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Engine dynamometer testing of homogeneous charge, spark ignition lean burn engines fueled by natural gas, hydrogen/natural gas blends and neat hydrogen was conducted to determine if NOx emissions from blended fuel operation can be reduced below those generated from natural gas operation, approaching those due to a 100% hydrogen fueled engine. The preliminary tests were conducted at the University of Central Florida/Florida Solar Energy Center on an eight cylinder automotive engine. The results indicate that the hydrogen/natural gas fuel has the potential of meeting highly restrictive NOx levels. Sandia National Laboratories conducted follow-on, comparative tests using a single cylinder research engine. The Sandia results indicate that the proposed CARB EZEV standard for NOx can be met without exhaust gas aftertreatment using a 30% hydrogen (by volume) / 70% natural gas blend fuel in a constant speed/power, hybrid vehicle application which achieves 60 MPG gasoline equivalent efficiency.

A two-dimensional technique for the quantitative determination of the fuel-air ratio in hydrogen fuelled engines has been developed. The technique is based on the spontaneous Raman scattering of the hydrogen molecules (Stokes Q-branch) and the simultaneous measurement of the pressure inside the combustion chamber. From these data the local partial pressure of the hydrogen and, therefore, the fuel-air ratio can be calculated. This method was applied in a single cylinder direct injection research engine in order to prove the applicability of this technique under real engine conditions. The measurements inside the side chamber of the engine show a fast mixing process of the compressed air and the injected hydrogen (6 MPa injection pressure) independent of the injection timing.

There is currently a large effort in industry to make natural gas a viable alternative fuel for internal combustion engines. While the use of natural gas offers several advantages such as reduced emissions and potentially higher efficiency, it also has some inherent difficulties. Among these is the challenge of producing a consistently homogeneous air/fuel mixture while retaining the advantages which accompany modern, multi-point, fuel injection systems. The purpose of the research described here is to investigate the in-cylinder mixture formation process in a port injected natural gas fueled engine. Planar laser-induced fluorescence has been used to produce qualitative air fuel ratio maps in the engine cylinder, in selected planes, throughout the intake and compression strokes. The process consists of impinging a sheet of ultraviolet laser light on various planes parallel to, and normal to, the cylinder axis.

The hydrogen assisted jet ignition system (HAJI) replaces the spark plug of an Otto cycle engine and consists of a very small pre-chamber into which a hydrogen injector and spark plug are installed. The HAJI system allows stable combustion of very lean main-chamber hydrocarbon mixtures, leading to improved thermal efficiency and very much reduced NOx emissions. The current investigation focuses on the application of HAJI to a modern pent-roof, four valve per cylinder automotive engine. The development of a new hydrogen injection system and HAJI pre-chamber based on proprietary gasoline and diesel injectors is described. Results from injector and engine performance testing are presented in detail.

The effect of engine operating conditions on the formation of combustion chamber deposits has been studied by varying the driving cycle used in a series of vehicle tests aimed at measuring the CCD formation tendencies of different multifunctional fuel detergent additives. It was found that at higher engine temperatures it is not possible to easily differentiate the performance of different additives and that low load and low speed conditions should be chosen when testing additives for CCD control. The data obtained suggest that there is a direct correlation between the decomposition temperature of additive components as measured by thermogravimetric analysis (TGA) and their CCD formation tendencies. Of the various carrier fluids surveyed, materials based on alkyl oxides seem to perform the best in controlling CCD formation.

This paper describes a 30 vehicle test conducted to evaluate the performance of a new gasoline additive technology. The technology consistently demonstrates an ability to control octane requirement increase of automotive engines, and even effect a reduction, under standard dynamometer stand conditions. The objective of this work was to determine if a beneficial influence, relative to unadditized base fuel, on the octane requirement of a broad fleet of typical customer vehicles could be observed. Included in this evaluation is an assessment of both octane requirement increase control (ORIC) and octane requirement reduction (ORR). Additionally, data regarding inlet valve deposits (IVD), combustion chamber deposits (CCD), emissions, and lubricant properties are included.

In response to industry demands for a method to qualify fuels for their intake valve deposit (IVD) forming tendencies, the Coordinating Research Council (CRC) has developed an engine dynamometer test procedure. In Phase I, the 2.3L Ford engine was chosen as the focus test engine in comparison testing with two other high volume U.S. manufactured engines.1* A two-mode dynamometer test was developed in Phases II-A & II-B and shown to discriminate among the test fuels at a 95% confidence level.2 In Phase III, both an interlaboratory study (ILS) of the two-mode dynamometer test and a vehicle fleet study were performed. The ILS was conducted to determine the repeatability and reproducibility of the test procedure and also to fulfill requirements for consideration of the test as an American Society for Testing and Materials (ASTM) standard.

