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Technical Paper

Multifunctional Glasses for Automotive

1996-04-01
91A109
The windows of a vehicle have to satisfy the following driver and passenger needs concerning visibility and climate perception both related to active safety: transparency, reluctance, dazzling, glare and diffused light (scattering). All functions are related to visibility and so to the optics of glazing, solar control, deicing, defogging, demisting. The task of material science is to find the multifunctional glasses solving simultaneously problems of visibility, safety and comfort. Particular kind of glasses, colored, wired, coated, electrochromic, liquid crystal, photochromic can be already considered solutions which can operate passively or actively. The example of passive solar control and active heatable coated glasses is shown as a possible practical multifunctional glass very soon.
Technical Paper

Manufacture of Automotive Components By Semi-Liquid Forming Process

1996-04-01
91A113
Semi-liquid forming process, applied to pressure die-casting, permits to obtain low cost components with high qualitative characteristics and adequate mechanical performances. The technology is based on the employment of material with globular microstructure (flow-cast alloys) obtained subjecting a metal alloy at the time of solidification to an elevated shear rate. Such microstructure permits the accomplishment of conventional forming processes at temperatures in solidification range. The particular fluid-dynamic properties of the semi-liquid slurry and the lower injection temperature allow to obtain casting with improved soundness, without need of impregnation, and to extend die life. The present work describes the Weber (Magneti Marelli) activity of the process industrialization and some applications for the manufacture of automotive components.
Technical Paper

Correlation of Bending Strength and Errors of Helical Gear

1988-03-01
871223
CORRELATION OF BENDING STRENGTH AND ERRORS OF HELICAL GEAR has not been clarified sufficiently even now. As the investigation by using only experimental method is not sufficient and so the analytical method of obtaining gear bending strength has been developed by one of the authors. Hence, the correlation of bending strength and errors, especially in the aspect of the direction of pressure angle error and tooth trace error, is clarified by this analytical method which was verified by some experiments. And by further investigations, it is confirmed that the helical gear is tougher against the negative pressure angle error, and the fine module gear is sensitive against the errors.
Technical Paper

Tire/Pavement Interaction Noise Source Identification Using Multi-Planar Nearfield Acoustical Holography

1999-05-17
1999-01-1733
In this study, multi-planar Nearfield Acoustical Holography (NAH) is used to investigate noise radiated from the front, side and rear areas of single tires on a two-wheel trailer. Contributions to the radiated noise from the leading edge, trailing edge, and sidewall of the tire are identified. Two tires - an experimental monopitch tire and a production passenger car tire - are evaluated on a smooth asphalt pavement at 58 km/hr. From the measured complex pressure, acoustic intensity is reconstructed on three planes surrounding the tire using modified NAH procedures. Additionally, sound power levels are presented in tabulated and spectra forms. Tire noise generating mechanisms are inferred based on the results.
Technical Paper

Squeak Studies on Material Pairs

1999-05-17
1999-01-1727
Advancements in the area of noise and vibration control have succeeded in quieting the vehicle to the point that previously obscure squeak and rattles must now be addressed. One possible way to decrease the squeak levels is by judicious selection of the material friction pairs. The squeak levels produced by a given material friction pair are a function of a number of test conditions like interference, temperature, humidity and excitation frequency. This paper experimentally studies the dependence of squeak levels on these factors. Understanding the relationship between squeak and test conditions will guide the selection of materials and help us to carefully select the test conditions for squeak evaluations. It will also result in cost reductions to otherwise numerous and expensive squeak parameter testing.
Technical Paper

The Effects of Retained Fluid and Humidity on the Evacuation of Critical Vehicle Systems

