Advanced Materials Research Vol. 768

Abstract: The motive of the experimentation is to improve the combustion of the direct injection diesel engine powered with biodiesel blend. Initial experimentation was made with the diesel in a conventional unmodified diesel engine. By careful literature survey and technical reviews 20% blend of Pongamia biodiesel with 80% of diesel (B20) had been taken as a test fuel. The swirl motion inside combustion chamber is increased by means of providing the swirling grooves over the piston crown with constant depth 2 mm and variable width of 5.5mm, 6.5 mm and 7.5 mm, unless the previous work done by researches the care has been taken to maintain the compression ratio of the engine. Among the various configurations, the swirling grooves of depth 2mm and width 6.5 mm showed the increase in brake thermal efficiency up to 11 % and decreasing trends in hydrocarbon, carbon monoxide, and smoke emissions. Thus the findings of the present work showed the increase in performance and reduction in the emission of the direct injection diesel engine fuelled with Pongamia biodiesel blend.

Abstract: The objective of this study is to investigate the feasibility of two-stage injection on combustion and exhaust emission characteristics in diesel (main fuel) ethanol (pilot fuel) fuelled single cylinder diesel engine. The pressure crank angle and net heat release rate diagrams revealed that increase in the ethanol pilot quantity causes an increase in the ignition delay in the pilot combustion and hence the main combustion due to diesel fuel is slightly influenced by the ethanol pilot fuel. The increase in the pilot injection decreases the NOx considerably. The concentration of soot emissions also decreases with increase in pilot injection. The CO emissions increases with increase in pilot injection and a slight increase in HC emission is observed.

Abstract: The evolution of four stroke engines and improved environmental pollution control norms has pushed the two-stroke engines towards obsolescence due to their inherent design problems. This has made the existing manufacturers & users of two-stroke engines a setback. In this paper attempt has been made to high light the performance parameters in respect of fuel efficiency and emission control. In this research work an effort is made to retrofit the commonly used two stroke engine for optimal performance by using EFI engine. It mainly includes injector locations with reference to spark plug which decides the combustion efficiency of engine. It also includes the location of different sensors and subsequent modification of silencer. As the automobile engine has to operate at higher speeds, proper and firm mounting of different electronic part is essential which affects the performance of engine. After mechanical modification of engine with EFI system it is tested by connecting it to dynamometer. The results are compared with that of carbureted engine.

Abstract: Random extraction and consumption of fossil fuels have leads to a reduction in petroleum reserves. As for as developing countries like India is connected the need to search for alternative fuels is most urgent as India is heavily dependent upon the import of petroleum to meet its demands for automotive and power sectors. This has inspired curiously in alternative sources for petroleum based fuels. An alternative fuel must be economically competitive and environmentally acceptable. India has great potential for production of biofuels like Biodiesel from vegetable seeds. In the quest to find an alternative to the existing diesel and petrol fuels various Biodiesel and alcohol has been tried and tested in the Internal Compression engine. In this direction, an attempt has been made to investigate the performance and emission characteristic of Biodiesels and compare it with diesel. The Biodiesels considered are Tamanu, Mahua and Pongamia were tested with four stroke diesel engine. A drastic improvement in reduction of Hydrocarbon (HC) and Carbon monoxide (CO) were found for Biodiesels at high engine loads. Smoke and Nitrogen oxides (NOx) were slightly higher for Biodiesels. Biodiesels exposed similar combustion stages to diesel fuel. Therefore use of transesterified vegetable oils can be partially substituted for the diesel fuel at most operating conditions in term of the performance parameters and emissions without any engine modification.

Abstract: Diesel engine combustion modeling presents a challenging task as the injection starts with the spray formation and breakup of spray into droplets. The computation involved in predicting the in-cylinder fluid mixture during combustion using eulerian and lagrangian approach is rather a cumbersome task. In this work, 3D-CFD computations are performed to understand the behaviour of spray droplet variables on combustion process and emissions in a direct injection diesel engine. The study involves the computation of turbulent flow-field quantities, modelling various processes such as fuel spray distribution, atomization, collision, evaporation, combustion and pollutant formation using a commercial CFD code. Grid independence and time independent studies are carried out for finding the optimum grid size and time step. The numerical results predicted using CFD code is validated with the experimental data available from the literature. The process of combustion and emission characteristics is investigated numerically with respect to spray characteristics. The work is further extended to study the effect of swirl ratio and injection timing on droplet parameters.

