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A set of additives was selected to improve the durability of the physical-chemical and biological characteristics of mineral diesel and its blend with biodiesel. Two biodiesels were used: soybean (SME) and rapeseed (RME). Both physical-chemical properties and fuel dispersion of fuel blends and their mixtures with additives were measured that could have effects on the combustion process in diesel engines. The dispersion of the fuel is affected by the injection nozzle integrity, influencing the capacity of the fuel to vaporize, while the modification of the fuel molecular structure can cause changes in combustion reaction. A 7 hole Common Rail (CR) 2nd generation injector, 136 ?m in diameter, was used at 80 MPa and 1.0 ms injection pressure and duration, respectively. The injection rate was determined using the Bosch's Method, while the fuel dispersion was measured by analyzing the images of spray evolving in an optical accessible quiescent vessel. The results showed that the additives have a great influence on the stability of the blends. Adding the biocide "P", antioxidant "AN" and pour point depressant "D", an increase of the oxidation stability of 390 % of the B20SME samples compared to B20 without additives. For B20SME containing "P", "AS" and "D", the oxidation stability increased of 810%. The injection rate data showed that a slight reduction in the rate of injections (9.91% for Diesel B5RME, 8.13% relative to B20RME and 12.84% relative to B20SME) was registered when additives were used. Finally, the inclusion of the additives did not produce particular variations on the fuel spray tip penetration.

This paper clarifies aggressivity reduction approach for MPV, Multi-Purpose Vehicles, derived from large passenger vehicles toward small passenger vehicles. The effects of aggressivity-reducing approach were measured through full-frontal rigid barrier crash simulations with TRL aluminum honeycomb by Finite Element Method. The front-end structures of large vehicles studied in this paper based on this aggressivity reduction approach show good front-end homogeneity and low average height of force. The structures were also found to effectively reduce aggressivity toward small vehicles by car-to-car simulation. However, there are some cases where the effect was influenced by overlap ratios. From this result, overlap ratio is considered to be one of the important factors to improve compatibility performance.

Combusiton of pine pyrolysis oil droplets was studied at different pressures up to a maximum of 60 bar in a single-droplet combustion chamber. Oil droplets, with diameters between 400 \gmm and 120 \gmm were suspended to a thermocouple of to a quartz fiber. Their behavior was followed by means of high-speed digital imaging based on a shadowgraph scheme. About two thousands of frames were collected during every test with acquisition speed between 400 and 4000 frames/s. Droplets were easy to ignite at normal as well as at high pressure. Increasing the pressure the intensity of swelling phenomena, undergone by droplets, decreased and completely disappeared at pressures higher than 20 bar. However, bubbling and foaming were always observed. Liquid-phase pyrolysis and the formation of cenospheres as combustion residual were observed under all the pressure conditions.

A burning process in a combustion chamber of an internal combustion engine is very important to know the maximum temperature of the gases, the speed of combustion, the ignition delay time of fuel and air mixture exact moment at which ignition will occur. The automobilist industry has invested considerable amounts of resources in numerical modeling and simulations in order to obtain relevant information about the processes in the combustion chamber and then extract the maximum engine performance control the emission of pollutants and formulate new fuels. This study aimed to general construction and instrumentation of a shock tube for measuring shock wave. As specific objective was determined reaction rate and ignition delay time of diesel and ethanol doped with different levels of additive enhancer cetane number. The results are compared with the delays measured for the ignition diesel and biodiesel.

Acetone-Butanol-Ethanol (ABE), an intermediate product in the ABE fermentation process for producing bio-butanol, is considered a promising alternative fuel because it not only preserves the advantages of oxygenated fuel which typically emit less pollutants compared to conventional diesel, but also lowers the cost of fuel recovery for each individual component during the fermentation. With the development of advanced ABE fermentation technology, the volumetric percentage of acetone, butanol and ethanol in the bio-solvents can be precisely controlled. In this respect, it is desirable to estimate the performance of different ABE blends to determine the best blend and optimize the production process accordingly.

In the present study, ethanol was added in lower proportions to non-edible vegetable oil “Schleichera oleosa” or “Kusum”, to evaluate various performance and emission characteristics of a single cylinder; diesel engine. For engine's trial, four samples were prepared with 5%, 10%, 15% and 20% ethanol in kusum oil (v/v) and the blends were named as E5K95, E10K90, E15K85 and E20K80 respectively. Neat Kusum oil was named as K100. The results indicated that brake thermal efficiency (BTE) was found to increase with increase in volume fraction of ethanol in the kusum oil. E5K95, E10K90, E15K85 and E20K80 test fuels exhibited maximum BTE of 25.4%, 26.4%, 27.4% and 27.7% respectively as compared to 23.6% exhibited by the neat Kusum oil. Similarly, full load brake specific energy consumption (BSEC) decreased from 16.3MJ/kWh in case of neat Kusum oil to 15.1MJ/kWh for E20K80 with an almost linear reduction pattern with increased ethanol composition in the test fuel. Full load carbon monoxide emissions were found to be 0.18% volume for neat Kusum oil which was reduced to 0.1% for E20K80. Similarly, smoke emissions and unburnt hydrocarbons were also found to be reduced by a margin of 7-12% compared to the K100 operation. However, E5K95, E10K90, E15K85 and E20K80 test fuels exhibited 779, 890, 860 and 877 ppm each of NO x emissions as compared to 795 ppm exhibited by the neat Kusum oil.

