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Viewing 70801 to 70830 of 105108
1989-02-01
Technical Paper
890442
Richard L. Bell, Vinodkumar Mehra
Automobiles from all parts of the world are now being built with plastic fuel tanks made from high density polyethylene (HPDE). The most difficult aspect of the current manufacturing process for meeting environmental regulations is the need to work with hazardous chemicals such as fluorine and sulfur trioxide to reduce hydrocarbon permeation. Laminar barrier technology is a barrier process under development which meets EPA requirements, reduces costs and eliminates environmental and employee safety concerns. Laminar technology is a patented, one-step barrier process where 4-5% of a barrier resin is dry blended with HDPE and processed using standard blow molding equipment. The finished fuel tank will contain an integral barrier composed of overlapping barrier resin platelets within the HDPE matrix. Regrind can be effectively utilized and there are no restrictions for secondary assembly techniques such as hot plate welding.
1989-02-01
Technical Paper
890443
Hidetoshi Takede, Narumi Hata
AN INVESTIGATION was conducted to predict the fatigue life of a radiator fan carrier made of glass fiber reinforced polypropylene under a cyclic load of a constant amplitude. As a result we could establish 1) a stress analysis technique and 2) a testing method for material strength, both prerequisites for prediction of fatigue life of polymers.
1989-02-01
Technical Paper
890431
Oner Arici, Lawrence W. Evers, Randy L. Nussio
Lean limit characteristics of a pneumatic port fuel injection system is compared to a conventional port fuel injection system. The lean limit was based on the measured peak pressure. Those cycles with peak pressures greater than 105 % of the peak pressure for a nonfiring cycle were counted. Experimental data suggests that there are differences in lean limit characteristics between the two systems studied, indicating that fuel preparation processes in these systems influence the lean limit behaviors. Lean limits are generally richer for pneumatic fuel injection than those for conventional fuel injection. At richer fuel-to-air ratios the pneumatic injector usually resulted in higher torques. A simple model to estimate the evaporation occurring in the inlet manifold provided an explanation for the observed data.
1989-02-01
Technical Paper
890433
Chen Xlaofu
In this paper, based on an amount of research literature which has been recently published in Chinese magazines, the author has reviewed the present situation of research into alternative fuels for automotive use in China. Especially in respect of studying methanol fuel, a large scale test was performed. About 500 trucks travelled for more than 60,000 ton-km in the field test and a large amount of important data was gained. A brief resume is given of progress of research in China into applying methanol fuel to other uses. In this paper, the author's opinion about further development of alternative fuel in China is presented.
1989-02-01
Technical Paper
890429
Hiroaki Yonetani, Tetsujyu Nakamura, Itaru Fukutani, Eiichi Watanabe
Two hybrid Combustion engines, wherein a premixed gasoline homogeneous charge was ignited by a small amount of injected diesel fuel under high compression ratio, were made and tested by modifying crankcase scavenged 2-stroke cycle diesel engines, one uniflow scavenged with an open chamber and the other loop scavenged with a prechamber. It was found that the premixed gasoline was effective not only for decreasing the fuel consumption but also for reducing the smoke density both in the heavy and over-load regions. The mixing ratio of the gasoline and diesel fuels, the injection timing of the diesel fuel and the compression ratio were found to be the main factors affecting the performance of these hybrid combustion engines. The effect of inlet throttling on the brake specific fuel consumption (BSFC) in the light load region was also examined.
1989-02-01
Technical Paper
890430
Kazuyoshi Namiyama, Hiromi Nakamura, Kakuro Kokubo, Daijiro Hosogai
This paper describes a fuel atomizer developed for S.I. engines based on ultrasonic vibrations. As the spray is characterized by fine droplet size and low penetration, it facilitates fuel movement and the formation of a homogeneous mixture. The spray behavior of this atomizer is easily influenced by ambient air motion. Therefore, the spray is most effectively delivered to the cylinders by precise injection timing. The ultrasonic atomizer disperses a fine spray over a wide flow rate range. A single cylinder engine fitted with the atomizer showed advantages in combustion speed and transient response performance. When used in a commercial SPI engine, the ultrasonic atomizer maintained constant A/F distribution in all cylinders with no geometrical modification of the intake manifold. In cold weather conditions, the atomizer demonstrated excellent startability.
