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Technical Paper

A 3D-Simulation with Detailed Chemical Kinetics of Combustion and Quenching in an HCCI Engine

2008-06-23
2008-01-1655
A 3D-CFD model with detailed chemical kinetics was developed to investigate the combustion characteristics of HCCI engines, especially those fueled with hydrogen and n-heptane. The effects of changes in some of the key important variables that included compression ratio and chamber surface temperature on the combustion processes were investigated. Particular attention was given, while using a finer 3-D mesh, to the development of combustion within the chamber crevices between the piston top-land and cylinder wall. It is shown that changes in the combustion chamber wall surface temperature values influence greatly the autoignition timing and location of its first occurrence within the chamber. With high chamber wall temperatures, autoignition takes place first at regions near the cylinder wall while with low surface temperatures; autoignition takes place closer to the central region of the mixture charge.
Technical Paper

A 50cc Two-Stroke DI Compression Ignition Engine Fuelled by DME

2008-06-23
2008-01-1535
The low auto-ignition temperature, rapid evaporation and high cetane number of dimethyl ether (DME) enables the use of low-pressure direct injection in compression ignition engines, thus potentially bringing the cost of the injection system down. This in turn holds the promise of bringing CI efficiency to even the smallest engines. A 50cc crankcase scavenged two-stroke CI engine was built based on moped parts. The major alterations were a new cylinder head and a 100 bar DI system using a GDI-type injector. Power is limited by carbon monoxide emission but smoke-free operation and NOx < 200ppm is achieved at all points of operation.
Technical Paper

A 7 -Cylinder IVD Compressor for Automotive Air Conditioning

1989-02-01
890309
A 7-cylinder, wobble plate type, infinitely variable displacement, (IVD), compressor has been developed to meet the following requirements as set forth by the world automotive manufacturers: 1 Wide range of capacity control to eliminate clutch cycling which causes temperature and humidity fluctuations of louver outlet air and unexpected engine load variations 2 Near perfect protection of the evaporator against icing 3 Reliability under all field operating conditions 4 Quiet operation in a compact and lightweight package to suit the new trends in automotive design. A simpler mechanism has been applied to the variable angle cam drive and wobble plate rotation prevention method than with the conventional IVD compressor. The 7-cylinder design, with fewer parts for the piston drive mechanism, enables a quiet compressor of 161.3 cc displacement in a 118 mm diameter casing. An internal control valve is integrated in the center of the valve plate assembly.
Technical Paper

A Basic Study on Reduction of Cylinder Block Vibrations for Small Diesel Cars

2000-03-06
2000-01-0527
The production unit number of small diesel engine cars tends to decline except recreational vehicles in Japanese market in recent years, while the production unit number in Europe market keeps on increasing owing to the merits of the durability and the fuel consumption. The small diesel engines will have to be improved in the near future by solving major problems such as noise and vibration pollution, environmental pollution, improvement in performance of diesel engines, in order to expand the production of the engines. This paper refers to a basic study on the experimental and analytical methods for the reduction of resonant vibration in each vibration mode on some cylinder blocks of small high-speed diesel engines in rated engine speed range. Hammering test method, which is easy and useful for measuring frequency response functions, is carried out in the experiments.
Technical Paper

A Basis for Estimating Mechanical Efficiency and Life of a Diesel Engine from its Size, Load Factor and Piston Speed

2011-09-13
2011-01-2211
Parameters like brake mean effective pressure, mean velocity of the piston, hardness of the wear surface, oil film thickness, and surface areas of critical wear parts are similar for all the diesel engines. The mean piston velocity at the rated speed is nearly the same for all the diesel engines. The mechanical efficiency normalized to an arbitrary brake mean effective pressure (bmep) is dependent on the size of the engine. The engine life seems to be proportional directly to the square of a characteristic dimension namely, cylinder bore of the engine and inversely to speed and load factor for engines varying widely in sizes and ratings.
Technical Paper

