro Sasaki, Kaoru Tanaka, Michitoshi Takagi, Ryutaro Himeno
1. ABSTRACT The main function of automobile heat exchangers is to transfer residual heat from the engine to the open air so as to keep running the engine at its best condition. In order to efficiently transport heat from the heat exchanger to the air, extended surfaces (e.q., fins) are usually provided over the outer surface of the water tube in the heat exchanger. Moreover, many bent out plate louvers are manufactured on the fin safaces. In order to obtain higher rate of heat transmission in a more compact heat exchanger, many experimental and analytical studies have been carried out up to the present. However, there are many difficult problems to be resolved so far in finding the obtimum louver profile because of the complexity of air flow around small-scale louver assemblies.
1990-02-01
Technical Paper
900084
Kenji Tojo, Kunihiko Takao, Masaru Ito, Isao Hayase, Yukio Takahashi
To meet the demand for improved comfort, driveability and fuel economy standards, a continuously variable displacement compressor has been developed. The compressor has a unique compression mechanism, which automatically changes displacement volume to exactly match vehicle air conditioning requirements. The compressor controls the pressure differential between the crankcase and the cylinder inlet and uses the pistons as actuators to change compressor displacement. This paper outlines an analytical model for evaluating the dynamic behaviour of the variable displacement compression mechanism. The model gives detailed geometric and kinematic information regarding each element. It also calculates gas torque fluctuation, nutating motion of the wobble plate, constraint forces of each pair of machine elements and unbalanced forces of inertia. It calculates the pressure differential between the crankcase pressure and the cylinder inlet pressure required for displacement control.
1990-02-01
Technical Paper
900086
Kiyohira Aoki, Yuji Hanaoka, Masayuki Hara
Numerical analysis of flow around the front end and in the engine compartment of FWD vehicles in three-dimension is presented. Finite - Volume Method is used for numerical integration of Navier-Stokes equations, incorporating k-ε model for turbulence. This method proved to be effective tool, showing good agreement of volume flow rate through radiator with experiments. Application of this method from the early stage of vehicle development contributed to significant saving of development term.
1990-02-01
Technical Paper
900078
Deborah S. Rousseau, Raymond F. Kolberg, Zenon Hotra
Abstract The increased demands of today's complex automotive connector designs have led to the development of engineering structural analysis tools which address the performance issues of the connector's snap-finger. In designs where hand calculations were once considered the norm in evaluating snap-finger performance, the analysis tools have evolved into the use of finite element techniques which address the high nonlinearity issues of snap-finger disassembly and terminal pull out strength. The structural analysis approaches developed investigate the connector snap-finger performance in reinforced engineering thermoplastics while incorporating the effects of geometric and material nonlinearity in the results. The techniques developed allow for the evaluation of snap-finger performance of prospective connector designs before expensive tooling and prototyping is initiated, providing the benefits of limited tool rework and decreased product development time.
1990-02-01
Technical Paper
900080
Yuichi Shibata, Seishin Hosaka, Katsuro Fujitani, Ryutaro Himeno
The acceleration performance of a car equipped with a turbocharged, intercooled engine is affected by the volume of cooling air that flows through the core of the intercooler. Additionally, the volume of cooling air entering the intercooler is influenced by the configuration of the air intake provided in the exterior design. Therefore, in planning a new model it is very important to be able to predict acceleration performance, at an early stage of the vehicle development process, in relation to vehicle styling and engine specifications. The procedures employed so far to predict the volume of air flowing through the intercooler have included two-dimensional finite-difference methods and a panel method. However, because of their simple nature, none of these approaches has provided sufficiently accurate results. This paper presents a new numerical analysis method that has been developed to overcome this problem.
1990-02-01
Technical Paper
900091
Roy A. Palasek, Stephen C. Goodall
In August, 1988, Monsanto Chemical Company contracted the services of J. D. Power and Associates to obtain market research of consumers perceptions of quality of vehicle interiors and of the plastics used within. Focus Group methodology was utilized. Results obtained were of a qualitative nature only. Clear-cut, strong impressions of “quality” of most interior applications were obtained. These opinions were distilled down to identified generalized consumer quality concerns: 1) styling/design, 2) mastering, 3) execution of design, and 4) resultant mass production quality. In each of these areas, selection and use of plastic materials was a significant contributor to a positive or negative perception of quality.
