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Technical Paper

Wavelet Transform Analysis of Measurements of Engine Combustion Noise

Wavelet transform analysis is capable of revealing aspects of data that other techniques miss such aspects are trends, and discontinuities in higher derivates. This method can often compress or de-noise a signal without any appreciable degradation and it provides accurate information on the localization of energy content in time and frequency [1]. The Wavelet transform method has been applied to the analysis of combustion noise and piston slap in order to identify the effects on the engine structure vibration. The experimental results showed that combustion noise and piston slap were successfully detected from the acceleration signals picked up by external transducers in the outer wall of an in-line, 6 cylinder diesel engine.
Technical Paper

Wavelet Transform applied to Combustion Noise Analysis in High-speed DI Diesel Engines

Traditionally, combustion noise in Diesel engines has been quantified by means of a global noise level determined in many cases through the estimation of the attenuation curve of the block using the traditional discrete Fourier transform technique. In this work, the wavelet transform is used to establish a more reliable correlation between in-cylinder pressure (sources) and noise (effect) during the combustion of a new generation 2 liter DI Diesel engine. Then, in a qualitative sense, the contribution of each source intrinsic to the combustion process is determined for four engine operating conditions and two injection laws. The results have shown high variations in both the in-cylinder pressure and noise power harmonics along the time, which indicates the non-stationary character of this process.
Technical Paper

Ways to Meet Future Emission Standards with Diesel Engine Powered Sport Utility Vehicles (SUV)

The paper reports on the outcome of a still on-going joint-research project with the objective of establishing a demonstrator high speed direct injection (HSDI) diesel engine in a Sport Utility Vehicle (SUV) which allows to exploit the effectiveness of new engine and aftertreatment technologies for reducing exhaust emissions to future levels of US/EPA Tier 2 and Euro 4. This objective should be accomplished in three major steps: (1) reduce NOx by advanced engine technologies (cooled EGR, flexible high pressure common rail fuel injection system, adapted combustion system), (2) reduce particulates by the Continuous Regeneration Trap (CRT), and (3) reduce NOx further by a DeNOx aftertreatment technology. The current paper presents engine and vehicle results on step (1) and (2), and gives an outlook to step (3).
Technical Paper

We've Done the Job — What's It Worth?

The paper covers highlights of SAE activity on emissions control from the early efforts of Campbell and others in the 1930's to the present time. Evidence of substantial involvement in the Los Angeles “smog” composition led to the development of analytical tools for continuous evaluation of exhaust. With these tools and other basic information, it became possible to develop many control devices. Over 20 of these devices have been added as standards have tightened. The negative result has been increasing cost and complexity. The crankcase and evaporative systems have been controlled, but the principal emissions have come from the exhaust, and therefore most of the controls were directed to this source. Combustion within the engine has been the principal area of attention, but when this did not meet the requirements of the existing statues, combustion beyond the exhaust ports became important. Notable contributions to this art were air pumps, afterburners and catalysts.
Technical Paper

Wear Bench Test of Materials Used for Piston Rings and Cylinder Liners of Internal Combustion Engines

Since wear is a not a material property, but a tribological system property, it is of great importance to know the wear, friction and lubrication behavior of materials tested in bench equipment. This work presents reciprocating pin-on-plate bench tests results, with gas nitrided stainless steel pins and gray cast iron plates. The testing conditions were 0.5 and 3.2 Hz frequency, 20 and 600N applied load and 100 and 150 °C. Under these conditions, mild to severe wear transition was observed. It was noticed noise emission changes at wear transition. This noise change could be used to verify wear transition mechanism.
Technical Paper

Wear Mechanisms of Methanol Fueled Engine

The wear mechanisms of the methanol engine were studied using dynamometer tests. Formic acid from methanol combustion mixes with the lubricant oil and attacks the metal surfaces. The iso tacho prorissis method was successfully applied to analyze the formic acid content of the used oil. A large amount of condensed water is also formed by methanol combustion and accelerates the wear. Wear can be effectively reduced by shortening lubricant oil change intervals, by using a special oil and by durable surface treatment of engine parts.
Technical Paper

Wear Mechanisms of Steel Under Boundary Lubrication in Presence of Carbon Black and Graphite Nano-onions Particles

Both carbon blacks and carbon nano-onions nanoparticles have a spheroidal shape and a nested structure. They can be used to simulate the presence of soots in used engine oils. When added to fully formulated fresh engines oils, these two kinds of particles behave very differently. Carbon black particles are highly abrasive causing a lot of wear of steel surfaces and friction increases. At the opposite, the addition of carbon onions in lubricant leads to a reduction of both friction and wear compared to pure base oil. This shows that there is an opportunity to control wear in engines by changing the structure of soots during the combustion process.
Technical Paper