A Big Size Rapid Compression Machine for Fundamental Studies of Diesel Combustion

1981-09-01
811004
As a basic tool for fundamental studies on combustion and heat transfer in diesel engines, a new rapid compression machine with a cylinder bore of 200 mm was developed which can realize in it a free diesel flame in a quiescent atmosphere, a diesel flame in a swirl, and a diesel flame impinging on the wall. The piston of this machine is driven by high pressure nitrogen, and its speed is controlled by a sophisticated hydraulic system. This paper describes the details of the mechanism and performances of the machine, and presents some examples of studies conducted with this machine.
Technical Paper

A Biodiesel Mini Baja Vehicle and Student Competition

2008-04-14
2008-01-1293
The SAE Mini Baja® competition is an extremely popular design competition that focuses on the design of an off-road vehicle for performance and cost-of-production. A 2006-07 EPA P3 Phase I grant was awarded to the University of Alabama at Birmingham to convert a vehicle created for the SAE Mini Baja® competition to a biodiesel vehicle. Because of the major size difference in the diesel engine chosen compared to the much smaller gasoline engine, conversion of the Baja vehicle required considerably more effort than expected. While many mechanical aspects of the bio-diesel conversion were more complicated than expected, the students were successful in creating bio-diesel and in modifying important vehicle systems. The students also gained a substantial understanding of the economical and environmental aspects of alternative fuel generation. Through the conversion experience gained at UAB, the rules for a new competition were explored.
Technical Paper

A COHERENCE MODEL FOR PISTON-IMPACT GENERATED NOISE

1979-02-01
790274
An experimental study was conducted to investigate piston-impact generated noise in diesel engines. A coherence model was used to represent the noise generating mechanisms of the engine. The model was applied to an in-line turbo-charged diesel engine. Frequency response functions were measured between the cylinder liner vibration and the engine noise, and between the combustion pressure and the engine noise. The noise coherent with piston impacts was separated from the noise coherent with combustion. Guidelines are presented showing how the results of the coherence model may be used for engine design and noise prediction.
Journal Article

A Carbon Intensity Analysis of Hydrogen Fuel Cell Pathways

2021-03-02
2021-01-0047
A hydrogen economy is an increasingly popular solution to lower global carbon dioxide emissions. Previous research has been focused on the economic conditions necessary for hydrogen to be cost competitive, which tends to neglect the effectiveness of greenhouse gas mitigation for the very solutions proposed. The holistic carbon footprint assessment of hydrogen production, distribution, and utilization methods, otherwise known as “well-to-wheels” carbon intensity, is critical to ensure the new hydrogen strategies proposed are effective in reducing global carbon emissions. When looking at these total carbon intensities, however, there is no single clear consensus regarding the pathway forward. When comparing the two fundamental technologies of steam methane reforming and electrolysis, there are different scenarios where either technology has a “greener” outcome.
Technical Paper

A Case Study for Life Cycle Assessment (LCA) as an Energy Decision Making Tool: The Production of Fuel Ethanol from Various Feedstocks

1998-11-30
982205
Life Cycle Analysis (LCA) considers the key environmental impacts for the entire life cycle of alternative products or processes in order to select the best alternative. An ideal LCA would be an expensive and time consuming process because any product or process typically involves many interacting systems and a considerable amount of data must be analysed for each system. Practical LCA methods approximate the results of an ideal analysis by setting limited analysis boundaries and by accepting some uncertainty in the data values for the systems considered. However, there is no consensus in the LCA field on the correct method of selecting boundaries or on the treatment of data set uncertainty. This paper demonstrates a new method of selecting system boundaries for LCA studies and presents a brief discussion on applying Monte Carlo Analysis to treat the uncertainty questions in LCA.
Technical Paper

A Compact 10 kW Electric Power Range Extender Suitable for Plug-In and Series Hybrid Vehicles

