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Technical Paper

Unregulated and Regulated Emissions from Biodiesel Fuelled CRDI SUV Engine

2015-04-14
2015-01-0889
Use of biodiesel from non-edible vegetable oil as an alternative fuel to mineral diesel is attractive economically and environmentally. Diesel engines emit several harmful gaseous emissions and some of them are regulated worldwide, while countless others are not regulated. These unregulated species are associated with severe health hazards. Karanja biodiesel is a popular alternate fuel in South Asia and various governments are considering its large-scale implementation. Therefore it is important to study the possible adverse impact of this new alternate fuel. In this study, unregulated and regulated emissions were measured at varying engine speeds (1500, 2500 and 3500 rpm) for various engine loads (0%, 20%, 40%, 60%, 80% and 100% rated load) using 20% Karanja biodiesel blend (KB20) and diesel in a 4-cylinder 2.2L common rail direct injection (CRDI) sports utility vehicle (SUV) engine.
Technical Paper

Transient Spray Characteristics of Air Assisted Fuel Injection

2015-04-14
2015-01-0920
Gasoline direct injection (GDI) technology is already in use in four wheeler applications owing to the additional benefits in terms of better combustion and fuel economy. The air-assisted in-cylinder injection is the emerging technology for gasoline engines which works with low pressure injection systems unlike gasoline direct injection (GDI) system. GDI systems use high pressure fuel injection, which provides better combustion and reduced fuel consumption. It envisages small droplet size and low penetration rate which will reduce wall wetting and hydrocarbon emissions. This study is concerned with a CFD analysis of an air-assisted injection system to evaluate mixture spray characteristics. For the analysis, the air injector fitted onto a constant volume chamber (CVC) maintained at uniform pressure is considered. The analysis is carried out for various CVC pressures, mixture injection durations and fuel quantities so as to understand the effect on mixture spray characteristics.
Journal Article

Tomographic Particle Image Velocimetry for Flow Analysis in a Single Cylinder Optical Engine

2015-04-14
2015-01-0599
Better understanding of flow phenomena inside the combustion chamber of a diesel engine and accurate measurement of flow parameters is necessary for engine optimization i.e. enhancing power output, fuel economy improvement and emissions control. Airflow structures developed inside the engine combustion chamber significantly influence the air-fuel mixing. In this study, in-cylinder air flow characteristics of a motored, four-valve diesel engine were investigated using time-resolved high-speed Tomographic Particle Imaging Velocimetry (PIV). Single cylinder optical engine provides full optical access of combustion chamber through a transparent cylinder and flat transparent piston top. Experiments were performed in different vertical planes at different engine speeds during the intake and compression stroke under motoring condition. For visualization of air flow pattern, graphite particles were used for flow seeding.
Technical Paper

The Influence of High-Octane Fuel Blends on the Performance of a Two-Stroke SI Engine with Knock-Limited-Compression Ratio

1994-10-01
941863
The use of alcohol-gasoline blends enables the favorable features of alcohols to be utilized in spark ignition (SI) engines while avoiding the shortcomings of their application as straight fuels. Eucalyptus and orange oils possess high octane values and are also good potential alternative fuels for SI engines. The high octane value of these fuels can enhance the octane value of the fuel when it is blended with low-octane gasoline. In the present work, 20 percent by volume of orange oil, eucalyptus oil, methanol and ethanol were blended separately with gasoline, and the performance, combustion and exhaust emission characteristics were evaluated at two different compression ratios. The phase separation problems arising from the alcohol-gasoline blends were minimized by adding eucalyptus oil as a co-solvent. Test results indicate that the compression ratio can be raised from 7.4 to 9 without any detrimental effect, due to the higher octane rating of the fuel blends.
Technical Paper

Studies on Performance and Exhaust Emissions of a CI Engine Operating on Diesel and Diesel Biodiesel Blends at Different Injection Pressures and Injection Timings

2007-04-16
2007-01-0613
The effect of variation in injection pressure and Injection timing on the performance and exhaust emission characteristics of a direct injection, naturally aspirated Diesel engine operating on Diesel and Diesel-Biodiesel Blends were studied. A three-way factorial design consisting of four levels of injection pressure (150,210, 265,320 bar), four levels of injection timing (19° btdc, 21.5° btdc, 26° btdc, and 30.5° btdc) and five different fuel types (D100, B10, B20, B40, and B60) were employed in this test. The experimental analysis shows that when operating with Linseed Oil Methyl Ester-Diesel blends, we could increase the injection pressure by about 25% over the normal value of 20MPa. The engine performance and exhaust emission characteristics of the engine operating on the ester fuels at advanced injection timing were better than when operating at increased injection pressure.
Technical Paper

