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Viewing 70801 to 70830 of 110627
1992-02-01
Technical Paper
920606
Thomas R. Fries, Thomas D. Jones
Accurately calculating speed from heavy truck skid marks can be difficult. As indicated in SAE article 910126“̈-.an accurate deceleration rate is often an elusive piece of the puzzle.” This paper is intended to add to work done by others in determining heavy truck deceleration rates and calculating speed from skid marks by using different deceleration rates through different portions of each skid length. Deceleration rates and skid lengths obtained from a test by the Washington Association of Technical Accident Investigators (WATAI)[2] will be used as a basis for an evaluation of the adjusted drag factor method for speed determination. The method is then used to compute truck speeds in a case in which a heavy truck left non-uniform skids of different lengths while braking and evasively steering.
1992-02-01
Technical Paper
920773
C. Julius Wang, David C. Baker
The reliability of an electronic sensor in the automotive applications is assessed using data from Fleet Test and proving ground Vehicle Endurance test. These nonfailure data are multiply censored at different mileage. Reliability analysis of data with no failure is rarely discussed in most reliability literature. This paper applies the Weibull maximum likelihood analysis based on known values of the Weibull shape parameter to extract useful reliability information. The well-known Weibayes and Weibest methods are subsets of the discussed approach. The sensitivity of the change of reliability levels over a range of Weibull shape parameter values is also examined in our case. The Huang-Porter (1991) approach of obtaining a reliability lower bound regardless of the Weibull shape parameter values is also applied and its potential of practical application is discussed. Practical limitations of all methods are discussed.
1992-02-01
Technical Paper
920249
Yukio Suzukawa, Kazuo Ikeda, Jun-ichi Morita, Akitoshi Katoh
As a demand for vehicles of higher functionality grows, automakers and material suppliers are devoting increasing efforts to develop technologies for greater safety, lighter weight, higher corrosion resistance, and enhanced quietness. The resin-sandwiched vibration damping steel sheet (VDSS), developed as a highly functional material for reducing vehicle vibration and noise, has been used for oil pans1) and compartment partitions2). First applied for a structural dash panel of the new Mazda 929, a Zn-Ni electroplated VDSS which allows direct electric welding has contributed to greater weight reduction as well as improved quietness.
1992-02-01
Technical Paper
920169
Yousuke Taniguchi, Hiroshi Aoki, Kenji Fujikake, Hisashi Tanaka, Motohiro Kitada
S The purpose of this study is to present a new method for controlling a car air conditioning system, in which the air temperature can be controlled to produce any level of occupants' thermal sensation by utilizing car occupants' skin temperatures as a controlling index. In this paper, an equation for a quantitative evaluation of car occupants' thermal sensation, in steady and non-steady states, by face skin temperature and its rate of change was developed and was confirmed by experiments in an environmental chamber to be applicable for all seasons with an accuracy of ±1 in the thermal sensation voting scale we used.
1992-02-01
Technical Paper
920311
E.A. Willis, J.J. McFadden
This paper provides a brief review of NASA's Rotary Engine Technology Enablement Program from 1983 through 1991, with primary emphasis on the CFD or Computational Fluid Dynamics approaches used since 1987. The main discussion includes both code development and applications to several particularly difficult internal airflow, fuel-air mixing and combustion-related problems. A summary of the final status of the technology is given.
1992-02-01
Technical Paper
920193
Sidney J. Lestz, Maurice E. LePera
A technology demonstration program was conducted by the U.S. Army to verify the feasibility of using aviation turbine fuel JP-8 in all military diesel fuel-consuming ground vehicles and equipment (V/E). Over 2,800 pieces of military equipment participated in a two and one-half year program accumulating over 2,621,000 total miles (4,219,810 km) using JP-8 in combat/tracked, tactical/wheeled, and transportation motor pool vehicles. Over 71,000 hours of operation were accumulated in diesel/turbine engine-driven generator sets using JP-8 fuel. Comparisons of various performance areas with baseline diesel fuel (DF-2) operation were made.
