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Viewing 1 to 30 of 58951
2012-06-13
Technical Paper
2012-01-1537
In industrial automotive transmissions, several noises can't be avoided such as gear rattle and gear whine noises. Indeed they result from the choice of gear technology. They just can be reduced by an appropriate design. It is widely acknowledged that gear whine noise is mainly due to transmission error, which depends on many parameters such as driveshaft deflection, gear stiffness and operating torque. All these parameters are not necessarily well-known, which may sometimes result in the choice of a gear geometry that doesn't minimize transmission error. That can lead to customer claims once the vehicle is manufactured. To cope with whine noise customer claims, we investigated a statistical gear optimization method. The principle is to use whine measurement data base on benches to find the best geometry against whine noise after a statistical treatment. The main advantage is that it is not necessary to know precisely all the parameters involved in whine noise.
1990-02-01
Technical Paper
900255
Shigeki Sugiura, Toshio Yamada, Tokuta Inoue, Koji Morinishi, Nobuyuki Satofuka
Multi-dimensional code has been developed to simulate the effect of geometry on mass flow rate and flow pattern in the induction system of an internal combustion engine. The unsteady compressible Navier-Stokes equations in general curvilinear coordinates are solved by a new method of lines. In the method of lines, the governing equations are spatially discretized by a finite difference approximation and the resulting system of ordinary differential equations is integrated. As a time integration scheme, we newly propose to use the rational Runge-Kutta scheme in order to efficiently simulate the flows in the induction system. The domain-decomposition technique is introduced so that body-fitted structured grid can be easily generated for such complex geometry as a real intake port shape. The present code is applied to 2 and 3 dimensional steady flows in intake port/cylinder assembly with a valve.
1990-02-01
Technical Paper
900251
MarK J. Jennings, Thomas Morel
An important aspect of calculation of engine combustion chamber heat transfer with a multi-dimensional flow code is the modeling of the near wall flow. Conventional treatments of the wall layer flow employ the use of wall functions which impose the wall boundary conditions on the solution grid points adjacent to solid boundaries. However, the use of wall functions for calculating complex flows such as those which exist in engines has numerous weaknesses, including dependence on grid resolution. An alternative wall modeling approach has been developed which overcomes the limitations of the wall functions and is applicable to the calculation of in-cylinder engine flows. In this approach the wall layer flow is solved dynamically on a grid spanning a very thin boundary layer region adjacent to solid boundaries which is separate from the global grid used to solve the outer flow.
1990-02-01
Technical Paper
900253
D. H. Gibson, W. A. Mahaffey, T. Mukerjee
This paper details the development of a mathematical model to simulate the incylinder processes in the Caterpillar 1.7L Diesel engine and the results obtained during compression stroke and early part of the combustion stroke. The model includes accurate representation of the geometry of the 1.7L combustion chamber via Body Fitted Coordinates (BFC) which conform to the shape of the piston-dish and cylinder. Also included are the combustion model and evaporation model. This 3-D model predicts average cylinder pressure and temperature variations with degree crank angle which are in good agreement with Caterpillar measurements for this engine.
1990-02-01
Technical Paper
900252
Kang Y. Huh, I-Ping Chang, Jay. K. Martin
- Three different models, the law-of-the-wall, a modified law-of-the-wall, and an approximate one-dimensional solution to the energy equation are compared for the spatially-resolved prediction of engine heat tranfer. The multidimensional hydrodynamic code KIVA is used for the fluid mechanic simulation. Two different engine geometries are studied; one being a pancake-shaped chamber, and the other a bowl-in-piston geometry. The comparisons are done for a range of initial conditions of gas flow. Rates-of-pressure-rise were also varied to represent rates typical of those encountered in motored engines, and those found in fired engines. Comparisons with experimental results show that the heat transfer predictions using the law-of-the-wall may be in error when source terms such as the transient, work and chemical energy terms have a significant effect in determining the temperature profile in the boundary layer.
1990-02-01
Technical Paper
900475
Hiro Hiroyasu, Masataka Arai
The objective of this paper is to summarize experimental results which were previously reported by the authors and to derive many useful empirical equations concerning the diesel fuel sprays. The empirical equations for break-up length, spray angle, spray tip penetration and drop size distribution of the diesel sprays are introduced to discuss the internal structure of the spray. According to the effect of injection pressure and ambient pressure on the break-up length and drop size of the diesel spray, the spray structure can be divided into two categories; incomplete and complete sprays. The equations which express the break-up length and mean diameter of the incomplete and complete sprays were obtained using different techniques according for the dominance of one or more break-up mechanisms.