Spark-Assisted Alcohol Operation in a Low Heat Rejection Engine

1995-02-01
950059
This work demonstrates how the performance of a standard spark-assisted alcohol engine can be improved by using the Low Heat Rejection (LHR ) concept. The improved combustion is attained by better using the greater heat energy in the combustion chamber of a LHR engine - in this case for the faster vaporisation and better mixing of the alcohol fuels. For this program the LHR engine used has a single cylinder diesel and alcohols sued as sole fuels were ethanol and methanol. For spark assistance an extended electrode spark plug was used and location and projection were optimised for best results. These configurations were evaluated for performance and emissions with and without LHR implementation. The results show that the engine with LHR, ethanol fuel and spark assistance has the highest brake thermal efficiency with the lowest emissions.
Technical Paper

Spark Ignition Producer Gas Engine and Dedicated Compressed Natural Gas Engine - Technology Development and Experimental Performance Optimisation

1999-10-25
1999-01-3515
In the present study, a 17 kW, stationary, direct- injection diesel engine has been converted to operate it as a gas engine using producer-gas and compressed natural gas (CNG) as the fuels on two different operational modes called SIPGE (Spark Ignition Producer Gas Engine) and DCNGE (Dedicated Compressed Natural Gas Engine). The engine before conversion, was run on two other modes of operation, namely, diesel mode using only diesel and producer-gas-diesel-dual-fuel mode with diesel used for pilot ignition. The base data generated on diesel mode was used for performance comparison under other modes to ascertain the fuel flexibility. A technology development and optimisation followed by performance confirmation are the three features of this study. The exercise of conversion to SIPGE is a success since comparable power and efficiency could be developed. DCNGE operation also yielded comparable power with higher efficiency, which establishes the fuel flexibility of the converted machine.
Technical Paper

Spark Assisted Diesel Operation in a Low Compression Ratio Low Heat Rejection Engine

1992-02-01
920545
In the present work, investigations were carried out on a single cylinder, low compression ratio, spark-assisted low heat rejection D.I diesel engine. An extended electrode spark plug was used. Performance and emission tests on the engine were carried out with diesel fuel at two compression ratios, 10.5 and 12.5. In each case the engine was tested as a normal engine as well as a low heat rejection engine. The test results show that the low compression ratio spark assisted diesel engine operates very smoothly due to the low peak pressure and low rate of pressure rise. The low heat rejection spark assisted diesel engine gave an improved performance and reduced emissions compared to the normal baseline diesel engine.
Technical Paper

Reducing NO in a Biodiesel Fueled Compression Ignition Engine - An Experimental Study

2015-09-06
2015-24-2483
The replacement of fossil diesel with neat biodiesel in a compression ignition engine has advantage in lowering unburned hydrocarbon, carbon monoxide and smoke emissions. However, the injection advance experienced with biodiesel fuel with respect to diesel injection setting increases oxides of nitrogen emission. In this study, the biodiesel-NO control is attempted using charge and fuel modification strategies with retarded injection timing. The experiments are performed at maximum torque speed and higher loads viz. from 60% up to full load conditions maintaining same power between diesel and biodiesel while retarding the timing of injection by 3 deg. crank angle. The charge and fuel modifications are done by recycling 5% by volume of exhaust gas to the fresh charge and 10% by volume of methanol to Karanja biodiesel.
Technical Paper

Performance of Thin-Ceramic-Coated Combustion Chamber with Gasoline and Methanol as Fuels in a Two-Stroke SI Engine

1994-10-01
941911
The performance of a conventional, carbureted, two-stroke spark-ignition (SI) engine can be improved by providing moderate thermal insulation in the combustion chamber. This will help to improve the vaporization characteristics in particular at part load and medium loads with gasoline fuel and high-latent-heat fuels such as methanol. In the present investigation, the combustion chamber surface was coated with a 0.5-mm thickness of partially stabilized zirconia, and experiments were carried out in a single-cylinder, two-stroke SI engine with gasoline and methanol as fuels. Test results indicate that with gasoline as a fuel, the thin ceramic-coated combustion chamber improves the part load to medium load operation considerably, but it affects the performance at higher speeds and at higher loads to the extent of knock and loss of brake power by about 18%. However, with methanol as a fuel, the performance is better under most of the operating range and free from knock.
Technical Paper