1989-02-01
Technical Paper
890436
Takeyuki Kamimoto, Miki Yagita
The present paper describes the particulate formation in diesel flames considering the flame structure and its similarity to that of gaseous turbulent diffusion flames. A comparison of spatial variations of soot concentration, equivalence ratio and flame temperature between diesel flames and turbulent diffusion flames reveals the facts that soot particles are mostly farmed in a region where the equivalence ratio is near stoichiometric and the flame temperature is the highest in both flames, and that in diesel flames this region exists generally near the flame tip. A close inspection of high speed photographs of diesel flames suggests the three major routes of soot emission from diesel engines: quenching of flamelets detached from the flame tip due to 1) the flame impingement onto the wall; and 2) cooling of the flamelets by the bulk air; and 3) survival of soot containing flamelets inside the flame.
1989-02-01
Technical Paper
890437
R. Barbella, C. Bertoli, A. Ciajolo, A. D'Anna, S. Masi
The formation and oxidation of soot, light and heavy hydrocarbons, CO, CO2 and NOx in a D.I. diesel engine have been studied by means of direct fast sampling and chemical analysis of the combustion products collected during the combustion cycle. Particular attention has been paid to the histories of each fuel hydrocarbon class analyzing the chemical transformations that the paraffins, and monoaromatic and polyaromatic compounds, contained in a diesel fuel oil, undergo during the combustion cycle. This approach is able to give information on the origin of soot and heavy hydrocarbon emission from a diesel engine. The concentration of the heavy hydrocarbons decreases during the early stages of the combustion cycle and their profile corresponds roughly to the fuel disappearance rate because of the chemical similarity with the fuel compounds.
1989-02-01
Technical Paper
890434
Reda M. Bata, Alvon C. Elrod, Thomas P. Lewandowskia
This work was undertaken to evaluate butanol as an alternative fuel for internal combustion engines- The evaluation was made by measuring the performance of a four-cylinder automotive spark-ignition engine when fueled with four different Fuels: (a) 100% unleaded-regular fuel was used for reference. (b) the test fuel, iso-butanol, was blended in amounts of 5, 10, 15, and 20% by volume with gasoline for the subject evaluation. (c) for comparison purposes, a 10% methanol-gasoline blend was used. (d) also for comparison, a 10% ethanol-gasoline blend was used. It was found that there was only about 2.5% reduction in the thermal efficiency of the test engine when 20% of the gasoline was replaced by butanol (the brake-specific-fuel-consumption, BSFC, increased by about 6.5%). Butanol was shown to be superior to both methanol and ethanol in terms of higher thermal efficiency (and correspondingly lower BSFC).
1989-02-01
Technical Paper
890435
G. M. Pannone, R. T. Johnson
Lean turbocharged operation with methanol was characterized using a single-cylinder spark ignition engine. Efficiency, exhaust emissions, and combustion properties were measured over a range of air/fuel ratios at two naturally-aspirated and three turbocharged conditions. When compared to stoichiometric, naturally-aspirated operation, the lean turbocharged conditions improved efficiency while reducing carbon monoxide and oxides of nitrogen emissions. However, unburned fuel and aldehyde emissions increased. If used in conjunction with an oxidizing catalyst and appropriate feedback controls, lean turbocharged operation has the potential of improving efficiency and exhaust emissions performance over a stoichiometric, three-way catalyst system.
1989-02-01
Technical Paper
890457
Kazuo Inoue, Osamu Kubota, Noriyuki Kishi, Shunji Yano
A turbocharger which has four pairs of fixed vanes and movable vanes inside the turbine scroll was developed. A 1.2-liter experimental gasoline engine with this turbocharger was made and mounted in the body of a passenger car. This variable-geometry mechanism did not need a waste-gate system. Results of bench tests showed that this engine generated a 93.3 kPa (700 mmHg) boost pressure over a 6,000 rpm range. This paper presents the mechanism, operation, and performance data of this variable-geometry turbocharger, as well as the performance data of the 1.2-liter experimental engine and this passenger car.