2011-09-11
2011-24-0085
The paper discusses the concept, specification and overall performance of a 10 kW electric power range extender suitable for electric plug-in and series hybrid vehicles, based on a single cylinder, high speed, four stroke internal combustion engine, tested and developed at Istituto Motori CNR of Italy. This unit has been conceived from the beginning as a compact on board recharging system for the mentioned kind of means, and especially for city cars and small commercial vehicles. The paper starts by defining some characteristics, advantages and drawbacks of an electric city car, followed by the criteria adopted to characterize the nominal power of the range extender. Then, the ratio which leaded to the adoption of a single cylinder internal combustion engine is discussed, followed by an explanation of the main design characteristics of the whole unit.
Technical Paper

A Comparative Analysis of Alternative Fuel Infrastructure Requirements

1989-09-01
892065
This paper presents results of an assessment that identifies vehicle technology and fuel distribution system changes and costs associated with providing sufficient alternative fuels to displace one million barrels/day petroleum in the transportation sector in the 1995-2005 timeframe. The paper concludes that the capital cost of developing fuel delivery systems and a sufficient number of vehicles to achieve this displacement will be $22 billion if the alternative fuel is methanol, $36 billion if natural gas, and $288 billion if electricity. The predominant component of these costs is that of the incremental cost of the vehicles.
Technical Paper

A Comparative Analysis of Combustion Process in D.I. Diesel Engine Fueled with Biodiesel and Diesel Fuel

2000-03-06
2000-01-0691
The 1997 Kyoto International Conference Protocol committed industrialized countries to reduce their global emissions of greenhouse gases within the period 2008 2012 by at least 5% with respect to 1990. In view of this and following the European Community directives, the Italian government approved a three-year pilot project to promote the experimental employment of biodiesel. The methyl esters of vegetable oils, known as biodiesel are receiving increasing interest because of their low environmental impact and their potential as an alternative fuel for diesel engines as they would not require any significant modification of existing engines. Consequently, an experimental research program has been developed to evaluate performance and emissions of a Diesel engine fueled with a methyl ester derived from rape seed (Rapeseed Methyl Ester or RME) by changing the composition of the diesel fuel-RME mixture. This program aims to analyze the performance and emissions of a turbocharged D.I.
Technical Paper

A Comparative Analysis of Direct Injection into a Pressurized Chamber Using an Automatic Image Treatment Methodology

2016-10-25
2016-36-0163
A multi-hole direct injection injector was studied by means of image analysis. Methodologies based on an automatic process of cone angle measurement and edge detection were applied for the spray images generated by a 100 bar injection pressure discharged into a pressurized rigid chamber. A criterion based on pixel values was taken to localize the spray edges as angular coordinates and also with x and y position data. The high pixel values were associated with liquid phase while the low pixel values were associated to its absence. Computational codes written in MATLAB environment were used to analyze the numerical matrices associated to the images. Using the written MATLAB codes, a comparison of the effect of atmospheric back pressure, inside the chamber, on the spray pattern, cone angle and spray penetration were evaluated. The chamber was pressurized with 2.5, 5.0, 7.5 and 10 bar of back pressure. The tested fluid injected was EXXSOL D60 for simulating ethanol fuel behavior.
Technical Paper

A Comparative Analysis of Ethanol Versus Gasoline as a Fuel in Production Four-Stroke Cycle Automotive Engines

1995-12-01
952749
This paper presents the findings of a study that compared the fuel efficiency, power, emissions, engine wear and material compatability characteristics of automotive four-stroke cycle engines fueled by E95 (95 % ethyl alcohol and 5% lead free regular gasoline) and 87 pump octane number lead-free gasoline. A group of six senior Automotive Engineering Technology students, conducted the research over a one-year period. Two Mankato State University faculty served as directors for the project. The laboratory facilities at Mankato State University were used for vehicle modification and testing. Two identically equipped 1994 Geo Metros with 1.0 liter, three cylinder, throttle body fuel injected engines were used for this study. After a 6440 km (4000 mile) break-in period, to assure the cars performance characteristics were equal, one of the vehicles was converted to run on E95.
Journal Article