1992-02-01
Technical Paper
920132
Russell E. Vaiden
: In the past ten years, there has been a radical change in automotive engine and transmission sealing technology. For example, molded rubber gaskets have supplanted the traditional formed-in-place gaskets and cork rubber compositions as the preferred sealing mechanism. The vast majority of these new gasket designs are currently manufactured from silicone rubber (VMQ). Although VMQ has demonstrated an outstanding performance record since its introduction to these new applications, it does have several deficiencies which limit its use. For this reason, formulations based on alternative organic polymers have been developed and are available for use in applications where performance improvements are desirable. It is the intention of this paper to focus on optional elastomeric formulations which are now available to satisfy increasing warranty demands of the automotive power train.
1992-02-01
Technical Paper
920644
Kajiro Watanabe, Kazuyuki Kobayashi, Ka C. Cheok
Abstract Accurate information of the absolute speed of a vehicle, when available, can be vital in simplifying the control laws of an anti-lock braking system (ABS) and auto-traction system (ATS). A current meter for measuring the speed of a vehicle is to multiply the measured wheel rotation rate to the wheel radius. The approach often includes abrupt unpredictable errors due to slip and skid of wheels and a biased error due to the steady state slip. These errors are sources of difficulty in the implementation of an ABS that is based on the absolute speed of the vehicle. This paper describes an accurate rule-based Kalman filtering technique for estimating the absolute speed of a vehicle. The enhanced accuracy is achieved by employing an additional accelerometer to complement the wheel speed-based speedometer. The accelerometer measures the acceleration of the vehicle in its forward direction and may be corrupted as well by high frequency noise.
1992-02-01
Technical Paper
920826
J. Vardi, B. J. Kraus
The requirement by the U.S. EPA that highway diesel fuel be limited to no more than 500 parts per million by mass of sulfur after October 1993, will require an increase in hydrotreating severity to achieve the needed sulfur reduction. It is known that severe hydrotreating can produce problems with the performance of the fuel, one being the increased susceptibility of the fuel to oxidize during storage in the presence of air. Formation of high levels of peroxides in the fuel can lead to incompatibility with fuel system elastomers. To determine the potential for increased oxidation tendency with future highway fuels, Products Research Division of Exxon Research & Engineering Company undertook a study comparing current diesel fuels with prototype low sulfur blends. The indications from the study are that low sulfur fuels have an increased tendency for peroxide formation. Results with anti-oxidant additives are shown and prospects for additives to control the problem are discussed.
1992-02-01
Technical Paper
920409
Akihiro Yamauchi, Makoto Nagano, Tadashi Kimura
This paper analyzes the vibration of open-top cars known as lateral shake. The characteristics of the phenomenon were identified by means of road tests and a test method called the shake test was devised to reproduce these characteristics in order that the respective roles of the suspension, body and engine could be determined. On the basis of the analysis findings, a simple but practical simulation model was realized and used to investigate various methods of reducing lateral shake. The simulations indicated that although changing the natural frequency of the suspension has little effect, increasing the natural torsional frequency of the body and/or utilizing the engine as a dynamic damper results in a significant improvement. Further experiments conclusively demonstrated that by optimizing the body structure in accordance with FEM analysis results and optimizing the spring constant of the engine mounts, the level of lateral shake can be halved.
1992-02-01
Technical Paper
920363
K. Pattas, Z. Samaras, D. Sherwood, K. Umehara, C. Cantiani, O. Aguerre Chariol, Ph. Barthe, J. Lemaire
Abstract The first two of a series of traps retrofitted on a pilot fleet of 110 buses of the Athens Bus Corporation were removed for examination after 100,000 km of revenue service. These buses were gradually equipped with the ELBO Trap Oxidiser since the beginning of 1989 and are constantly operated on Cerium based fuel additive. The physical properties and the chemical composition of filters and ash residues were analysed by the filter manufacturers and the fuel additive producer. The results have shown that after two years of operation the filter material remained intact and the ash deposits (consisting mainly of CeO2) exhibit a limited interaction with the cordierite. More than 94% of these deposits are filtered by the monoliths and could be removed to a large extent with the application of conventional methods.