1990-02-01
Technical Paper
900467
Hideaki Kobayashi, Eiji Kawa, Yung S. Chen, Kajiro Watanabe, Hiroyuki Ishizuka
This paper describes how to realize an accurate, compact, and economical fuel gauge by the pneumatic method for deformed and flexible tanks which shake and vibrate, whose attitude changes and in which liquid sloshes and the temperature changes. The basic concept employed in the pneumatic method involves the use of the ideal gas law. The volume of liquid in a closed tank can be obtained by subtracting the volume of gas in the tank from the tank capacity. To determine the gas volume, both a reference tank attached to the main tank and the main tank were subject to the sinusoidal displacement. From the equations based on the dynamics of the pressure in the main tank derived from the ideal gas law and flow of gas thought a pipe, relations were obtained that gave the gas volume in the main tank from the filter pressure signals in the both tanks.
1990-02-01
Technical Paper
900479
Norimasa Iida, Kou Hirawo, G. Takeshi Sato
The process of forming mixtures of injected fuels and ambient air has significant effects on the ignition and combustion process in the direct injection engine. In these engines fuel is injected intermittently and fuel jet impinges on a combustion chamber wall. This study deals with a fundamental experiment on the mixing process of the transient gas jet together with the instantaneous concentration measurement and statistical analysis of the transient turbulent mixing process in the jet. Helium or carbon dioxide is injected at constant pressure into quiescent atmosphere through the single shot device. This paper presents a laboratory automation system for measuring the characteristics of transient gas jet and processing the data. A discussion on the process of mixture formation of transient gas jets impinging on a wall is carried out with time- and space- resolved concentration distribution.
1990-02-01
Technical Paper
900480
C. Arcoumanis, E. Cossali, G. Paal, J. H. Whitelaw
The spatial and temporal characteristics of a diesel spray injected into the atmosphere through a multi-hole nozzle used in small DI Diesel engines have been investigated by laser techniques as a function of pump speed and load. The results showed that spray tip penetration and velocity depend on injection frequency rather than injected volume and the spray is asymmetric during the early and main part of the injection period. In the time/space domain different structures have been identified within the injection period, with the early injection period characterized by a well atomized cloud of droplets, the main period by the spray head and a dense core and the late injection period by the disintegrating dense core and the spray tail. IN DIRECT-INJECTION DIESEL ENGINES for passenger cars, fuel is injected through multi-hole nozzles at high pressure to promote mixing with the rapidly swirling air inside the combustion chamber.
1990-02-01
Technical Paper
900481
Toshikazu Kadota, Fu-Quan Zhao, Katsuya Miyoshi
Laser Rayleigh scattering was applied for the remote, nonintrusive measurements of the time history of the transient fuel vapor concentration in the combustion chamber which was caused by the timed injection of unleaded regular gasoline, n-Pentane and n-Hexane into the intake port of a motored automotive spark ignition engine. The results denonstrated that the fuel vapor concentration increased with the time elapsed from the start of the fuel injection and reached a peak after which it decreased during the intake stroke. It showed a very slight increase during the compression stroke. It was also revealed that the fuel vapor concentration increased with an increase in the quantity of fuel injected, the engine speed and the fuel injection pressure. It showed a maximum as a function of the fuel injection timing.
1990-02-01
Technical Paper
900483
Hisamitsu Takagi, Toshihisa Ohno, Tsuyoshi Asanuma
Instantaneous temperature of in-cylinder gas provides a lot of useful and local information for analyzing the combustion process in an internal combustion engine, so many optical pyrometries have been proposed and developed. Among others, the infrared monochromatic radiation pyrometry is considered to be more applicable to a practical engine due to requirement of only a single optical window, whereas two optical windows are indispensable for the conventional infrared absorption pyrometry. In this paper, the former pyrometer is used to measure the mean gas temperatures averaged on an optical path (or cylinder diameter) of a spark ignition engine, of which a prechamber is connected to the main chamber by a torch nozzle of various area sizes.
1990-02-01
Technical Paper
900476
J. C. Haylock, Antonio Addeo, A. J. Hogan
Recent technological advances have made thermoplastic olefins a viable material for automotive soft interior trim. Targeted at replacing PVC skins, polyurethane foams, and substrates made from traditional styrenics, these new polypropylenes can be used in such applications as instrument panels, door panels, consoles, and seating. They offer many advantages over current materials in these stringent applications. This paper describes the olefinic materials that are suitable for soft interior skins, polyolefin extruded foam sheets that can be used in a laminate with the skin, rigid olefin compounds that are used for substrates, and the process to use these materials in manufacturing soft interior trim components.