Wear Prediction in Internal Combustion Engine Valve Materials

In internal combustion engine valves, wear often develops at the interface of the valve seat and the insert as a result of the high pressures produced by the combustion process at the moment of the closing event. An alternative to study the wear is by carrying out experimental tests in specific wear testing machines. The main drawback is that they are time consuming and expensive due to the need to carry out many tests for the usually observed scatter in the results. In the area of numerical methods, the wear simulation has been widely developed in the last years because it can solve complicated time consuming problems with general geometries. The aim of this work is to characterize the wear rate coefficients for bi-metallic pairs commonly used in internal combustion engine valves using experimental results and numerical solutions by using the Finite Element Method. Then, a numerical valve model is provided to demonstrate that the numerical and experimental solutions are in agreement.
Technical Paper

Wear Rate Determination for IC Engine Condition Monitoring Results Obtained in an Urban Transport Fleet

This paper is structured into two different parts: Firstly, it describes a methodology to evaluate wear conditions in internal combustion engines in order to go beyond the classical evaluation based on specified wear concentration limits provided by engine manufacturers or commercial oil laboratories. The proposed methodology uses spectrometric wear debris measurement data and typical maintenance data to obtain a more representative parameter of wear condition, defined as “compensated wear rate”, that takes into account particular engine operating conditions affecting wear concentration measurements. Later, an evaluation of this compensated wear rate is carried out using statistical criteria and considering individual engine characteristics such as engine age, type of service, engine metallurgy, environmental conditions of work etc.
Technical Paper

Wear Resistant and Fuel Efficient Ni-Co Based Composite Coating for Engine Cylinder Application

Automobile component particularly the engine cylinder is subjected to continuous wear during the running of the automobile specifically the two wheelers. Aluminium alloys are the material of choice due to their high strength/weight ratio. As aluminium alloys have poor wear and corrosion resistance, a uniform wear resistant composite coating is required on the bore of the internal combustion engine cylinder. There are several methods to produce composite coatings like chemical and physical vapour deposition, plasma spraying, metal infiltration, powder metallurgy etc. Ni-SiC coating commercially known as NIKASIL, is the most commercially used coating in automobile’s/aero IC engines. However, SiC tends to react with the nickel matrix at temperatures above 400 °C forming a brittle nickel silicide which deteriorates the performance of the coating. Also, the synthesis of SiC particles utilizes high energy.
Technical Paper

Wear Study of Coated Heavy Duty Exhaust Valve Systems in a Experimental Test Rig

The exhaust valve system of combustion engines experiences a very complex contact situation of frequent impact involving micro sliding, high and varying temperatures, complex exhaust gas chemistry and possible particulates. The wear rate has to be extremely low, and the individual wearing events operate at a scale that is very demanding to detect. The tribological conditions in the exhaust valve system are expected to become even worse for engines that will follow the future emission regulations. The regulations demand reduced amounts of soot and particles, sulfur compounds, etc., which today act beneficial for the seating surfaces. The reductions are expected to increase the metal-to-metal contact.
Technical Paper

Weight and Cost Reduction — Engine and Engine Components — Converting Castings to Stampings

This paper describes a conceptual development program to demonstrate the weight and cost reduction potential using steel stampings for internal combustion engines and engine components. Various components have been redesigned as steel stampings to replace cast iron or cast aluminum items on a weight and/or cost reduction basis. Designs of a stamped steel engine block, intake and exhaust manifolds, water pump, power steering pump, pulleys, alternator and turbocharger housing are described. Stamped steel versions which have been prototyped and tested are described. A review of current applications and suggested applications of stampings to replace castings concludes the paper.
Technical Paper

Well-to-Wheel Energy Use and Greenhouse Gas Emissions for Various Vehicle Technologies

The well-to-wheel greenhouse gas (GHG) emissions and energy use of selected alternative vehicles are compared to those of a conventional gasoline vehicle. The vehicle technologies investigated are internal combustion engine, hybrid and fuel cell technology. The fuels are assumed to be produced from either crude oil or natural gas. Wherever possible real data has been used. The study shows that hybrid vehicles emit a similar amount of greenhouse gas as fuel cell vehicles. The diesel hybrid uses the least primary energy. The least greenhouse gas emissions are produced by natural gas and hydrogen hybrid and fuel cell vehicles.
Technical Paper

We’ve Done the Job — What’s Next?

Spectacular progress has been made in reducing pollutants from the internal combustion engine. Time and money - a multimillion expenditure - are needed to improve the internal combustion engine so that pollution can be reduced to almost any level desired. To date, medical research does not appear to indicate that much beyond what is being planned in the way of vehicle controls is called for in the foreseeable future.
Technical Paper

What About the Engine?

