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This study was carried out to evaluate the variation in performance and emission characteristics of a multi cylinder Multi-point Fuel Injection (MPFI) automotive Spark Ignition (SI) engine after incorporating an additional manifold for gas injectors to throttle body. To install gas injectors for Compressed Natural Gas (CNG)/Hydrogen-CNG (HCNG) operation throttle body of the engine was modified using a novel manifold. The performance and emission characteristics of the existing throttle body and the new throttle body configuration were evaluated. The parameters studied were Manifold Air Pressure (MAP), Torque and Emissions (HC, CO, CO2, and NOx) for gasoline operation. The influence of installing new manifold on these parameters was evaluated. It was important to evaluate the degree of variation of the parameters on the gasoline operation so that the addition of new manifold for gas operation could be validated. The measurement was carried out at wide open throttle.

The fuel crises of the 1970's and early 1980's focused attention on the desirability of developing alternative fuels and decreasing the dependency on petroleum-based fuels. Vegetable oils and derivatives are among the materials that were extensively investigated as alternative diesel fuels. Vegetable oils are a potential alternative to the partial or total substitution of diesel fuels. It was known that short-term engine tests have been successful with vegetable oils; however, long-term tests have revealed the fuel limitations regarding lubricating oil contamination, deposits on engine surfaces and performance problems. This study shows how the added advantages of air-cooled engine over the water-cooled engine become the preferred choice for the SVO run diesel engine. Based on the 100 hrs SVO run diesel engine, the modification has been carried out for the long run. Different emission measurements were carried out and studied in comparison with conventional diesel.

The performance and emission of spark ignition engines are optimized using combustion characteristics. The flame characteristics such as flame kernel growth rate, flame speed, flame development angle, rapid burning angle, over all burning angle and drift velocity influence the combustion process of SI engines. In this direction, experiments were conducted to measure flame kernel growth rate in AVL research spark ignition engine using AVL VISIO FEM instrument. The flame kernel growth rate measured at different engine speeds and spark timing. The measured flame kernel growth rate for gasoline fuel was in the range of 4 to 6 m/s. It was observed from the results that flame kernel growth rate is the highest at MBT spark timing. The effects of flame kernel growth rate on performance and emission characteristics were analyzed in detail. Brake thermal efficiency increases with the increase of flame growth rate. CO emission is good agreement with the kernel growth rate.

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.

Ethanol is an alternative renewable fuel produced from various agricultural products. Ethanol-diesel emulsion technique is used for the utilization of ethanol in diesel engines wherein ethanol is used without any modification. The performance, combustion and emission characteristics of a direct injection (DI) diesel engine for off-highway application were evaluated using ethanol-diesel microemulsions. The addition of ethanol to diesel fuel simultaneously decreases calorific value, kinematic viscosity and stability of fuel. Ethyl acetate was used as an additive/ingredient to keep the blends in homogeneous and stable state. Blends (D80/E13/EA07; D70/E17/EA13; D60/E23/EA17) were selected for engine experiments based on stability behavior and fuel properties. The results showed no significant power reduction in the engine operation with ethanol-diesel microemulsions.

The methyl ester of karanja oil, known as biodiesel, is receiving increasing attention as an alternative fuel for diesel engine. This paper presents the results of investigations carried out in studying the fuel properties of karanja oil methyl ester (KOME) and its blend with diesel from 20% to 80% by volume and in running a DI diesel engine with these fuels. Engine tests have been carried out with the aim of obtaining performance characteristics such as Brake specific fuel consumption(BSFC), brake thermal efficiency, brake power, exhaust gas temperature, emission such as CO, UBHC, NOx, smoke opacity and combustion parameters to evaluate and compute the behavior of the diesel engine running on KOME and its blends with diesel fuel. The addition of KOME to diesel fuel has significantly reduced CO, UBHC and smoke emissions but it increases the NOx emission slightly.

Compressed Natural Gas (CNG) has already been adopted as a regular transportation fuel in many countries including parts of India. On the other hand hydrogen, despite its proven “clean-burning” characteristics is not being widely used as an alternative fuel. This paper explains how addition of hydrogen to existing CNG-fuelled engine can ensure an early entry of hydrogen into our energy infrastructure. In the context of the present discussion such a system is being referred to as Hydrogen Added Natural Gas (HANG) fuelled engine. Tests in IIT Delhi have shown an improvement in the performance characteristics of HANG operation of an engine over neat CNG operation. Reduction in the level of emission was also observed with HANG engine.

Performance, combustion and emission characteristics relating to the use of 20% methanol and 80% gasoline in a spark ignition engine are described in this paper. The engine used for experimental purpose is a motorcycle engine of 13.4 kW (18 hp). A new online multi liquid fuel mixing system has been developed for perfect mixing and hence found to be better for investigating effects of Methanol - Gasoline blend (M20) which enhances engine performance and reduces exhaust emissions. Performance tests conducted under Throttle Body Injection (TBI) showed considerable performance improvement in power output and in thermal efficiency, as well as substantial reduction in BSFC, HC, and CO emissions than that of a conventional carbureted engine. The results of this work can contribute to improve the air pollution in the urban area.

Performance, combustion and emissions investigations relating to the use of gasoline injection in a spark ignition engine are described in this paper. The engine used for experimental purpose is a motorcycle engine of 13.4 kW (18 HP). Experimental engine test setup is designed to operate in carburetion as well as in injection mode [1]. Electronic controlled throttle body injection system is designed to operate test engine in injection mode. This paper also present the procedure used for gasoline fuel injection optimization and discussed the results obtain for minimum fuel consumption, for maximum power and for minimum brake specific fuel consumption, for optimization of the start of injection (i.e. injection delay), injection duration and injection pressure, for the entire operating range, of the research engine used for investigation.

Fuel induction techniques have been found to be playing a very sensitive role in the operation of a gas-fueled engine. This paper describes the experimental evaluation of an electronic injector for operating a spark ignition (SI) engine using clean-burning alternative fuels such as compressed natural gas and hydrogen. Test data have also been generated with a blend of the two fuels (hydrogen and CNG) in various proportions to determine the flow characteristics of the blend for engine operation. Results show that the electronic injectors for gaseous fuel operation can be conveniently adapted to existing engines. A precise and accurate control of flow was achieved at pressure levels of 3.44 bar and 9.31 bar (absolute pressure).