1990-02-01
Technical Paper
900477
Toshikazu Kadota, Shuhji Mizutani, Chinn-Yuan Wu, Mitsunori Hoshino
An experimental study was made of the time and space resolved measurements of the diameter of the fuel droplets inside the combustion chamber which were resultant from the timed injection of liquid fuel into the intake port of a motored automotive spark ignition engine. The determination of the individual droplet diameter during the intake and the compression strokes was based on the intensity of the light scattered from the droplet which was subjected to the monochromatic irradiation of He-Ne laser with uniform intensity profile. A theoretical analysis was also done to simulate the evaporation history of a fuel droplet subjected to the highly transient environments in the combustion chamber of the engine. The results showed that the droplets survived at the last stage of the compression stroke while their diameters decreased with crank angle elapsed due to evaporation. The effects of engine parameters on the droplet diameter were extensively discussed.
1990-02-01
Technical Paper
900478
J. Emerson, P. G. Felton, F. V. Bracco
The objective of this study is to characterize the operation of an air-assisted fuel injector. This characterization involves four sets of tests: fuel and air flow calibration; instantaneous measurements of fuel and air solenoid signals, internal pressure in the injector, and poppet lift; photographs of the spray; and droplet sizing. The injector poppet was designed to form a spray of 80° included angle. Nitrogen, instead of air, was used to assist the injection of unleaded gasoline into steady, compressed nitrogen at room temperature. The following conditions were used: nominal fuel flow rates of 10, 20, and 30 mm3/injection; spray chamber pressures of 0.1, 0.169, and 0.445 MPa; and nominal injections per minute (IPM) of 1600 and 3000. Results showed a linear increase in total fuel mass supplied to the injector as fuel solenoid pulse width was increased, except at the highest IPM and chamber pressure when the total fuel mass tended to level off.
1990-02-01
Technical Paper
900482
M. C. Leschiutta, J. A. Eng, J. K. Martin
A nonintrusive diagnostic technique has been developed by which dynamic axial piston-position and tilt-angle measurements have been made in a single-cylinder research engine. A laser beam, introduced into the combustion chamber through an optical port in the cylinder head, was reflected by a polished surface on the piston crown. Motion of the reflected beam, carrying with it information on piston position and piston tilt, was monitored by a set of receiving optics. Piston motion was studied as a function of both engine speed and cylinder pressure (i.e., piston loading.) Measured axial piston-position was found to deviate from the theoretical position calculated from the measured crank-shaft position owing to the effects of tilt and piston loading. Furthermore, evidence of piston veer (tilt of the piston in a plane parallel to the axis of the wrist pin) was observed, which had an effect on the accuracy of the axial piston-position measurement.
1990-02-01
Technical Paper
900488
Steven M. Dues, Joseph M. Adams, George A. Shinkle
Knowledge learned through the successful application of millions of knock sensors on automotive engines is reported. An explanation of the basic characteristics of the knock phenomena and their relationship to sensing capabilities is given. Popular conceptions and misconceptions concerned with engine knock and the variables affecting it are examined. Sensing methods are described, with the emphasis being on vibration sensitive devices. Application methodologies and issues are discussed, with a review of potential pitfalls in sensor selection, sensor location, and systemization.
1990-02-01
Technical Paper
900484
G. R. Sleightholme
Abstract The inhomogeneity of the charge in a spark-ignition engine cylinder has been examined by means of a novel fast-response flame ionisation detector. In the experiments presented here propane was used as a fuel, either completely pre-mixed (as a control experiment) or in varying degrees of inhomogeneity, including injection just behind the inlet valve to give a situation similar to that in a gasoline port-injection system. The engine was a single-cylinder Ricardo E6 research engine. The equipment used here provides an insight into the inhomogeneity of the incoming cylinder charge and into the mixing process in the cylinder. The cylinder charge inhomogeneity has been characterised in terms of the average inhomogeneity of the charges, of the cyclic variations therein, and of the cyclic fluctuations in the amount of fuel admitted.
