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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

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

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

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

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

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.
Technical Paper

GV Heated Cabin Window - Design, Testing, and Certification

2000-05-09
2000-01-1668
Due to the increased flight envelope of GV aircraft and the industry-wide problems with crazing of structural acrylic transparencies, a re-design of the Gulfstream cabin windows was undertaken for the GV. The primary goals of this effort were to develop a cabin window that remained condensation free in all operating conditions, had improved service life, retained the size and shape of the classic Gulfstream cabin windows, and met all current FAA and JAA certification requirements. Cost and weight, as well as structural interchangeability with earlier Gulfstream aircraft, were also important issues. These goals were met during a significant design and testing effort undertaken both at Gulfstream and with the vendor, PPG Industries Inc. Aircraft Products. The resulting design, currently installed in all GV aircraft, retains the large field of view that is synonymous with all Gulfstream models while incorporating a number of newer technologies and improvements.
Technical Paper

Estimating the Rate of Technology Adoption for Cockpit Weather Information Systems

2000-05-09
2000-01-1662
This paper summarizes the results of a survey to estimate the market penetration rate of cockpit weather information systems in five aviation markets: transport, commuter, general aviation, business, and rotorcraft. It begins by describing the general features that survey respondents identified as necessary characteristics for the market success of cockpit weather systems. Next the paper analyzes the financial benefit of cockpit weather systems for each market segment. Decision reversal tables and Monte Carlo simulation are employed to examine the sensitivity of the financial results to changes in the cost and savings elements. Finally, estimates for adoption rates in the five aviation market segments are presented.
Technical Paper

Real-Time On-Board Measurement of Mass Emission of NOx, Fuel Consumption, Road Load, and Engine Output for Diesel Vehicles

2000-03-06
2000-01-1141
Regulatory compliance measurements for vehicle emissions are generally performed in well equipped test facilities using chassis dynamometers that simulate on-road conditions. There is also a requirement for obtaining accurate information from vehicles as they operate on the road. An on-board system has been developed to measure real-time mass emission of NOx, fuel consumption, road load, and engine output. The system consists of a dedicated data recorder and a variety of sensors that measure air-to-fuel ratios, NOx concentrations, intake air flow rates, and ambient temperature, pressure and humidity. The system can be placed on the passenger seat and operate without external power. This paper describes in detail the configuration and signal processing techniques used by the on-board measurement system. The authors explain the methods and algorithms used to obtain (1) real-time mass emission of NOx, (2) real-time fuel consumption, (3) road load, and (4) engine output.
Technical Paper

Development of Low Density Glass Mat Thermoplastic Composites for Headliner Applications

2000-03-06
2000-01-1129
Glass-mat-thermoplastic (GMT) composites are frequently used in structural applications in the automotive industry. Typically, these materials are flow molded in a compression press and weigh 4000 - 4900 g / m2. In this paper, we present the development of low-density (700 -2000 g / m2), long-fiber GMT composites for applications in headliner and other interior components. The new thermoplastic headliner materials offer several advantages over existing headliner materials, including low weight and cost; high rigidity at elevated temperatures and high humidity; faster cycle time; recyclability; design flexibility; a more environmentally friendly production method; and reduction of raw material inventory compared to existing processes. In this paper, we will discuss the mechanical and acoustical properties of this new headliner material and compare it with current headliner material substrates.
Technical Paper

Development of a Closed Loop, Full Scale Automotive Climatic Wind Tunnel

2000-03-06
2000-01-1375
A closed loop full-scale automotive climatic wind tunnel is described. The tunnel simulates wind and rain as well as several road conditions. It generates under controlled heat loading, wind speeds of up to 50kmh with different approach boundary conditions, rains from drizzle to cloudburst and road inclines up to 15° in any direction. The design and optimization process of the tunnel functions is outlined and examples of its use in vehicle development are given. The size constraint and the need for a compact design are important features of the tunnel. The tunnel provides an important test bed for close scrutiny of the relationship between rain ingress, vehicle speed, road condition, heat loading and vehicle geometry. The tunnel can also be used to study vehicle thermal management, vehicle thermal comfort, engine cold starting, and wipers efficiency in sever cold weather.
Technical Paper

Correlation Between the Measured Flame Surface Density and Turbulence Parameters in Turbulent Premixed Flames