Abstract: Multilevel inverters have been gaining immense popularity in high power applications such as Electric vehicles, Flexible AC Transmission Systems etc. This paper focuses on an asymmetric cascaded multilevel inverter employing the variable frequency carrier phase shifted PWM technique. The major advantage of this strategy is that it aids in balancing the switch utilization. The proposed strategy was found to have lower THD and switching losses when compared to the conventional strategies. The simulation was performed using MATLAB/Simulink and the results were verified experimentally.

Abstract: The purpose of this study is to investigate the impact of bio fuel enhancer additive added to 20% cashew nut shell liquid (CNSL) biodiesel blended with No.2 diesel fuel, in terms of the performance and exhaust emissions on a 4-cylinder naturally-aspirated direct-injection diesel engine. Experiments were conducted under five engine loads at a steady speed of 1500 rpm. The influence of blends on carbon monoxide (CO), nitrogen oxide (NO), carbon dioxide (CO₂), hydrocarbon emission and smoke opacity were investigated. . The experimental results showed that the bio fuel enhancer additive improves the performance parameters and decreases CO emission by 13% and HC emission by 15% as compared to biodiesel. Bio Fuel Enhancer (BFE) additive reduces the NO emission remarkably by 55% as compared to biodiesel.

Abstract: In this study, the performance and exhaust emissions of a biodiesel fuelled low heat rejection (LHR) direct injection Diesel engine have been investigated experimentally and compared with the results of standard diesel engine without any coatings. Piston, cylinder head, exhaust and inlet valve of test engine were coated with 0.5 mm thickness of zirconia through plasma spray method. Biodiesel used in the testing was prepared from rice bran oil through transesterification process.

Abstract: Biomass derived vegetable oil is a promising alternative fuel for an internal combustion engine. Direct use of vegetable oil has inferior performance with higher emission due to its higher viscous in nature. This can be overcome by transesterification process with its byproduct which is called as used vegetable oil methyl ester. While blending this biodiesel with fossil diesel upto maximum of 30:70, will give the higher performance and lower emission than the fossil diesel alone. In this present study biodiesel in the form of B23 is used in a four stroke water cooled variable compression ratio engine without any modifications. The performance and emission characteristics are studied with different compression ratio and compared with a base line fossil diesel mode operation. This study reveals that the compression ratio of 18 is the optimum in the view of ignition delay, maximum pressure crank angle, exhaust gas temperature and Smoke emission.

Abstract: In present scenario Bio-fuel act as the major role in todays fuel compensation. In India Neem tree is a broadly grown up termed as a divine tree due to its large revalance in many areas of study. The current research study is projected to consider aspect related to the possibility of preparation of Biodiesel from Neem oil. This research deals with Biodiesel preparation from neem oil, which is mono ester prepared using transesterification process. Biodiesel is a safe substitute fuel to replace established petroleum diesel. It has maximum lubricity is a clean burning fuel and can be a fuel component for use in existing unmodified diesel engine. Neem (Azadirachita Indica) is a tree. Various habitual uses of pure neem oil in agriculture, medicine, etc. Neem oil has natural fungicidal, pesticidal, and medicinal properties. Neem a natures gift it categorized in to non edible oil and mainly used in medicine and cosmetic product. Biodiesel has been gaining increased concentration from Internal Combustion Engine researcher in observation of the energy crisis and increasing environmental problems. Neem oil is being considered for biodiesel and more research is being done in this area and also lot of research going on. Biodiesel designed for complete compatibility with petroleum diesel and can be blended in any ratio from additive levels to 100% Biodiesel. The fuel properties of biodiesel including kinematic viscosity and acid value were checked. The engine power and pollutant emissions characteristics under different biodiesel percentages were also studied. Experiments demonstrated in the single cylinder diesel engine that the biodiesel produced using neem oil could reduce smoke and Carbon monoxide emissions, extensively while the NOx emission changed a little. Thus, the ester of this oil can be used as eco-friendly substitute fuel for (C I) diesel engine.