The paper discusses objectives, approaches and results of the development of a pilot fuel injection system (FIS) for a dedicated, compression ignition, high-speed, heavy duty natural gas/diesel engine. The performance of the pilot FIS is crucial for the success of a dual fuel concept. The Servojet electro-hydraulic, accumulator type fuel system was chosen for the pilot fuel injection. An alternative pilot FIS based on the “water hammer” (WH) effect was also considered. The modifications to a stock 17 min injector is described. Three different types of pilot injector nozzle were investigated: standard Valve Covered Orifice (VCO), modified minisac and new designed, unthrottled pintle. Preliminary results from engine tests proved that the optimum pilot fuel quantity is the minimum quantity. Based on that finding, the pilot FIS design was further optimized.

In this paper we address the design and performance of a mini-SHED (Sealed Housing Evaporative Determination) system prototype for measurement of hydrocarbon permeation of automotive fuel system components. It is PC-based, and is built around ‘National Instruments’ data acquisition boards and LABVIEW© software package. It is capable of running the 24-hour diurnal cycle, as well as steady state tests at user-selected temperatures. A flame ionization detector, FID, is used to measure the hydrocarbon emission of the component in the SHED as a function of temperature and/or time. The mini-SHED was tested using propane shot tests and the amount of emission was determined accurately within a +/-4% suggested tolerance. The system has been designed to run unattended once the user has responded to a few prompts. Data is taken and logged once an hour for the diurnal test cycle, and at a user-selected frequency in hours for the steady state test.

This paper intends to analyze the simultaneous impact of speed and acceleration on exhaust pollutant emissions. For this purpose, actual driving recording were used. Kinematic sequences were randomly selected amongst the recorded data, in order to constitute a representative set of driving conditions. For each sequence, average levels of speed and positive acceleration were calculated. Instantaneous and integrated pollutant emissions were calculated using an existing emission model, developed for calculating pollutant emissions and fuel consumption as functions of instantaneous speed and acceleration. This model is based on instantaneous emission measurements on a chassis dynamometer using actual driving cycles, over a sample of 150 European cars. Emissions of CO, CO2, HC, NOx were analyzed considering the average speed and positive acceleration, for different categories of vehicles Diesel, conventional and catalyst vehicles.

Two pickup trucks, both with 5.9 L, turbocharged and intercooled, direct injection diesel engines, were tested for regulated emissions at the Los Angeles County Metropolitan Transit Authority Emissions Testing Facility, one in 1994 and the other in 1995. Emissions testing was conducted using the Dynamometer Driving Schedule for Heavy Duty Vehicles (Code of Federal Regulations 40, Part 86, Appendix 1, Cycle D). Emissions data generated included total hydrocarbons (HC), carbon monoxide (CO), carbon dioxide (CO2), oxides of nitrogen (NOx) and particulate matter (PM). All tests were with a chassis dynamometer capable of transient testing. This paper presents an analysis and comparison of the emissions tests for each year as well as a comparison between years. Differences in emissions found between years are reported. Test methods, procedures and the experimental designs are discussed. The test data presented in this report represents the emissions of three biodiesel fuel blends.

A new non-black (colorless) heavy load grease, having superior anti-seizure property and multi-purpose performance for construction machines, has been developed. The main components of the non-black heavy load grease are apertinent viscosity base oil, lithium complex soap and a unique non-black solid lubricant (phosphate glass). The weld load of the new non-black heavy load grease is 4900 N by the four ball EP tester. This value is almost the same as that of 60% molybdenum disulfide paste. The several type grease samples, mixed with 1 % clay dust, were evaluated by the four ball EP tester. The multi-purpose EP lithium grease lost the antiwear property and the MoS2 grease maintained antiwear property. The new non-black heavy load grease shows the best antiwear property against the clay dust. Furthermore, a number of laboratory tests have been conducted to prove the multi-purpose performance for construction machines.

All automotive gear oils must satisfy a series of standard industry or Original Equipment Manufacturer (OEM) tests. These usually include bench, axle dynamometer, and field tests. However, product development testing must extend beyond satisfying standard test protocols. This is especially true as increased emphasis is placed on extending oil drain intervals and increasing equipment life in the face of greater performance demands through new heavy-duty vehicle designs. End-users ultimately benefit from extended oil drain intervals and increased equipment life. However, the effort to achieve both initiatives will prove successful only through careful development and selection of the proper performance additives and base fluids. Also, a broad focus must be maintained to satisfy all lubricant requirements. These requirements build on a solid base of standard features and include new features that stretch the current envelope of gear oil performance.