1992-02-01
Technical Paper
920680
Thomas Dreeben, Larry Millen, Marvin Wells, James Woolworth
Abstract The “Sac” is a small volume within the fuel flow path of an electronic fuel injector. In this study, it is defined as the volume between the valve seat (fuel shut off point) and the entrance to the final metering orifice of the injector. This sac causes fuel injectors to deliver uncalibrated excess fuel when the engine is operated under closed throttle, high manifold vacuum conditions such as vehicle decelerations or idle. This paper describes a simple mass balance model used to predict the effect of the sac volume on injector fuel delivery under extreme operating conditions. The model prediction compares directly with experimental results for injectors with different sac volumes.
1992-01-01
Technical Paper
890113
William A. Leasure, Jr., Sidney F. Williams, Jr.
When a heavy vehicle driver (or in fact a driver of any vehicle) makes a brake application that is too "hard" for conditions - especially when the vehicle is lightly loaded or empty and/or the road is wet or slippery - he is likely to lock some or all of his wheels. Under these conditions, the tractor can jackknife or the trailer can swing out of its lane (if it is a combination-unit vehicle) or the truck can spin out (if it is a single-unit vehicle). Incorporation of an antilock brake system addresses the wheel lock and resultant control loss.
1991-11-04
Technical Paper
916010
G. Ernst, E. Brühning, K. P. Glaeser, M. Schmid
Road accidents may involve collisions between vehicles of different weights under a variety of circumstances. It is rare for vehicles of equal weight to collide. The range of vehicle curb weights (masses) extends from less than 700 kg (e.g VW Polo) to over 2,000 kg (e.g. Daimler Benz, S-class). In accordance with the impact laws of mechanics, the consequences of collision involving smaller and larger vehicles are mostly more serious for the driver and passengers of the smaller vehicle. In the past, it has not always been possible to completely quantify the seriousness of accidents or the risk of being injured or killed in Germany because there is no direct link between vehicle mass and the seriousness of passenger injuries. All that is available at present is a study by an insurance association based on single accident cases. This analysis covered front-seat passengers using seat belts as well, but not only the drivers.
1991-11-01
Technical Paper
911305
Z.D. Yan, X.L. Yu, Z.Q. Hu, H.F. Chang, H.Q. Sheng, Z.X. Yin
This paper will summarize the theoretical and experimental achivements in the thermal load studies which have been done, especially determination of the heat exchange boundary conditions, some new methods will be proposed. This made it possible to predict the distributions of the temperature and the heat flux in heated components, when the engine is still in the design stage. Using the aformentional achievements in the thermal load studies, several types of the engines have been designed and developed. Those high speed small air-cooled diesel engines have been successfully applied to the agricultural and industrial multipurpose utilities in the wide area.
1991-11-01
Technical Paper
911306
T. Akaogi, M. Ogura, S. Daidoji
When the exhaust gas turbine diesel engine step in the working range of low speed revolution, the air flow capacity of compressor rapidly reduces, and it become almost unworkable state compared with the ideal super charging condition. It is considered that the effect of gas turbine output power appears sensitively unsuitable condition with the full of gas temperature, pressure, flow volume produced in actual operating gas turbine. In order to correct the effective state produced in lower speed range, the development of movable turbine nozzle vanes equipped with in turbine scroll are being watched with many interests by the reason of requirement. This report mainly concerns itself with authors intend to develop the movable gas turbine nozzle vane and to state the property and actual merit in detail.
1991-11-01
Technical Paper
911303
Bai Jing Sheng, Wang Song Qin, Feng Fu Qiang, Chen Shao Hong, Zhang Dong Sen, Sun Hong, Zhao Jin Cheng, Shi Hong
The key point of reducing idling pollutants from two-stroke engine is to improve gas exchanging quality. This paper proposed a new construction of air-head scavenging project- labyrinth air-head scavenging project. Test results prove that this project together with delaying ignition timing, increasing idling delivery ratio and high-energy ignition can make the idling pollutants of 1E46FM engine reducing from HC> 8000ppm to 5800ppm and CO from 4.8% to <2.0%.