Performance Evaluation of a Small Agricultural Engine Operated on Dual Fuel (Diesel + Natural Gas) System

1995-09-01
951777
Diesel has been used extensively as fuel for small agricultural engines in India. As natural gas is available in abundance, lot of interest is shown to substitute gas for diesel in these engines either partially or fully. Natural gas has a high Octane rating and hence to replace diesel fully, major irreversible changes in the diesel engine is required. However, in the dual fuel (diesel + gas) system a large percentage of diesel substitution is possible by the addition of the components of the conversion system. A simple dual fuel system has been developed indigenously for this study. Engine tests with dual fuel gas system have been conducted on a single cylinder diesel engine. These results show that the performance of the engine with dual fuel system can almost match that of standard diesel engine.
Technical Paper

Noise, Vibrations and Combustion Investigations of Preheated Jatropha Oil in a Single Cylinder Genset Engine

2015-04-14
2015-01-1668
High viscosity of vegetable oil causes ignition problems when used in compression ignition engines. There is a need to reduce the viscosity before using it as engine fuel. Preheating and pre-treating of vegetable oils using waste heat of exhaust gases is one of the techniques, which reduces the viscosity and makes it possible to use it as alternate fuel for some niche applications, without requiring major modifications in the engine hardware. Several applications such as decentralized power generation, agricultural engines, and water pumping engines, can use vegetable oils as an alternative fuel. In present investigation, performance, combustion, and emission characteristics of an engine using preheated 20% blend of Jatropha oil with mineral diesel (J20) has been evaluated at a constant speed (1500 rpm) in a single cylinder four stroke direct injection diesel engine.
Technical Paper

Near Nozzle Flow and Atomization Characteristics of Biodiesel Fuels

2017-10-08
2017-01-2327
Fuel atomization and air-fuel mixing processes play a dominant role on engine performance and emission characteristics in a direct injection compression ignition engine. Understanding of microscopic spray characteristics is essential to predict combustion phenomena. The present work investigated near nozzle flow and atomization characteristics of biodiesel fuels in a constant volume chamber. Waste cooking oil, Jatropha, and Karanja biodiesels were applied and the results were compared with those of conventional diesel fuel. The tested fuels were injected by a solenoid injector with a common-rail injection system. A high-speed camera with a long distance microscopic lens was utilized to capture the near nozzle flow. Meanwhile, Sauter mean diameter (SMD) was measured by a phase Doppler particle analyzer to compare atomization characteristics.
Technical Paper

Investigations on the Design and Performance of Two Types of Hot Surface Ignition Engines

1992-09-01
921632
Use of methanol and ethanol in conventional diesel engines is associated with problems on account of the high self ignition temperature of these fuels. The Hot Surface Ignition (HSI) method wherein a part of the injected fuel is made to touch an electrically heated hot surface for ignition, is an effective way of utilizing these fuels in conventional diesel engines. In the present work two types of HSI engines, one using a large ceramic base and the other using a conventional glowplug were developed. These engines were tested with methanol, M.spirit (about 90 % methanol and 10 % ethanol) and diesel. The results of performance, fuel economy emissions and combustion parameters including heat release rates for these fuels with both the types of HSI engines are presented. Diesel engines are commonly used as primemovers in the mass transportation and agricultural sectors because of their high brake thermal efficiency and reliability.
Technical Paper

Experimental and Modeling Investigation of NO Formation Mechanism for Biodiesel and Its Blend with Methanol

2019-04-02
2019-01-0217
Biodiesel makes an attractive option to replace fossil diesel owing to its applicability in diesel engines without major modifications. An increase in NO emissions with biodiesel compared to diesel is a major concern for its wider use. Blending alcohols, such as methanol, with biodiesel is a potential remedy to mitigate NO formation, as suggested by experiments. However, computational investigations studying the effect of biodiesel-methanol blends on NO formation are scarce. A combined experimental and computational approach is adopted here to investigate the NO formation mechanism with neat biodiesel and biodiesel-methanol blend fueled light duty diesel engine. Firstly, a new compact kinetic model is utilized consisting of oxidation reactions for methyl butanoate and n-dodecane as a surrogate for biodiesel. A surrogate is defined to represent biodiesel based on a combined property and functional group based approach.
Technical Paper