1989-02-01
Technical Paper
890456
Klaus Heikrodt
SUMMARY PIERBURG has developed a mechanical supercharger working according to the principle of an inner-axle rotary piston machine. The inside rotor has 3 teeth while the outer rotor has 4 teeth, representing the KA ratio of 4:3. In a comparison with other supercharger types the advantages of the PIERBURG rotary piston supercharger (DKL) become evident. The DKL may be used for spark ignition engines with a power range of up to approximately 250 KW and for diesel engines up to approximately 180 kW. The supercharger is designed so that the adaptability to the absorption volume of the engines is achieved only by a length variation. With the exception of the rotors, the housing and the connection pieces, all components are designed in such a way that they may be used as identical parts for all supercharger sizes. The rotors are extruded profiles.
1989-02-01
Technical Paper
890463
Shigeru Yoshikawa, Ryunosuke Furusawa, Masataka Arai, Hiroyuki Hiroyasu
The effects of engine parameters, such as spray characteristics and combustion chamber geometry on performance and exhaust emissions in a small D.I. diesel engine were investigated to find out the optimum way of improving the engine. Diesel spray injected into a high-pressure vessel was photographically analyzed to guess the spray behavior in a firing diesel engine. The ratio of hole length to the diameter of a nozzle (L/D) was varied from 3 to 7 as the main parameter of the nozzle. Piston cavity diameter and intake swirl were chosen as the other parameters. The effect of the above parameters was investigated in terms of brake specific fuel consumption (BSFC), exhaust smoke, nitric oxides (NOx) and total hydrocarbon (THC). The L/D of the nozzle is concluded to be of major importance in terms of BSFC and THC emission. Smaller piston cavity diameters lead to lower exhaust smoke, but to a higher level of NOx emission.
1989-02-01
Technical Paper
890461
G. Filtri, L Morello, B. Stropplana
The development of a new family of prechamber diesel engines, based on a technological commonalty with the gasoline engines is reported. The range of diesel engines, all of them four-cilynder-in line, consist of 3 displacements: 1365cc - 1697cc - 1930cc either naturally aspirated or turbocharged. Mention is also made of their most significant technical innovations about their architecture and combustion chambers, and the main components such as block cylinder, head, crankshaft, connecting rods, pistons, timing gear and injection pump control, intake and exhaust manifolds.
1989-02-01
Technical Paper
890460
L. Morello, P. Martinez
Because of the fuel cost rise, due to the first world oil shortage, in the early seventies, it was decided to initiate a research programme aimed to the evaluation of the potentiality of a small displacement, high speed, direct injection diesel engine in terms of fuel saving. The engineering target was to develop a D.l. engine capable of operating with a satisfactory level of noise, emissions and smoke in the wide speed range required for passengers cars application. More than 12 years have been spent in research and development since the first preliminary tests were carried out on a single cylinder research engine in the early 1976. As a result of this long activity, was launched on June 1988 the CROMA T.D.2.0, the first passenger car in the world powered by a direct injection diesel engine. The paper describes the evolution of the project from the first research engines up to the 4 cylinder 1.9 liter production engine.
1989-02-01
Technical Paper
890450
Angelo De Vita
The combustion of diesel fuel emulsions with immiscible, low-boiling point liquids, such as water and lower alcohols, presents some interesting outlooks. A study has been carried out in order to determine the effects on the engine performances and exhaust emissions of ethanol and water as internal phases in diesel fuel unstabilized emulsions - directly formed in the injection line. Using a four cylinders, direct injection, water-cooled, diesel engine fed with ethanol emulsions (at 10, 20, 30 and 40 mass percentages) and water emulsions (at 10 and 20 mass percentages), data were obtained, the engine speed varying, at full load, from 1100 to 2000 rpm. Comparison with the diesel fuel operation was made by using two different criteria: constant total energy input rate and constant total mass flow into the engine, Further experiments, varying the load and the injection timing, were also carried out.