Forthcoming on-highway 2005/2007 European and North American emission regulations will require modern diesel engines to be equipped with Diesel Particulate Filters (DPF) capable of trapping up to 99% of the exhaust particulate matter. Since diesel particulates (soot) accumulate in the filter over time, the overall system needs to be regenerated by attaining the ignition temperature of soot, which in the presence of oxygen is >600 °C. Catalyzed DPFs regenerate at temperatures as low as ∼300 °C. One of the major issues facing OEMs, aftertreatment system manufacturers, and lubricant formulators is the potential effects of the lubricant-derived ash deposits and their impact on a pressure increase across filters, as well as overall filter performance and its service characteristics. In the present study, several lubricant-formulating additive variables, metal detergent type, antiwear additive (ZDP) type and level, the presence of boron as well as the effect of noble metal concentration in catalyzed DPF were examined. The paper explores ramifications of these formulation variables, especially the effects of lubricant chemistry, on DPF balance point temperature, ash deposits distribution and recovery. Findings identify the impact of lubricant derived species on soot combustion, ash type and presence of volatile components within the filter deposits.

Increased environmental awareness and depletion of fossil fuel resources are driving industry to develop alternative fuels that are environmentally more acceptable. Vegetable oils are potential alternative fuels. Vegetable oils in India are produced from numerous oilseed crops. While all vegetable oils have high energy content, most require some processing to ensure safe usage in internal combustion engines. Most detrimental properties of oils are its high viscosity, low volatility and polyunsaturated character. The most widely used method is to convert vegetable oils into biodiesel. Biodiesel fuels are primary esters, which are produced by transesterifcation of vegetable oils. Several vegetable oil esters have been investigated so far in different parts of the world and found suitable to be used in diesel engines. In present investigation, methyl esters of some non-edible vegetable oils of Indian origin (castor, linseed and ricebran) are prepared and their properties have been evaluated. The effect of temperature on the viscosity of vegetable oils and their esters was studied. Viscosity of vegetable oils drastically decreases after transesterification. Flash point and specific gravity of neat ricebran and linseed oil and their esters were also evaluated in this investigation. Introduction Increased environmental concerns, tougher clean air standards, increasing prices and uncertainties concerning petroleum availability necessitate the search for a viable alternative fuel, which is more environment friendly, hence vegetable fuel studies have become prominent among various potential alternatives. The idea of using vegetable oils as fuel for diesel engine is not new. When Rudolf diesel first invented t he diesel engine, he demonstrated it at the 1900 world exhibition in Paris, employing peanut oil and said “The use of vegetable oils for engine fuels may seem insignificant today, but such oils may become in course of time as important as petroleum and the coal tar products of the present time” [1]. In the 1930’s and 1940’s, vegetable oils were used as diesel fuels from time to time, but usually only in emergency situations. Recently, because of increase in crude oil prices, limited resources of fossil fuels and environmental concerns, there has been a renewed focus on vegetable oils and animal fats to make biodiesel fuels. Biodiesel is biodegradable, non-toxic and essentially free from sulphur. It is renewable and can be produced from agriculture & plant resources. While short-term tests are positive, long-term usage of neat vegetable oils or their blends with diesel leads to various engine problems such as injector coking, ring sticking, injector deposits etc. [2,3]. High viscosity, low volatility and a tendency to polymerize within the cylinder are the root cause of many problems associated with direct usage of these oils as fuels [2]. The process of transesterification yields vegetable oil esters, which have shown promise as alternative diesel fuel as a result of improved viscosity & volatility characteristics. Several researchers investigate the different vegetable oil esters [3-7] and found esters comparable to diesel fuel. Muniyappa et. al., optimized the transesterification process for Soyabean oil, [3] . Freedman et. al. investigated the effect of various parameters on vegetable oil yield [4]. Several researchers transesterified the vegetable oils and found that properties are quite comparable to mineral diesel and performance and emission characteristics of CI engines using biodiesel in different proportion as a blend with mineral diesel improves [5-10]. Agarwal et.al. developed linseed oil methyl esters and found it comparable to diesel with improved emission characteristics compared to diesel [5,6]. Physical wear of various vital parts, injector coking, carbon deposits etc. were found to be substantially lower in case of 20% biodiesel fuelled engines [11]. The objective of this study is to investigate the effect of transesterifcation on the viscosity and other properties of non-edible vegetable oils of Indian origin and to evaluate the effect of temperature on the viscosity of neat vegetable oil and their methyl esters. Detailed results on the viscosity and other properties of oils and their esters are presented in this paper. Composition of Vegetable Oils Petroleum diesel fuel is a complex mixture of hydrocarbons with carbon atoms ranging between 12-18, whereas vegetable oils are mixture of organic compounds ranging from simple straight chain compound to complex structure of proteins and fat-soluble vitamins and are commonly referred as triglycerides. Vegetable oils are usually triglycerides, generally with number of branched chains of different length, and have structural notation as shown.

This paper describes the simultaneous reduction of nitrogen oxides (NOx) and particulate matter (PM) in a modern light-duty diesel engine under high exhaust gas recirculation (EGR) levels. Simultaneous reduction of NOx and PM emissions was observed under lean conditions at several low to moderate load conditions using two different approaches. The first approach utilizes a throttle to increase EGR rate beyond the maximum rate possible with sole use of the EGR valve for a particular engine condition. The second approach does not use a throttle, but rather uses a combination of EGR and manipulation of injection parameters. A significant reduction in particulate matter size and concentration was observed corresponding to the reduction in particulate mass. This PM reduction was accompanied by a significant shift in the heat release profile. In addition, there were significant cylinder-to-cylinder variations in particulate matter characteristics, gaseous emissions, and heat release. A fuel penalty is associated with operating in the low NOx and low PM regime when there are no modifications to the injection strategy. Preliminary experiments indicate that the penalty can be eliminated or reduced to a few percent while still maintaining a significant reduction in NOx and PM. An improved understanding of this combustion regime will lead to improved EGR utilization for lowering the performance requirements of post-combustion emissions controls.