MR. TAUB predicts that the time for intensive work on the fuel-economy problem, such as has been done recently in England, is near at hand because of the imminence of increased fuel taxation. Tank mileage, he explains, depends on the ability of an engine to utilize lean mixtures- not just lean mixture from the carburetor, but modification of an engine to burn these lean mixtures without interference with flexibility or performance in any way. A study of what happens in the combustion chamber is cited as the major opportunity for engineering improvement in the ability to burn lean mixtures. In his discussion of his work at Vauxhall Motors, Mr. Taub considers wide gaps and their effect on ignition lag, long-reach spark plugs, tappet adjustment, effect of higher compression ratios, variation per cycle, detonation, and means of forecasting combustion roughness.
Technical Paper

What Are the Barriers Against Brake Thermal Efficiency beyond 55% for HD Diesel Engines?

This study focused on the technology integration to aim beyond 60% indicated thermal efficiency (ITE) with a single-cylinder heavy-duty diesel engine as an alternative to achieve 55% brake thermal efficiency (BTE) with multiple-cylinder engines. Technology assessment was initially carried out by means of a simple chart of showing ITE and exhaust heat loss as functions of cooling loss and heat conversion efficiency into indicated work. The proposed compression ratio (28:1), excess air ratio and new ideal thermodynamic cycle were then determined by a simple cycle calculation. Except for peak cylinder pressure constraint for each engine, the technical barriers for further ITE improvement are mainly laid in cooling loss reduction, fuel-air mixture formation improvement, and heat release rate optimization under very high temperature and density conditions with very high compression ratio (smaller cavity volume).
Technical Paper

What Is New in Heat-Treating Methods, Materials, Processes

THE control of grain size has facilitated the development of new steels and modifications in heat-treating processes, Mr. Davis announces. His paper deals with modern progress in the steel mill, the employment of the Carbometer and Turbidimeter, lime-silica ratio and the newer deoxidizers employed to aid steel quality. The internally heated immersion bath has been a distinct advancement in salt-bath hardening and enables longer pots to be practical, he explains. Dry cyaniding with ammonia gas may eventually obsolete cyanides and activated baths, in the opinion of the author. Gas carburizing gradually is supplanting box carburizing, he reports, and many large heat-treating units carburize, quench wash and temper mechanically. Also, a late gas carburizing furnace eliminates the employment of a muffle.
Technical Paper

What's Happened to Secondary Wiring Life?

The deterioration of secondary ignition wiring life on today's internal combustion gasoline engine has created many maintenance problems in the field. The mandatory use of TVRS (resistance wire) has amplified these problems and made them more difficult to solve. The solution does not lie solely with wire design-engine application, engine design, and component selection and location are also important factors. THE LIFE SPAN of the secondary wiring used on gasoline automotive engines dropped dramatically with the introduction of resistance-type wire which is commonly referred to as TVRS wire. The TVRS wire was introduced to suppress ignition interference in accordance with SAE specifications, and to meet the requirement of Public Law 200 passed in October 1951. The TVRS wire was also intended to reduce spark plug electrode erosion. While both of these missions were accomplished, in most cases the wire had a very short life.
Technical Paper

Wheel Power in Urban and Extra-Urban Driving for xEV Design

Electrified powertrains respond to driver demand for vehicle acceleration by producing power through either the electric drive system or an on-board combustion engine or both. In Plug-In Hybrid Vehicles (PHEVs), the powertrain provides the purest form of transportation when responding to driver demand through the electric drive system. We develop a method to size the electric drive system in PHEVs to provide zero emission driving in densely populated urban regions. We use real world data from Europe and calculate instantaneous wheel power during trips. Ray tracing is used to identify the regions where trips occur and the population density of these regions is obtained from an open source dataset published by Eurostat. Regions are categorized by their population density into urban and extra-urban regions. Real world data from these regions is analyzed to determine the wheel power required in urban and extra-urban settings.
Technical Paper

Where is The HSDI Diesel Engine Going?

Thanks to the modern DI diesel's well known features, such as high thermal efficiency, excellent driveability, durability, low operating cost, the market share of diesel passenger cars in Europe has grown from 14% in 1990 to 33% in 2000 and it still continues to grow. However, the foreseeable evolution of exhaust emission legislation gives rise to the question whether the passenger car diesel engine can preserve its undeniable advantages at competitive system cost in the future. The present paper deals with the criteria decisive for market success such as engine performance, speed range and light weight design. Following is an assessment of the current and future technological elements required to meet the standards placed on both fuel economy and exhaust emissions. Based on these analyses development strategies for future passenger car diesel engines are suggested.