1999-05-10
1999-01-1630
In automotive assembly facilities worldwide, many critical vehicle systems such as brakes, power steering, radiator, and air conditioning require the appropriate fluid to function. In order to insure that these critical vehicle systems receive the correct amount of properly treated fluid, automotive manufacturers employ a method called Evacuation and Fill. Due to their closed-loop design, many critical vehicle systems must be first exposed to vacuum prior to being flooded with fluid. Only after the evacuation and fill process is complete will the critical vehicle system be able to perform as specified. It has long been thought, but never proven, that humidity and entrenched fluid were major hindrances to the Evacuation and Fill process. Consequently, Ford Motor Company Advanced Manufacturing Technology Development, Sandalwood Enterprises, Kettering University, and Dominion Tool & Die conducted a detailed project on this subject.
Technical Paper

Transfer Matrix Approach to the Estimation of the Fundamental Acoustical Properties of Noise Control Materials

1999-05-17
1999-01-1667
A new method for evaluating the acoustical properties of porous materials is described here. To implement the procedure, a two-microphone standing wave tube was modified to include: a new sample holder; a section that accommodated a second pair of microphones downstream of the sample holder; and an approximately anechoic termination. A four-point sound pressure method was then used to estimate the two-by-two transfer matrix of the material. The transfer matrix can then be used to determine the wave number and characteristic impedance of the material. The procedure has been used to estimate the acoustical properties of two glass fiber materials.
Technical Paper

Acoustical Advantages of a New Polypropylene Absorbing Material

1999-05-17
1999-01-1669
Sound absorption is one way to control noise in automotive passenger compartments. Fibrous or porous materials absorb sound in a cavity by dissipating energy associated with a propagating sound wave. The objective of this study was to evaluate the acoustic performance of a cotton fiber absorbing material in comparison to a new polypropylene fibrous material, called ECOSORB ®. The acoustical evaluation was done using measurements of material properties along with sound pressure level from road testing of a fully-assembled vehicle. The new polypropylene fibrous material showed significant advantages over the cotton fiber materials in material properties testing and also in-vehicle measurements. In addition to the performance benefits, the polypropylene absorber provided weight savings over the cotton fiber material.
Technical Paper

Reconstruction of the Cylinder Pressure from Vibration Measurements for Prediction of Exhaust and Noise Emissions in Ethanol Engines

1999-05-17
1999-01-1658
There are growing demands for condition monitoring of IC engines, and therefore any method in order to improve the performance of the engines ought to be evaluated. This paper proposes a new approach for the prediction and optimisation of noise and exhaust emissions in IC engines. The idea is to reconstruct the cylinder pressure from vibration measurements on the engine surface by using the complex cepstrum method [3, 4]. The reconstructed cylinder pressure is further used as input in Multivariate models, based on cylinder pressure, for estimating noise and exhaust emissions. This paper demonstrates the applicability of the method for modelling of noise and exhaust emissions
Technical Paper

Effect of High Squish Combustion Chamber on Simultaneous Reduction of NOx and Particulate from a Direct-Injection Diesel Engine

1999-05-03
1999-01-1502
In this study it is tried to reduce NOx and particulate emissions simultaneously in a direct injection diesel engine based on the concept of two-stage combustion. At initial combustion stage, NOx emission is reduced with fuel rich combustion. At diffusion combustion stage, particulate emission is reduced with high turbulence combustion. The high squish combustion chamber with reduced throat diameter is used to realize two-stage combustion. This combustion chamber is designed to produce strong squish that causes high turbulence. When throat diameter of the high squish combustion chamber is reduced to some extent, simultaneous reduction of NOx and particulate emissions is achieved with less deterioration of fuel consumption at retarded injection timing. Further reduction of NOx emission is realized by reducing the cavity volume of the high squish combustion chamber. Analysis by endoscopic high speed photography and CFD calculation describes the experimental results.
Technical Paper

The Autoignition Behavior of Surrogate Diesel Fuel Mixtures and the Chemical Effects of 2-Ethylhexyl Nitrate (2-EHN) Cetane Improver