A Comparative Analysis on Engine Performance of a Conventional Diesel Fuel and 10% Biodiesel Blends Produced from Coconut Oils

2015-09-06
2015-24-2489
This paper presents engine performance and emissions of coconut oil-derived 10% biodiesel blends in petroleum diesel demonstrating simultaneous reduction of smoke and NOx emissions and increased brake power. The experiments were performed in a single-cylinder version of a light-duty diesel engine for three different fuels including a conventional diesel fuel and two B10 fuels of chemical-catalyst-based methyl-ester biodiesel (B10mc) and biological-catalyst-based ethyl-ester biodiesel (B10eb). The engine tests were conducted at fixed speed of 2000 rpm and injection pressure of 130 MPa. In addition to the fuel variation, the injection timing and rate of exhaust gas recirculation (EGR) were also varied because they impact the combustion and thus the efficiency and emissions significantly.
Technical Paper

A Comparative Analysis on the Spray Penetration of Ethanol, Gasoline and Iso-Octane Fuel in a Spark-Ignition Direct-Injection Engine

2014-04-01
2014-01-1413
This study aims to clarify the spray development of ethanol, gasoline and iso-octane fuel, delivered by a multi-hole injector and spark-ignition direct-injection (SIDI) fuelling system. The focus is on how fuel properties impact temporal and spatial evolution of sprays at realistic ambient conditions. Two optical facilities were used: (1) a constant-flow spray chamber simulating cold-start conditions and (2) a single-cylinder SIDI engine running at normal, warmed-up operating conditions. In these optical facilities, high-speed Mie-scattering imaging is performed to measure penetrations of spray plumes at various injection pressures of 4, 7, 11 and 15 MPa. The results show that the effect of fuel type on the tip penetration length of the sprays depends on the injection conditions and the level of fuel jet atomisation and droplet breakup.
Technical Paper

A Comparative Assessment of Current Gasohol Fuel Economy Data

1980-08-01
800889
The use of ethyl alcohol as a motor fuel blending agent has been promoted as method for reducing the consumption of petroleum. A mixture of 90 volume percent unleaded regular gasoline and 10 volume percent anhydrous ethyl alcohol, popularly known as “Gasohol,” has probably received the most current interest. This report is a summary and analysis of all currently available comparative Gasohol fuel consumption data. Usable data were eventually obtained from sixteen (16) different Gasohol test programs conducted by various public and private organizations. Ten (10) of these programs were conducted with chassis dynamometers, and the remaining six (6) were road tests of varying duration. Data from each or the test programs were subjected to a statistical analysis to determine whether the results were significant. Finally, all of the data were combined in order to determine an overall mean Gasohol fuel economy effect.
Technical Paper

A Comparative Assessment of Tailpipe Emission Characteristics on Diesel Engine Using Nanofluid with R-EGR Setup

2020-09-25
2020-28-0442
The current research over the use of nano additive as a distinguishable thing on decelerating hazardous diesel engine emissions. The experiment was conducted with biofuel, there is no significance of engine modifications for using the biofuel. The surplus amount of oxygen integrated within the biofuel can able to generate higher combustion rate relatively it produces more NOx, the NOx burden can be reduced with the help of REGR (reformed exhaust gas recirculation). The reforming of exhaust gases causes the measurable generation of smoke, CO and HC. In order to reduce the formation of above emissions, the affordable and sustainable alternate identified from the present research, by citronella biofuel with 100ppm Cobalt Chromite nano additive. The scrutinized output enumerates that the substantial reduction in HC, CO, and BSFC with elevated EGT (exhaust gas temperature) achieved by CBN-REGR than the typical usage of the traditional CB-EGR system.
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