Experimental Investigations on the Combustion of Ethanol in a Low Heat Rejection Engine Using Different Methods

1993-03-01
930931
As alternate fuels, ethyl and methyl alcohols stand out because of the feasibility of producing them in bulk from plentifully available raw materials. In the present work, ethanol is used as the only fuel, in the standard and Low Heat Rejection(LHR) diesel engines by adopting three different methods. In the first method, ethanol as the sole fuel was used in the LHR engine with normal metal glowplug and in the second method spark plug assistance was used to initiate combustion. In the third method, ethanol was used as the sole fuel in a LHR engine and a ceramic glow plug was used to initiate combustion. The engine was tested for performance and emissions for the above three methods of 100% ethanol operation in both the standard and LHR diesel engine and the results are compared. The spark plug assisted ethanol operation in the LHR engine gave the highest brake thermal efficiency and the lowest emissions.
Technical Paper

Experimental Investigations on Three Different Methods of Using 100% Methanol in a Low Heat Rejection Engine

1992-02-01
920197
As alternate fuels, ethyl and methyl alcohols stand out because of the feasibility of producing them in bulk from plentifully available raw materials. In the present work, methanol is used as the only fuel, in a Low Heat Rejection(LHR) engine by adapting three different methods. In the first method, methanol as the sole fuel was used in the LHR engine with a ceramic glowplug and in the second spark plug assistance was used to initiate combustion of the injected methanol. In the third method, methanol was used as the sole fuel in a LHR engine by a new method in which part of the methanol fuel was inducted through a heated inlet manifold using a carburetor and another part of methanol (with 1% castor oil for lubrication) was injected through the normal injector. With inducted methanol air charge temperature at 70 C and above the engine operated smoothly.
Technical Paper

Experimental Investigation of Non-Edible Vegetable Oil Operation in a LHR Diesel Engine for Improved Performance

1993-10-01
932846
The main objective of the present research work is to utilise the higher amounts of exhaust energy of the LHR engines. Three vegetable oils(neem oil, rice bran oil and karanji oil) were tested in the low heat rejection engine. An electrical heater was used to heat the thick vegetable oils or the air and the results were studied. the electrical heater energy was correlated with the energy available in the exhaust of the LHR engine, so that the electrical heater can be replaced by a heat exchanger in the actual engine. The three vegetable oils, without heating, indicated a lower brake thermal efficiency of 1-4% when compared with the standard diesel engine. When these thick vegetable oils are heated and used in LHR engines the brake thermal efficiency improves. For every vegetable oil, there is an optimum temperature at which it gives the best performance.
Technical Paper

Experimental Evaluation of Mahua based Biodiesel as Supplementary Diesel Fuel

2009-04-20
2009-01-0479
Biodiesel developed from non- edible seeds grown in the wasteland in India can be very effectively utilized in the existing diesel engines used for various applications. This paper presents the results of investigations carried out in studying the fuel properties of mahua oil methyl ester (MOME) and its blend with diesel from 20% to 80% by volume. These properties were found to be comparable to diesel and confirming to both the American and Indian standards. The performance of mahua biodiesel (MOME) and its blend with diesel in a Kirloskar DAF8 engine has been observed. The addition of MOME to diesel fuel has significantly reduced CO, UBHC and smoke emissions but increases the NOx emission slightly. The reductions in exhaust emissions could help in controlling air pollution. The results show that no significant power reduction in the engine operation when operated with blends of MOME and diesel fuel.
Technical Paper

Effect of Fuel Injector Location and Nozzle-Hole Orientation on Mixture Formation in a GDI Engine: A CFD Analysis

2018-04-03
2018-01-0201
Gasoline direct injection (GDI) engines have gained popularity in the recent times because of lower fuel consumption and exhaust emissions compared to that of the conventional port fuel injection (PFI) engine. But, in these engines, the mixture formation plays an important role which affects combustion, performance and emission characteristics of the engine. The mixture formation, in turn, depends on many factors of which fuel injector location and orientation are most important parameters. Therefore, in this study, an attempt has been made to understand the effect of fuel injector location and nozzle-hole orientation on the mixture formation, performance and emission characteristics of a GDI engine. The mixture stratification inside the combustion chamber is characterized by a parameter called “stratification index” which is based on average equivalence ratio at different zones in the combustion chamber.
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