In gear lubricant applications, fluid film thickness is a critical parameter for ensuring adequate gear protection. Modern gear lubricants are specially formulated to protect gears from wear and fatigue under a wide variety of conditions. However, if the fluid film breaks down, the lubricant is subjected to extremes of pressure and temperature that will diminish its ability to protect gear surfaces. This can result in reduced equipment life. Increased emphasis on fuel economy, extended fluid life, and other performance parameters, have resulted in increased use of wide-span multigrade gear lubricants, which may contain relatively high levels of polymer compared to the more traditional SAE 80W-90 and SAE 85W-140 grades. SAE 75W-90 and SAE 80W-140 grade gear lubricants are common examples.

The objective of the research project was the investigation of lubricant film formation in elastohydrodynamic contacts for oils of different origin (paraffinic, naphthenic, polyalphaolefin) and various types of VI-improvers (polymethacrylate, olefin copolymer, styrene butadiene copolymer). An essential part of the research was to find out whether VI-improvers maintain their thickening effect under contact conditions of high pressure (p=10,000 bar) and temperature (ϑ=50-90 °C), high shear rate (γ̇=106 s-1) and short contact time, all these conditions occurring simultaneously. A twin disk machine was used to determine values of film thickness in a line contact. For these measurements, an electrical capacitance method was used. In addition to a thermal viscosity loss, high shear rate γ̇ leads for VI improved oils to temporary viscosity loss and thus reduced film thickness. Additional permanent viscosity loss due to shear thinning reduces measured film thickness further.

A test facility was constructed at University College London to study fuel spray structure within a gasoline direct injection engine. The facility consisted of a single cylinder research engine with extensive optical access and a novel video imaging and analysis system. The engine used an experimental prototype 4-valve cylinder head with direct in-cylinder high pressure fuel injection, provided by a major automotive manufacturer. The fuel spray was illuminated using a pulsed copper-vapour laser. Results are presented that illustrate the spray behaviour within the fired research engine. A laser light sheet provided an insight into the inner spray cone behaviour.

A new type direct-injection stratified-charge combustion system for gasoline engines is developed by the authors. In the system, gasoline is directly injected into a cylinder near the end of compression stroke by a nozzle with the injection holes unequally spaced on its tip. The angles among sprays in the vicinity of spark plug are small, and become larger downstream along the direction of air swirl motion. Therefore the circularly concentration stratification form rich to lean of air-fuel mixture is mechanically realized to ensure the reliable ignition and smooth flame propagation in the inhomogeneous mixture after sparking. The selection of main parameters of the system, the performance and the combustion characteristics of the engine after optimization of those parameters are introduced in detail in this paper.

Increasing interest in gasoline engine emissions has focused attention on the fuel compositional and emissions effects that govern NOx conversion over the catalyst. This study reports the transient effects of individual species emissions and catalyst conversions on NOx conversion made using Fourier Transform Infra Red (FTIR) spectroscopy of the engine-out and tailpipe emissions (regulated and speciated) during the testing of a catalyst equipped gasoline vehicle run on multi-component model fuels over the standard European cycle. FTIR measurements confirm that transient NO conversion is directly correlated with that of CH4, especially within the Urban Drive Cycle (EUDC). Other hydrocarbon species do not govern the transient variability in NO conversion. This vehicle maintained ϕ≤ 1.0 practically throughout the EUDC and consequently no correlation was seen between transient NO conversion and equivalence ratio.

The main factors influencing the development of engine oils for the future are environmental protection, resource utilization and customer satisfaction. Improving engine oil no longer means just providing adequate durability but also maximizing fuel efficiency, minimizing detrimental effects on emission systems and maximizing useful life. Opportunities for improvements in these areas, discussed in detail in this paper, will be considered by ILSAC (International Lubricant Standardization and Approval Committee formed by the American Automobile Manufacturers Association, AAMA, and Japan Automobile Manufacturers Association, JAMA) in developing the ILSAC GF-3 standard to be introduced around the year 2000.

Recently, we reported the development of a new reduced chemical kinetic model for predicting reactivity and autoignition behavior of primary reference fuels in a motored research engine. The predicted oxidation behavior (ignition delay, preignition heat release, and evolution of key chemical species) is in fairly good agreement with experiments. In addition, the model reproduced the experimentally observed dependence of overall reactivity on charge density and manifold inlet conditions. This paper reports our initial effort to apply this new reduced chemical kinetic model to other fuels. Specifically, the model was tested using neat n-butane and n-butane/iso-butane blends (10, 20, and 48 percent by volume iso-butane) under skip fired conditions. The only adjustments made in the model were to the fuel specific rate parameters of the RO2· isomerization reaction, the reaction of aldehydes with OH·, and the reaction forming cyclic ethers.