1990-02-01
Technical Paper
900485
Francois Galliot, Wai K. Cheng, Chun-On Cheng, Mark Sztenderowicz, John B. Heywood, Nick Collings
The residual gas fraction prior to ignition at the vicinity of the spark plug in a single cylinder, two-valve spark ignition engine was measured with a fast-response flame ionization hydrocarbon detector. The technique in using such an instrument is reported. The measurements were made as a function of the intake manifold pressure, engine speed and intake/exhaust valve-overlap duration. Both the mean level of the residual fraction and the statistics of the cycle-to-cycle variations were obtained.
1990-02-01
Technical Paper
900486
David Nutton, Robert A. Pinnock
In order to accurately control the ignition and fuelling of a gasoline engine, in the presence of environmental and system variability, it is necessary to measure the effect this variability has on the combustion process and then to initiate control action dependent upon this effect. Various systems have been proposed to gain a more comprehensive combustion measure than today's Lambda sensors can provide, including in-cylinder pressure, ionization probes, wide range exhaust gas oxygen sensors, etc. None of these systems has proven truly practical for volume production either because of the very high sensor cost, the computational load required by the signal processing, or performance limitations. This paper describes the application of in-cylinder optical probes to combustion feedback and control.
1990-02-01
Technical Paper
900431
Francis R. Duffey
: The status of engine coolant specifications is discussed. The differing requirements for coolants for light duty engines and for heavy duty engines, test method development, and future opportunities are among the topics presented.
1990-02-01
Technical Paper
900487
Georg F. Mauer, Robert J. Watts
- Many internal combustion engines are equipped with a vibration damper attached to the front. Excessive thermal loads on the viscous damping element occasionally lead to damper failure, which in turn causes excessive torsional oscillation amplitudes in the crankshaft, and subsequent damage to the engine if the damper failure is not recognized immediately. Two non-contacting magnetic sensors at the engine front and flywheel detect the speed at both locations, and the torsional crankshaft strain. A digital circuit, which includes a microprocessor, samples and processes the raw engine speed speed data. The transducer concept provides for stable operation independent of motor speed and varying ambient temperatures. Experimental data were recorded on an eight-cylinder Diesel engine with and without damper. The measurements, made under steady state operating conditions, show that the speed oscillation amplitudes at the engine front more than double when the damper fails.
1990-02-01
Technical Paper
900429
F. Bolza
Recently there have been moves to reduce costs in the automotive industry. Models have become internationalised and are increasingly shared amongst past competitors. Currency movements have seen countries like Australia emerging as viable exporters of cars and components. Such changes have implications for automotive coolant manufacturers for continuing survival in the global market. Local and overseas standards have often conflicting requirements not satisfied by single formulations. Countries with divergent influences from the US, Japan and Europe, need to develop universally acceptable products and help realisation of truly international specifications and recommended practices.
1990-02-01
Technical Paper
900430
Gert A. Liebold, Laszlo L. Meszaros, Helmut H. Schmidt
Abstracts European automotive coolant technology will be influenced by “Europe 1992” which means free trade and free traffic. Methods to evaluate the demanded quality level of coolants are described. Different chemical approaches to that aim are discussed. Attention is payed to ecological and toxicological aspects. The paper closes with an outlook to further developments. This paper will deal with European coolant technology and the expected influence of “Europe 1992” to this item. Europe 1992 will mean free trade and free traffic between the countries of the European community (EC). EC includes 12 countries with 9 languages, about 320 million people on about 900.000 sguare miles, one quarter the size of the U.S. These 12 countries have a car population of about 130 million units, the car density varies from 6.6 people per car in Portugal to 2.2 people in Germany, as compared with 1.3 people in the U.S.
1990-02-01
Technical Paper
900443
Wolfgang F. Wachter
A heavy duty diesel engine was developed to meet US-EPA 1991 emission standards, and heavy duty diesel transient cycles (HDDTC) were run with different engine versions. Actual engine data such as speed, torque, air mass flow, gaseous emissions, temperatures and the carbon- and HC-fraction of particulate matter were transiently recorded. For each limited pollutant the phases of the HDDTC were identified, where a major contribution to the total cycle emission occurs. Comparing different engine versions, strategies for further reduction of emissions were elaborated. Emphasis was placed on particulate matter.