2000-03-06
2000-01-1383
Recent findings on the characteristics of flame surface density are introduced for turbulent premixed combustion in typical operating conditions of SI engines. The maximum flame surface density tends to show linear dependence on the K -factor defined as a function of the integral length scale and . The flame surface density shows an asymmetric profile in the space with the peak location correlated in terms of the dimensionless parameter, NB, which represents the degree of gradient or counter-gradient diffusion by turbulence. The effects of the K -factor and NB are discussed in the wrinkled flamelet and corrugated flamelet regime respectively. The flame surface density increases at a higher ambient pressure due to decrease in the laminar flame speed and the length scales of flame wrinkling. Comments are made on the turbulent stretch and turbulent flux terms in the Σ -equation in modeling combustion of an SI engine.
Technical Paper

INVESTIGATION ON COMBUSTION BEHAVIOR OF EXTREMELY LEAN MIXTURES IN A CLOSED BOMB LIKE A GASOLINE ENGINE

2000-01-15
2000-01-1423
From the viewpoint of energy saving and air pollution prevention which are needed for development of internal combustion engines, experiments have been carried out to elucidate the true combustion bahavior of extremely lean mixtures in a closed bomb by using the microgravity techniques. Microgravity conditions established in a falling assembly enables the flame propagation and the measurement in lean-limit states. The oscillatory nature of flame propgation appeared in very lean mixtures of propane-air may be explained in term of Lewis number which is less than unity. Turbulence is shown to be ineffective in enhanching the burning velocities and indeed may cause extinction in very lean mixtures.
Technical Paper

The Effects of Driveability on Emissions in European Gasoline Vehicles

2000-06-19
2000-01-1884
Fuel volatility and vehicle characteristics have long been recognised as important parameters influencing the exhaust emissions and the driveability of gasoline vehicles. Limits on volatility are specified in a number of world-wide / national fuel specifications and, in addition, many Oil Companies monitor driveability performance to ensure customer satisfaction. However, the relationship between driveability and exhaust emissions is relatively little explored. A study was carried out to simultaneously measure driveability and exhaust emissions in a fleet of 10 European gasoline vehicles. The vehicles were all equipped with three-way catalysts and single or multi-point fuel injection. The test procedure and driving cycle used were based on the European Cold Weather Driveability test method.
Technical Paper

Optimization of Natural Gas Combustion in Spark-Ignited Engines Through Manipulation of Intake-Flow Configuration

2000-06-19
2000-01-1948
An investigation was performed to try to quantify the relative importance of large-scale mixing and turbulence in a multi-valve spark-ignited automotive engine converted to use natural gas fuel. The role of mixing was examined by comparing single-point versus multi-point combustion performance at several operating conditions. The fuel-air mixture passed through a static mixer prior to entering the intake manifold in the single point case. This configuration was assumed to produce a well-mixed charge entering the combustion chamber. The fuel was delivered just upstream of the intake port in the multi-point configuration. The charge was assumed to be stratified in this case. The results showed a significant degradation in combustion stability and maximum power but little difference in ignition delay and fully-developed burn duration using multi-point injection. The relative role of turbulence was examined by altering the intake-flow configuration to create three levels of inlet swirl.
Technical Paper

Do Turbulent Premixed Flame Fronts in Spark-Ignition Engines Behave Like Passive Surfaces?

2000-06-19
2000-01-1942
A widely held belief in the combustion community is that the chemical and hydrodynamic structure of a stretched laminar premixed flame can be preserved in a turbulent flow field over a range of conditions collectively known as the flamelet regime, and the homogeneous charge spark-ignition engine combustion falls within the domain of this regime. The major assumption in the laminar flamelet concept as applied to the turbulent premixed flames is that the flame front behaves as a constant-property passive scalar surface, and an increase in the wrinkled flame surface area with increasing turbulence intensity is the dominant mechanism for the observed flame velocity enhancement. The two approaches that have been recently used for estimating a measure of the wrinkled flame surface area in spark-ignition engines and other premixed flames are the flame surface density concept and fractal geometry.
Technical Paper

A Research in the Cause of Simultaneous Reduction of NOx • SFC on HONDA CVCC SI Engine

2000-06-19
2000-01-1938
(1) Through the accumulation of many researches during 1974∼94 done by the authors [8∼12,15], as like temperature measurement or the calculation of it by normal flame propagation model, it was clarified the difficulty of explanation for the captioned theme shown in the title by the conventional past concept. (2) To conquer these issued problems a new hypothesis in which the burned gas jet from pre-chamber has mixed with premixed gas in the main-chamber and acted as same as internal EGR was proposed. (3) The calculated result of this hypothesis coincided qualitatively and quantitatively with the measured flame temperature and others that the appropriateness of this was verified. (4) The result of the state in combustion at A/F=18 has been in 7% of low oxygen concentration, 2350°K of high temperature and strong turbulent condition. (5) This paper suggests a new guideline for the target to lower NOx, lower fuel consumption by low oxygen, high temperature and strong turbulent combustion.
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