1991-11-01
Technical Paper
911304
Louis H. Browning
Two Computer models were used to study abnormal combustion in a crankcase-scavenged two-stroke engine fueled on methanol. Experimental studies had shown that the octane rating of methanol in this engine was lower than that of gasoline when compared to known reference fuels. Through computer modeling, the abnormal combustion was shown to be a combination of auto and surface ignition resulting from high intake charge temperatures and high residual fractions inherent in crankcase-scavenged two-stroke engines. Precursors of knock were also shown.
1991-11-01
Technical Paper
911309
Jae Cheon Lee
The acoustic attenuator is so highly nonlinear and of high order that the observer design using the linear observer theory can hardly guarantee the robustness against the modeling error and uncertainties. In this paper, a state-space representation of an acoustic attenuator utilizing the electrical analogy is presented first, and the time domain response analysis is performed. The state-space model developed was validated by comparing the simulation results with the experimental results. Then, a nonlinear observer of the attenuator was designed based on the optimization problem which bridges the gap between nonlinear observer theory and its application. The observer performance was evaluated when modeling error existed to verify that the observer designed is insensitive to modeling errors and uncertain parameters. Satisfactory robustness and convergence properties of the observer were found.
1991-11-01
Technical Paper
911310
Peng Jia-Zheng, Hu Ya-Ai
SUMMARY The thesis shows, in details, the study of mixed application of water-blended and idling fuel-saving on an automotive vehicle through the principle of water-blended and idling fuel-saving of an engine, the description of advantages and disadvantages about water-blended and the method for operation.
1991-11-01
Technical Paper
911308
Kiyoyuki Minato, Mieko Iwata
Much attention has been paid in recent years to the enhancement of automobile performance and the improvement of fuel consumption at high speeds. Accordingly, it has become necessary to acquire a precise grasp of automobiles aerodynamic characteristics [1, 2, 3, 4, 5]. Compared with automobiles, however, the general level of interest in the aerodynamic characteristics of snowmobiles has remained low. This relative lack of interest is attributable to the fact that, because the area of the front projection of a snowmobile is comparatively small and the vehicle itself is very light, little emphasis has been placed on fuel economy. Moreover, it is attributable to the facts that improvements in aerodynamic characteristics of snowmobiles do not produce the dramatic effects that they do in automobiles, and finally because of the lack of strong demands in society for such improvement.
1991-11-01
Technical Paper
911314
Toshio Tsutsumi, Makoto Ohtsu
Abstract Motocross (Motorcycle Cross Country), a sport of motorcycle racing held outdoors in rugged natural terrain, was grown in Europe 1960. Then in the later half of the decade, the sport was introduced in the United States as a off-road motor sport as well for leisure. Bringing this outdoor sport of Motocross into baseball stadium, introduced a new sport of indoor Motocross, which is called stadium cross race. This stadium cross the retains showing unmeasurable growth each year world wide and they commonly call a Supercross race. As for supercross racing machine requires high riding technique, which is constituted by durable and high performance racing machines. The engine which is constituted by 2-stroke single cylinder, must be in balance with high power and quick precise response. The suspension system is also a major importance for supercross racing. Landing stability for large jumps, and handling stability for the washboard portions is essential.
1991-11-01
Technical Paper
911311
A.M. Ibrahim, Y.M. Abdel-Rahim, I.G. Ibrahim
A comprehensive investigation of the chemical equilibrium thermodynamic properties (M, CP, h and s) of the products of combustion of ethanol-octane and methanol-octane blends in air is presented. Complete spectrums of fuel blends (ranging from pure octane C8H18 to pure ethanol C2H5 OH or methanol CH3OH), fuel-air mixtures (from very lean, ϕ = 0.15 to very rich, ϕ = 2.0) and combustion products temperature, T and pressure, P (in the ranges of 600-5000 K and .5-1000 ata) are examined. Mole fractions of the most important 16 product species are calculated and discussed. The extent of disscoiation and energy loss terms are defined, evaluated and discussed. The real gas effect on these properties in the low temperature range (600 - 2400 K) when evaluated by correlated equations of Ref. (1)* are found to be insignificant.