1990-02-01
Technical Paper
900438
T. Minami, I. Yamaguchi, M. Shintani, K. Tsujimura, T. Suzuki
Two types of high pressure injection equipment, which can produce a pressure of 250MPa, have been developed. One is a hydraulic pressure intensified type, having a “GRADUAL RISE AND SHARP CUT” injection rate pattern. The other is a pressure accumulator type, having a “SQUARE” injection rate pattern. These equipments have been evaluated with a high pressure vessel for analyzing the effect of injection pressure and injection rate upon the characteristics of non-evaporating fuel spray. High speed photography, shadow photography, holography and image analysis techniques were used for these studies. It was found that the fuel injected under high pressure forms finer droplets and produces a leaner mixture. It was also found that several differences exist in the structure of fuel spray between the accumulator type and the pressure intensified type. The reasons for these differences are discussed herein.
1990-02-01
Technical Paper
900437
Yu-Kang Zhou, F. G. Hammitt
With the advent of high-speed, high-ouput diesel engines, cavitation erosion of wet-cylinder liners is one of the most prevalent types of failure and a major problem confronting designers. It has been attributed to many mechanisms by various researchers in different countries. The present paper summarizes the authors' work, reviews published information on this problem, and discusses various contradictory findings. It has been found from vibratory cavitation tests that it is possible to produce conditions leading to erosion of the water-side of diesel engine cylinder liners. Photomicrographs from laboratory vibratory cavitation specimens and eroded liners from diesel engines in the field are compared. It is further confirmed that diesel engine liner erosion is usually due to cavitation erosion, caused, in most cases, by vibration of the liner wall. Liner damage is only a special case of general cavitation damage.
1990-02-01
Technical Paper
900436
John J. Truhan, R. Douglas Hudgens
Cast aluminum alloys 356 and 319 and wrought alloy 3003 were corrosion tested in a commercial (Fleetguard DCA-4) supplemental coolant additive (SCA) package modified by varying the potassium nitrate level. Electrochemical techniques were used to determine the stability of the passive film as a function of nitrate concentration. Cyclic potentiodynamic polarization and cyclic galvanostaircase polarization were the principle techniques used and compared. In the presence of the other inhibitors, the passive film stability did not change as the nitrate concentration varied. The corrosion resistance of each alloy was more dependent on the alloy chemistry with 3003 being the most resistant and 319 being the least. The two electrochemical techniques provided results consistent with each other.
1990-02-01
Technical Paper
900435
R. Douglas Hudgens, W. G. Bugelski
Coolant containing the proper amount of glycol and additives is critical to the reliability and durability of heavy duty diesel engines. Occasional coolant analysis is required in the field to insure that the proper coolant composition is maintained, otherwise severe engine damage can occur. There are several types of coolant test kits currently available in the field as well as commercial coolant analysis services. Some of the test methods used provide information that does not predict or correlate with a coolant's capability to prevent system corrosion and deposit formation. This paper examines the more widely available field coolant analysis methods and documents their strengths and weaknesses. Further, recommendations are made as to acceptable laboratory methods for the analysis of engine coolants.
1990-02-01
Technical Paper
900434
Richard D. Hercamp, R. Douglas Hudgens, Glenn E. Coughenour
Cavitation corrosion of cylinder liners in heavy duty engines can be one of the significant limits in engine operating time between overhauls. In both laboratory and engine dynamometer studies, engine coolants based on propylene glycol (PG) have performed better than similar formulations based on ethylene glycol with regard to cast iron cavitation corrosion. The performance of PG base coolant in all other aspects of coolant use was equivalent or superior to both industry standards and existing ethylene glycol (EG) products designed for use in heavy duty engines. Additionally, propylene glycol is cost competitive, readily available, and less toxic compared to ethylene glycol. A propylene glycol base engine coolant is described which assists the heavy duty user in solving many current problems related to cooling system servicing and engine life.
1990-02-01
Technical Paper
900433
Satoshi Ohkawa, Titose Kawasaki, Kenji Kumagae
A new antifreeze coolant has been developed for the heavy-duty diesel engine. This anti-freeze coolant has better anticorrosion performance than Supplemental Coolant Additives (SCAs) and has longer life than commercial permanent-type coolants. The new antifreeze coolant is composed of ethylene glycol and corrosion inhibitors. In glass ware tests, the new antifreeze coolant showed the best anticorrosion performance in cast iron, aluminum and other metals. The anticavitation pitting property and anti-oxidation property were also tested. In order to evaluate the new antifreeze coolant, a bench engine test procedure has been established. Since the new antifreeze coolant caused light cylinder liner pitting on bench test, antifoaminq property of the coolant was improved. The improved coolant showed excellent performance against cavitation-pitting and aluminum corrosion on engine bench and in the field.
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