1990-02-01
Technical Paper
900092
Takashi Nishiyama, Shuichi Yokota, Michiaki Izawa, Masao Minami, Noboru Hagiwara
1. ABSTRACT As for recent market needs, there is an increasing demand for the total coordination of the vehicles interior trims, the enhancement of adaptability for freer designs, soft touch and weight reduction. In order to meet these demands, we have developed a door trim reflecting this new concept. This door trim is manufactured by foaming rigid polyurethane foam as the core material after the double slush skin (1st layer: PVC, 2nd layer: PVC foam) and the glass mat are set together in the foaming mold. Employment of double slushed skin allows an improvement in flexibility of design, softer materials to be manufactured and further coordination of color, gloss and grain pattern with those of instrument pad. In addition, we have succeeded in reducing the weight by using glass mat reinforced rigid polyurethane foam.
1990-02-01
Technical Paper
900085
Tadashi Mizuno, Koichiro Kikuchi
For the combination of radiator and fan working under high flow resistance of radiator system, “the Axial Flow Fan with Diagonal Flow Hub” has been developed. A study of the useful ranges of the cone angle of diagonal hub and depth of fan, two dimensionless shape parameters are presented and confirmed through experiments. With One Dimensional Theory and calculation of meridional streamlines by the Stream Curvature Method, diagonal flow effect, especially near the hub, has been discussed. From the performance tests and flow visualization method by tufts concerning typical combinations of the values of fan depth and cone angle, the better performance and favorable stream conditions are clarified. On the standard shape of diagonal flow hub putting the results of performance tests into the curves of two shape parameters, the optimum shape regions are presented.
1990-02-01
Technical Paper
900067
Chuck Beyer, David Wright, Rob Klausmeier, Williams Clemmens
The oxygen sensor is a critical component of modern vehicle emission control systems. Oxygen sensor failure can result in high vehicle emissions. Many states have inspection and maintenance (I/M) programs to detect and correct high emitting vehicles, but most programs have a repair cost limit. A study of oxygen sensor designs, prices, and applications was conducted. The study showed that many oxygen sensors are constructionally and functionally the same, but their retail prices vary greatly. The high retail price of some oxygen sensors often exceeds the I/M repair cost limit, therefore high emitting vehicles with failed oxygen sensors are not always repaired.
1990-02-01
Technical Paper
900072
Barbara A. Fenton, Dirk M. Baars
In an effort to eliminate asbestos reinforcements in their automotive auxiliary motors, Rogers Corporation and Delco Products (Div. of GM) worked together to develop a non-asbestos glass reinforced phenolic substitute. Upon initial process start-up, Delco Products suffered from high incidences of commutator cracking as the parts were demolded. While making the usual process adjustments temporarily alleviated the problem, the cracking reoccurred in an unpredictable fashion. In an effort to permanently eliminate the high incidences of cracking, a three-way joint designed experiment was carried out between Delco Products, Rogers Corporation, and Borden Industrial Resins. Four significant factors were identified which led to new raw material specifications, adjustments in molding conditions, and a permanent decrease in the incidences of cracking from as high as 60% down to 0.5%.
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
900113
Jun Kitagawa, Toshihiko Hijikata, Mikio Makino
Ceramic honeycomb wall flow diesel particulate filters (DPF) have been investigated for use in exhaust gas control of diesel vehicles. However, before they can be used, prevention of thermal shock failure during combustion regeneration is necessary. Studies were conducted on thermal shock failures on 9-inch diameter large volume DPF during regeneration by finite element analyses (FEA). These studies reveal that, within safe limits, maximum thermal stress is almost constant even at different gas flow rates and oxygen concentrations. Regeneration tests were also conducted on large volume DPF of several materials having different pore size distributions. FEA thermal stress was compared with mechanical strength of the material at safe levels.
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
900129
Jeff S. Loeb, Dennis A. Guenther, Hung-Hsu Fred Chen, John R. Ellis
Abstract This paper describes an experimental program of tire research used to quantify the concept of the “relaxation length” of the fully rolling, steered tire. Two methods of developing lateral force are compared for the general car with the result that a first-order differential equation is obtained from which the change is lateral force with time, or distance, as the steer angle variation is computed.