1999-05-03
1999-01-1504
The oxidation of surrogate diesel fuels composed of mixtures of three pure hydrocarbons with and without their cetane numbers chemically enhanced using 2-ethylhexyl nitrate (2-EHN) is studied in a variable pressure flow reactor over a temperature range 500 - 900 K, at 12.5 atmospheres and a fixed reaction time of 1.8 sec. Changes in both low temperature, intermediate temperature, and hot ignition chemical kinetic behavior are noted with changes in the fuel cetane number. Differences appear in the product distribution and in heat release generated in the low and intermediate temperature regimes as cetane number is increased. A chemically enhanced cetane fuel shows nearly identical oxidation characteristics to those obtained using pure fuel blends to produce the enhanced cetane value. The decomposition chemistry of 2-EHN was also studied. Pyrolysis data of 10% 2-EHN in n-heptane and toluene are reported.
Technical Paper

A Non-Averaging Method of Determining the Rheological Properties of Traction Fluids

1999-05-03
1999-01-1518
Traction machines have been frequently used to study the rheological properties of lubricants in elasto-hydrodynamic lubrication (EHL) contacts. Fundamental properties are inferred from EHL traction measurements based on the average pressures and temperatures in the contact. This average approach leads to uncertainty in the accuracy of the results due to the highly nonlinear response of fluid rheological behavior to both pressure and temperature. A non-averaging method is developed in this paper to determine the elastic and plastic properties of traction fluids operating in EHL contacts at small slide-to-roll ratios. A precision line-contact traction rig is used to measure the EHL traction at a given oil temperature and Hertz pressure. By choosing a sensible pressure-property expression, the parameters of the expression can be determined through the initial slope and peak traction coefficient of the traction measurements.
Technical Paper

Neural Network-Based Diesel Engine Emissions Prediction Using In-Cylinder Combustion Pressure

1999-05-03
1999-01-1532
This paper explores the feasibility of using in-cylinder pressure-based variables to predict gaseous exhaust emissions levels from a Navistar T444 direct injection diesel engine through the use of neural networks. The networks were trained using in-cylinder pressure derived variables generated at steady state conditions over a wide speed and load test matrix. The networks were then validated on previously “unseen” real-time data obtained from the Federal Test Procedure cycle through the use of a high speed digital signal processor data acquisition system. Once fully trained, the DSP-based system developed in this work allows the real-time prediction of NOX and CO2 emissions from this engine on a cycle-by-cycle basis without requiring emissions measurement.
Technical Paper

Heating Aircraft Reciprocating Engines

1999-04-20
1999-01-1568
Aircraft engines need preheating to be able to start without damage in cold weather. It is possible to do this efficiently by placing a small amount of heat in the proper places. An installed electric system is very convenient and easy to use. A good design will be light weight and energy efficient. Corrosion in engines that operate in cold weather can be reduced or eliminated by the right preheater design and the proper operation of the engine. Some designs of preheater systems aggravate other problems. A certain amount of caution is needed in selecting the system. The unit should be specifically matched to the aircraft and engine.
Technical Paper

Aviation Weather Information Systems Research and Development

1999-04-20
1999-01-1579
President Clinton announced in February 1997 a national goal to reduce the fatal accident rate for aviation by 80% within ten years. Weather continues to be identified as a causal factor in about 30% of all aviation accidents. An Aviation Weather Information Distribution and Presentation project has been established within the National Aeronautics and Space Administration’s Aviation Safety Program to develop technologies that will provide accurate, timely and intuitive information to pilots, dispatchers, and air traffic controllers to enable the detection and avoidance of atmospheric hazards. This project, described herein, addresses the weather information needs of general, corporate, regional, and transport aircraft operators.
Technical Paper

Activities of the Federal Aviation Administration’s Aviation Weather Research Program