1989-02-01
Technical Paper
890449
Minoru Tsukahara, Yasufumi Yoshimoto, Tadashi Murayama
To improve engine performance parameters such as smoke, NOx, and BSFC in a DI diesel engine, water-in-gas oil emulsified fuel was used without high pressure or high injection rate. It was confirmed that when compared with high pressure and high injection rate operation with gas oil, emulsified fuel gives significant reductions in NOx concentration, improved fuel economy, and reduced smoke density at ordinary injection pressure and retarded timings.
1989-02-01
Technical Paper
890448
Mariusz Ziejewski, Hans J. Goettler
The flow of diesel fuel through multi-hole injection nozzles is well understood. There are, however, no comprehensive experimental results for the design of injection nozzles for alternate fuels. A steady state flow generator was designed and employed to analyze the effects of the physical fuel properties and the needle lift on the discharge coefficient for the nozzle orifice. Three fuels were tested: diesel reference fuel, a 50/50 mixture of diesel fuel and sunflower oil, and 100%. sunflower oil. The fuel viscosities range from 3.0 cS to 30.0 cS at 40°C. Five injection pressures ranging from 3.5 to 13.8 MPa, and eight increments of needle lift between 0.031 and 0.940 mm were used in this investigation. A significant influence of needle lift, injection nozzle pressure, and physical properties of fuels on the flow coefficient in the normal operating range of a typical diesel engine was proven.
1989-02-01
Technical Paper
890446
George S. Baranescu
A new system which has the capacity to inject and control the combustion of coal slurries in diesel engines is describe. The system eliminates the negative impact of coal slurries on the injection process, improves combustion of coal slurries, eliminates or greatly reduces the wear of the fuel delivery hardware, and prevents the nozzle clogging.
1989-02-01
Technical Paper
890455
Hidetsugu Matsubara, Kazuya Miyashita, Yuichi Iguchi, Shinya Tanaka, Kazuho Akiyama, Fusayoshi Nakamura
Recently, mechanically driven superchargers are being manufactured and applied to engines in order to increase the torque in low speed range and improve acceleration response. In our study, four types of positive displacement superchargers were picked up and the engine performance tests were carried out with each of them. The results were compared to each other, and finally, the advantage of a screw type supercharger was confirmed. At the same time in this paper, three types of high technology turbochargers are introduced, which are superior to the conventional ones from the viewpoint of low speed characteristics, transient response, and so on. Effectiveness of high technology turbochargers were described here with the test results.
1989-02-01
Technical Paper
890454
Mitsuo Hitomi, Yasuhiro Yuzuriha, Kazuyuki Tanaka
The supercharged diesel engine with a pressure wave supercharger (PWS) has achieved a high torque over the entire speed range in a quick response while maintaining the low fuel consumption as a small diesel engine. This is the result of adopting a high efficient supercharger based on the unique construction of PWS. Lower inlet and exhaust flow resistance, earlier inlet-close timing, etc., are specially important for engine with PWS. Another advantage is less unturned fuel emissions.
1989-02-01
Technical Paper
890453
Hermann Hiereth
For study purposes, an improved Pressure-Wave Supercharger (PWS), without belt drive, was investigated and adapted to a Mercedes-Benz passenger car diesel engine. Tests were performed both on the test bench and in a car of the Mercedes-Benz compact class. Characteristics, advantages and drawbacks of the new system will be shown and discussed.
1989-02-01
Technical Paper
890549
Vidyadhar Ashok Bhajekar, Dennis A. Guenther
Composite material roof structures for multipurpose vehicles are comprised of a composite shell molded without metal frames as in most automobile rooftops. This paper experimentally analyzes the roof structure performance for a static uniformly distributed load over the roof surface and examines the tensile properties, effects of high temperatures and sound absorption characteristics of the random, chopped glass fiber reinforced epoxy resin material. The roof performance includes the load-strain history and the load-deflection behavior of the structure.