1990-02-01
Technical Paper
900128
Gary J. Heydinger, W. Riley Garrott, Jeffrey P. Chrstos, Dennis A. Guenther
This paper presents a methodology for validating vehicle stability and control computer simulations. Validation is defined as showing that, within some specified operating range of the vehicle, a simulation's predictions of a vehicle's responses agree with the actual measured vehicle's responses to within some specified level of accuracy. The method uses repeated experimental runs at each test condition to generate sufficient data for statistical analyses. The acquisition and reduction of experimental data, and the processing path for simulation data, are described. The usefulness of time domain validation for steady state and slowly varying transients is discussed. The importance of frequency domain validation for thoroughly validating a simulation is shown. Both qualitative and quantitative methods for the comparison of the simulation predictions with the actual test measurements are developed.
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
900102
Terry D. Day, Randall L. Hargens
The accuracy of the SMAC computer program was evaluated in terms of its ability to predict the correct paths and damage profiles for vehicles involved in a crash. A comparison of the results from SMAC and EDSMAC were presented along with measured results from twelve staged collisions. Statistical analysis of those results revealed the average path error was 25 to 29 percent and the average damage profile error was 109 to 287 percent. A procedure was presented for improving the match between simulated and measured paths. After using this procedure, the average path error was reduced to -2 to 7 percent and the average damage profile error was 54 to 186 percent. CDC predictions were very good. Damage profile errors, which did not reduce the program's overall effectiveness, were the result of the way the program computes inter-vehicle forces, leading to a recommendation that the algorithm be reformulated to include an initial force coefficient.
1990-02-01
Technical Paper
900099
Albert G. Fonda
Past, current, and proposed formulations which express the crush energy of irregular and oblique collision deformations, based on tests with regular and normal deformations, are reviewed in the context of single-event (forensic) reconstruction. Improvements in energy and delta-V valuation, beyond that needed for statistical studies of multiple events, are possible and available.
1990-02-01
Technical Paper
900042
Shoji Suzuki, Hank Hamazaki
While the market acceptance and the demand for car CD players is growing, the CD Changer has very high potential for automotive use because of its easy handling by the driver. This paper describes the analysis of the market, the creation of the product concept, the technical themes for the development, and the result. As technical themes, we focused on miniaturization of the mechanism and vibration performance.
1990-02-01
Technical Paper
900032
Toshihiko Osumi, Koji Onishi, Hidetoshi Nobumoto, Kazutoyo Watanabe, Junichi Funamoto
The power output performance of the rotary engine can be improved when the dynamic effects of intake and exhaust systems are utilized. Previous studies have shown that one-dimensional gas exchange process simulations are effective in developing these systems. However, this type of simulation is difficult to apply to the peripheral port type rotary engine because of the simultaneous gas exchange between one port and two combustion chambers. To account for this, a boundary model connecting the pipe and plenum chambers was developed. This study shows the validity of this new model and the successful application of the simulation to the engine.
1990-02-01
Technical Paper
900041
Clive Grinyer, Martin Darbyshire
Abstract In recent years the car radio has evolved from a simple mechanically operated product to a high quality and sophisticated piece of audio equipment. The use of technology has provided the user with many new features, and to help provide designs which satisfy the requirements of customers for both higher acoustic performance and simpler, familiar methods of operation, industrial designers have been used to style and configure in car sound equipment. This paper looks at some examples of design solutions to current radio products, and looks at how design can be used to integrate technical developments with changing user tastes and requirements.
1990-02-01
Technical Paper
900238
Naoki Tomisawa, Derek L. Davis
Through the rapid evolution of microcomputer capability in the field of automotive electronic fuel injection, a system has recently been developed to integrate powertrain control, unifying engine control and automatic transmission control. Implementation of advanced control theory is one of the major issues in this field and will benefit greatly from microcomputer performance improvements. This paper commences with a discussion of the trend toward higher performance requirements in integrated powertrain control, driven by a new concept in control: variable transmission shiftpoint control based on vehicle operating conditions. The latter portion of the paper describes a new 16-bit dual CPU system for integrated powertrain control. The system achieves an improvement in processing through high-density communication.