1999-04-20
1999-01-1578
Weather is a major cause of aircraft accidents and incidents and the single largest contributor to air traffic system delays. Through improvements in the knowledge of current weather conditions and reliable forecasts, the Federal Aviation Administration (FAA) can improve aviation safety, increase system capacity, and enhance flight planning and fuel efficiency. The FAA has established an Aviation Weather Research (AWR) program to address specific requirements for weather support to aviation by providing the capability to generate more accurate and accessible weather observations, warnings, and forecasts and also by increasing the scientific understanding of atmospheric processes that spawn aviation weather hazards. The goal of AWR is to provide meteorological research that leads to the satisfaction of specific aviation weather requirements.
Technical Paper

Effects of Fuel Properties on Combustion and Emission Characteristics of a Direct-Injection Diesel Engine

2000-06-19
2000-01-1851
This study investigates the effects of fuel properties on combustion characteristics and emissions such as NOx, smoke, THC and particulates in a direct-injection diesel engine. Fuel properties, such as cetane number and aromatic content, are varied independently in the experiments to separate their effects. The engine tests are carried out at steady operation with changed load, injection timing and injection pressure. The results show that reducing cetane number results in the increase of NOx and decrease of particulate emission at high load. This is because the low cetane number fuel has the long ignition delay and causes the high maximum heat release rate and the short combustion duration. However, high THC emission is produced at low load for the low cetane number fuel.
Technical Paper

Multi-Dimensional Modeling of Ignition, Combustion and Nitric Oxide Formation in Direct Injection Natural Gas Engines

2000-06-19
2000-01-1839
The heat release and pollutant formation processes in a direct injection natural gas engine are studied by coupling detailed chemistry with a multi-dimensional reactive flow code. A detailed kinetic mechanism consisting of 22 species and 104 elementary reactions is chosen by comparing ignition delay predictions with measurements in a combustion bomb. The ignition model is then coupled with a turbulent combustion model and extended Zeldovich kinetics to simulate heat release and nitric oxide production in a direct injection engine. Parametric studies are conducted to investigate the effect of engine operating conditions which include speed, load, injection timing and level of boost. It is shown that use of detailed chemistry is extremely important to predict the correct ignition delay period as engine operating conditions change. Use of both time and crank angle as the independent variable reveals interesting details of the heat release process as a function of engine speed.
Technical Paper

Performance Development of the First European Heavy Duty Diesel Engine Equipped with Full Electronic High Injection Pressure Common Rail System

2000-06-19
2000-01-1821
Over the last few years, Renault VI has gained an important knowledge in low emissions combustion optimization using the high injection pressure Common Rail system. A completely new six cylinder in-line DCI 11 engine has been designed with this full electronic injection system for EURO3 truck applications. The engine performance has been optimized to reach low fuel consumption and low emissions, while keeping customer utilization in mind. After a short view on the general features of the new engine, the highly flexible injection system is presented as well as its potential to control fuel injection timing, fuel quantity and pressure with multiple injections, independently of engine speed and load. The development process is described, covering the swirl design with two inlet ports per cylinder, the injector and combustion bowl geometry match and the injection data optimization.
Technical Paper

Development of the Sequence IVA Valve Train Wear Lubricant Test: Part 1

2000-06-19
2000-01-1820
The ASTM Sequence VE test evaluates lubricant performance for controlling sludge deposits and minimizing overhead camshaft lobe wear. ILSAC asked JAMA to develop a new valve train wear replacement test since the Sequence VE test engine hardware will become obsolete in the year 2000. JAMA submitted the JASO specification M 328-951) KA24E valve train wear test. This first report presents the results of technical studies conducted when JASO M 328-95 was reviewed and the ASTM standardized version of the KA24E test (the Sequence IVA) was proposed. The cam wear mechanism was studied with the goal of improving reproducibility and repeatability. Engine torque was specified to stabilize the NOx concentration in blow-by, which improved test precision. Additionally, the specifications for induction air humidity and temperature, oil temperature control, and test fuel composition were modified when the ASTM version of the KA24E test was proposed.
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