1989-02-01
Technical Paper
890546
Karen M. Lombardo
The vibrational and acoustical behavior of components is of major concern to many design engineers. Unchecked vibration can lead to misalignment, accelerated part wear and noise. The automotive industry is especially concerned about noise and vibration levels associated with engines, compartments, brake systems, pulley systems, etc. A good design coupled with the best fabrication material should help to ensure a quieter and more vibrationally stable system. This study evaluates the vibrational and acoustical properties of thermoset composites, steel and aluminum.
1989-02-01
Technical Paper
890547
Jacky C. Prucz, Jospeh G. D'Acquisto, James E. Smith
The potential benefits of using advanced fiber-reinforced composites as an alternative to metallic alloys has been investigated for the design and fabrication of connecting rods in motion conversion mechanisms for internal combustion engines. Two types of mechanisms have been selected for this analysis: the common slider-crank mechanism and the new. Stiller-Smith Mechanism, in which the crankshaft is replaced by a floating gear system. An improved finite-element elastodynamic model, which includes the effects of longitudinal, bending and shear deformations, has been developed in order to quantify the relationships between the levels of bearing loads and vibrations of such mechanisms and the material design of their connecting-rods. An extensive parametric study has been conducted on the material system, the lay-up and the cross-sectional dimensions of elastic connecting rods, made of helically wound composite materials.
1989-02-01
Technical Paper
890548
Regu R. Ramoo, Dennis A. Guenther
The roof structures of light utility vehicles are often comprised of a single composite shell without the usual steel or aluminum frames found on conventional passenger automobiles. This study analyzes the geometry of such structures in relation to their performance during rollover accident and roof intrusion. For a given set of material properties and roof impact velocity, their exists an optimum value of roof stiffness that would minimize the impact energy, manifested in a rollover accident, that would be transmitted to the occupant compartment. This work shows the effects of various geometric parameters on the amount of elastic strain energy that can be absorbed during deformation of the rooftop. The optimum roof geometry was determined to minimize the possibility of, if not the severity of, occupant injury.
1989-02-01
Technical Paper
890540
Hideo Takai, Tohru Futami, Hidetoshi Kanegae, Hidetoshi Inagaki, Katsunori Oshiage
This paper describes a multiplexed communication protocol matched to vehicle diagnosis, which has become more complicated due to the greater sophistication of Electronic Control Units (ECUs). The diagnostic data link must be both flexible enough for complex applications and economical enough for most ECUs. First, an asynchronous communication method controlled by an external clock, one function of a CPU with UART, is employed to minimize ECU hardware cost. Second, a polling/selecting method comprising a set of diagnostic commands and a practical data link procedure is developed to minimize the ECU software burden. The result is a cost effective, easy-to-protocol.
1989-02-01
Technical Paper
890541
John D. H. Harris, Nigel M. Bailey
AUTOLAN is a Class C multiplexing system suitable for use with realtime control systems. It fully conforms to the SAE Multiplex Subcommittee's proposed definition of a Class C system in that: Repetitive and Bursty data transfers are possible Handshaking can be implemented More than 10 Nodes can be handled Latency less than 5 millisecond Bus rate 4 Mbits/sec It can be used as a Class B system to provide data communication between microprocessor controlled assemblies. It can be used as a Class A system to replace the conventional body wiring harness. The transmission media is a dual twisted pair cable. Shielding may be required in extreme radiant field conditions, such as may be found in electric traction systems with a power rating greater than 500 HP. AUTOLAN does not require a microprocessor at each Node. Rather, for Class C, the system microprocessor drives the AUTOLAN network, whose nodes act as its remote I/O ports.
1989-02-01
Technical Paper
890542
N. Gresty, A. R. Phillips
1) ABSTRACT The recent approval by the SAE Motor Vehicle Council of the serial protocol J1850 is a major milestone in the development of an open and flexible network approach to vehicle wiring. However, it is now necessary to evaluate the practical implementation of the protocol in some real vehicle applications. This paper describes one such exercise which considers a three station installation including the doors and a central body computer function, together with a diagnostic capability. It is, of course, anticipated that this simple system will be extended to include other areas of the vehicle as confidence is gained in its performance and the benefits of system integration are realised.