1990-02-01
Technical Paper
900232
Günther Plapp, Martin Klenk, Winfried Moser
: Misfiring of the engine can cause damage to the catalyst within short time and increase emissions. Under misfiring conditions, unburned fuel and oxygen are pumped into the catalyst, where its combustion heavily increases the temperature. For this reason there is a demand for fast detection of misfiring. Once judged, one can take countermeasures to avoid further temperature rise. Two methods of misfire detection with the prospect of future use in series production are discussed. A first approach uses the trace shape of the λ-sensor signal for evaluation. The second approach uses the speed fluctuations of the engine for detection. Efficient algorithms give the possibility of misfire detection in the full load-speed range with reasonable effort to protect the catalyst. However there will remain some misfire conditions, increasing the emissions above regulation limits, that cannot be detected by those methods.
1990-02-01
Technical Paper
900237
G. V. Stuart
Abstract Mathematical models of transient engine dynamics have traditionally been produced with analysis from first principles of the physical processes within the engine. However, system identification techniques allow a ‘black box’ model to be derived purely from experimental data. These discrete time models have the advantage of being both straightforward and in a form which is suitable for digital control algorithm design and implementation. This paper describes work which is underway to identify the transient dynamics of a four cylinder 2.0ℓ DOHC multi-point injection engine. The experimental arrangement allows the fuel injection for each power stroke to be individually controlled while data acquisition is synchronised with the engine crankangle. The requirements for the input signal to the engine are discussed and methods used for data analysis are described. Results showing the response of IMEP to perturbations in fuelling are presented.
1990-02-01
Technical Paper
900223
Shizuo Yagi, Yoichi Ishibasi, Hiroshi Sono
For the prediction of frictional mean effective pressure (Pmf), the experimental data of over 300 engines, including super high speed engines whose maximum revolutional speeds were up to 16000 rpm, were analyzed. It was found that Pmf is nearly proportional to a non-dimensional number given by piston stroke (S), mean equivalent crank diameter (Dcm) and cylinder bore (B). Its proportional constant consists of an engine speed dependent term and a constant term. We focused on the influence of pumping loss on the first term and made a tribological study on the second term. As a result of this research, regardless of cylinder configuration or maximum engine speed, Pmf can be estimated at the stage of engine designing.
1990-02-01
Technical Paper
900217
B. R. Hauser
The implementation of rubber coated metal gaskets, (RCM), into refrigerant compressors is valued not only for its replacement of the asbestos fiber material, but for reliability enhancements as well. The design of the gasket, however, must be considered because flat RCM gaskets do not have equivalent compressibility as compared to flat fiber gaskets. This can result in refrigerant leaks when flat RCM gaskets are used due to inadequate load distribution. Using Finite Element Analysis, (FEA), an embossment was designed for the RCM material which provided a well distributed seal pressure. Prototypes of the embossed RCM gaskets were created and their function empirically verified.
1990-02-01
Technical Paper
900219
R. Sullivan, S. Selkowitz
A preliminary analysis of the effects of glazing and ventilation on automobile cooling loads and air conditioner capacity was completed as part of the Environmental Protection Agency's efforts to reduce the release of chlorofluorocarbons (CFC) into the earth's atmosphere from automobile air conditioners. We investigated the characteristics of standard and sports model sedans using numerical simulations of the heat transfer processes under static soak conditions. We conclude that: Glazing is a major contributor to the cooling loads that dictate the size of automobile air conditioners. The use of new glazing technology in conjunction with other design features, e.g., ventilative cooling when parked, provides a viable means of reducing cooling system size in many parts of the country. Additional analytical and experimental investigations under highway driving conditions are needed to determine the magnitude of the cooling unit size reduction possibilities.
1990-02-01
Technical Paper
900214
Refki El-Bourini, Kazuo Hayashi, Tsunenari Adachi
: Current production automotive airconditioning systems have demonstrated the lower thermodynamic efficiency of HFC-134a versus traditional CFC-12 refrigerant. A loss in cooling performance was realized at low speeds and idle with the serpentine condenser and HFC-134a. However, with the proper system modifications and materials selection, HFC-134a has been successfully tested in one particular mobile air conditioning application. Better A/C system performance was achieved with HFC-134a when the OE serpentine condenser was replaced by a 30% greater heat transfer capacity condenser. This more efficient design is called the multiflow condenser. It also offers 50% less weight and 20% less refrigerant when compared to the present serpentine configuration on the application tested.
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