1991-11-01
Technical Paper
911312
Hans Holzleltner
Two-stroke racing engines are nowadays in a very high developed stage and are used specially in racing disciplines, where extremly high power to weight ratios are required. But the type of racing sometimes leads to a completely different demand in performance and power band. Two of this contrary applications are Kart and snowmobile racing. This investigation shows, why the demand is so different and what measures on the engines have to be taken, to accomplish this requirements.
1991-11-01
Technical Paper
911290
Katsuhiko Matsuo, Nobuyuki Tani
HST(Hydrostatic Transmission) of BANTAM DUTY series is newly developed compact and general purpose HST. This HST is constituted with axial piston pump & motor of maximum working pressure 14.7MPa has characteristics such as epochal compact, light weight, high efficiency, high reliability, and cost effective. The structure with 6 basic model series of 3 framesize enables it to be used as all kind of small vehicles. In this paper, we explain the basic design concept, technical characteristics of this BD series with applicable cases.
1991-11-01
Technical Paper
911289
Yutaka Furukawa, Eiichiro Ikeda
We have successfully developed a light-loading no-stage variable speed power transmission using V-belt for agricultual and general industrial machines enabling easier manipulation and faster transmission than conventional V-belt transmissions. This paper describes the fundamental operation principle of the transmission, and reports the results of the experimentl studies. The V-belt no-stage transmission is a power transmission which allows the ratio of the revolutions on the input axis to that on the output axis to be controlled with no stage by changeing the winding pitch diameter of a single V-belt put on a variable width (variable speed) pulley. The new transmission we have developed (called VSW-type transmission) is characterized by the linkage of the open/close of driving and driven pulleys with the fundament al principle to reduce operation load during ratio change.
1991-11-01
Technical Paper
911286
A.M. Ibrahim, Y.M. Abdel-Rahim, I.G. Ibrahim
The paper presents approximate formulations for the thermodynamic properties of combustion products of any specified hydrocarbon fuel (CcHhOoNn) in air as functions of fuel type, equivalence ratio, temperature and pressure. Real gas virial equations of state for product species are incorporated in the analysis and their effects are included in the formulations. Results of the paper are compared with other detailed chemical equilibrium calculations for three diverse fuels (octane C8H18, methanol CH3OH and coal CH.17O.05N.02) under different conditions with satisfactorily agreement.
1991-11-01
Technical Paper
911287
Domenico Laforgia
A mono-cylinder engine was built, because of its costs and the semplicity of designing, as flexible prototype. A scavenging system with four ports, two by two simmetrical, was chosen to respect the modern theory of scavenging optimization. The scavenging flow was supplied by a carter-pump; it has been used as first experimental solution. The prototype has been entirely realised and the following experimental measurements have been carried out: the pressure in combustion chamber, in carter pump, in pipes and injection system, as well as the fundamental parameters of engine functioning.
1991-11-01
Technical Paper
911294
Robert Craven, James E. Smith
Balancing to date, of the Stiller-Smith Mechanism, has been for a symmetric configuration. If two pistons are moved closer to the center of the engine to minimize spatial requirements and also reduce weight, then the mass center of the inner mechanism no longer travels in a circle about the center of the engine. It is shown how the overall balancing of the engine is not compromised using the example of a small 8-cylinder engine. The effects of the non-symmetry on the performance of the linear bearing is presented and the resulting additional engineering concerns are discussed.
1991-11-01
Technical Paper
911293
Kazuyuki Shiomi, Hiroshi Mizuguchi
This paper deals with a method of isolating vibration which can be applied to four - stroke, inline, two-cylinder engines with an even firing interval of 360°. This new method effectively isolates 1-st order vibration by positioning engine components and mountings in a way that provides the engine with an oscillation center without the use of additional balancer shafts. The conditions required for the existence of such an engine oscillation center, its movement and the effectiveness of this vibration isolation method are theoretically studied. This method will then be applied to a lawn tractor.