Faculty Publications
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Item Effect of Diethyl Ether on the Performance and Emission of a 4 - S Di Diesel Engine(SAE International, 2004) Mohanan, P.; Kapilan, N.; Reddy, R.P.Dimethyl Ether (DME), the methanol analog to Diethyl Ether (DEE), was recently reported as a low emission, high quality diesel fuel replacement. Literature review indicates that significant work is not carried out with respect to its performance analysis and in regard to pollution levels. In the present work, the effect of DEE on the performance and emissions of a four-stroke direct injection diesel engine have been studied. Tests were conducted on the diesel engine with different blends of DEE and diesel as fuel. Test results show that 5 % DEE blend gives better performance and low emissions compared to other blends of DEE and diesel fuel. Hence, 5 % DEE can be blended with diesel fuel to improve the performance and to reduce emissions of the diesel engine. © 2003 SAE International.Item Performance and emission studies on the effect of injection timing and diesel replacement on a 4-S LPG-Diesel Dual-Fuel Engine(SAE International, 2003) Sudhir, C.V.; Desai, V.; Kumar, S.Y.; Mohanan, P.Reducing the emissions and fuel consumption are no longer future goals; instead they are the demands of the day. People are concerned about rising fuel costs and effects of emissions on the environment. Diesel engines are the major contributors to the increased levels of pollutants. In the present work an attempt is made for effective utilization of diesel engine with reduced fuel consumption, smoke density and NOx emissions. This is achieved by some minor modifications in diesel engine so as to run it as LPG-Diesel Dual-fuel engine with LPG (Liquefied Petroleum Gas) (70% Butane + 30% Propane) induction at air intake. The important aspect of LPG-Diesel dual-fuel engine is that, it shows significant reduction in smoke density, NOx emission and improved brake thermal efficiency with reduced energy consumption. An existing 4-S, single cylinder, naturally aspirated, water-cooled, direct injection, C.I. engine test rig was used for the experimental purpose. With proper instrumentation the tests were conducted under various LPG flow rates, loads, and injection timings. The influence of the diesel replacement by LPG on smoke density, brake specific energy consumption and brake thermal efficiency was studied. The optimal diesel replacement pertaining to the maximum allowable LPG flow limits could be assessed with these experiments. The influence of the injection timing variation on the engine performance and smoke density was analyzed form the experimental results. It was observed that beyond half load operation of the dual-fuel engine, thermal efficiency increased with diesel replacement, and at full load up to 4% improvement was observed compared to full diesel operation. There was drastic reduction in NOx emissions (up to40- 60 %) for the entire load range, except near full load where NOx increased (by38%) beyond full diesel value at normal injection timing. At full load reduction in smoke density up to 40% to 60% was observed compared to full diesel operation. At advance injection timing of 30°btdc the performance of the dual fuel engine was better with lower smoke density, while the NOx emission was found to be higher. Copyright © 2003 SAE International.Item Studies on esters of coconut oil as fuel for LPG-Biodiesel dual fuel engine(American Society of Mechanical Engineers Three Park Avenue New York NY 10016-5990, 2003) Kapilan, N.; Reddy, R.P.; Mohanan, P.The rapid depletion in world petroleum reserves and uncertainty in petroleum supply due to political and economical reasons, as well as, the sharp escalation in the petroleum prices, have stimulated the search for alternatives to petroleum based fuels specially diesel and gasoline. Biodiesel is one of the renewable fuels, which will be the good replacement to diesel. But as a sole fuel, it gives poor performance and higher emissions. From the literature survey, it is observed that not much work has been done to use Methyl Ester (ME) of coconut oil as liquid fuel in sole and dual fuel mode of operation. Hence, in the present work, ME of coconut oil is chosen as a sole fuel to run the diesel engine and an alternative pilot fuel to run LPG-Biodiesel dual fuel engine. In dual fuel mode operation, LPG is used as the inducted gaseous fuel. LPG has been chosen as the inducted fuel on account of its easy availability in abundance in the present time. The existing compression ignition diesel engine was modified to work on dual fuel mode. Tests were carried out on a single cylinder, four strokes, water-cooled, direct injection, compression ignition engine using ME of coconut oil as fuel. To study the effect of injection timing, its is advanced and retarded from the standard injection timing recommended for diesel operation. From the results, it is observed that the advanced injection timing results in better performance and lower emissions of the diesel engine. In dual fuel mode operation, first the engine was started with ME of coconut oil as fuel and then the LPG flow rate was increased. With appropriate proportions of the injected (0.45, 0.65 and 0.75 kg/hr) and inducted fuels it is possible to improve the engine performance and reduce its emissions. From the experimental results, it is found that the pilot fuel rate of 0.65 kg/hr is preferred from the point view of brake thermal efficiency, fuel consumption and smooth running. ME of coconut oil were successfully used as sole fuel and pilot fuel. The performance and emission of the engine in sole fuel mode with better injection timing and dual fuel mode with better pilot quantity were compared. From the comparison, it is observed that the ME of coconut oil can be used as pilot fuel in dual fuel engine compared to sole fuel with regard to performance and emissions.Item Studies on influence of injection timing and diesel replacement on LPG-diesel dual-fuel engine(2003) Sudhir, C.V.; Desai, V.; Suresh Kumar, Y.; Mohanan, P.Reducing the emissions and fuel consumption for IC engines are no longer the future goals; instead they are the demands of today. People are concerned about rising fuel costs and effects of emissions on the environment. The major contributor for the increased levels of pollutants is the Diesel engines. Diesel engine finds application in almost in all fields, including transportation sector such as buses, trucks, railway engines, etc. and in industries as power generating units. In the present work an attempt is made for effective utilization of diesel engine aiming for reduction in fuel consumption and smoke density. This is achieved by some minor modifications in diesel engine, so as to run the existing diesel engine as a LPG-Diesel dual-fuel engine with LPG (Liquefied Petroleum Gas) induction at air intake. The important aspect of LPG-Diesel dual-fuel engine is that it shows significant reduction in smoke density and improved brake thermal efficiency with reduced energy consumption. An existing 4-S, single cylinder, naturally aspirated, water-cooled, direct injection, CI engine test rig was used for the experimental purpose. With proper instrumentation the tests were conducted under various LPG flow rates, loads, and injection timings. The influence of the diesel replacement by LPG on smoke density, brake specific energy consumption and brake thermal efficiency were studied. The optimal diesel replacement pertaining to the maximum allowable LPG gas flow limits could be assessed with these experiments. The influence of the injection timing variation on the engine performance and smoke density were analyzed form the experimental results. It was also observed that beyond half load operation of the dual-fuel engine, the brake thermal efficiency increases with diesel replacement, and at full load up to 4% improvement was observed compared to full diesel operation. At full load reduction in smoke density up to 25-36% was observed compared to full diesel operation. At advance injection timing of 30°btdc the performance was better with lower emissions compared to normal and retarded injection timings. Copyright © 2003 by ASME.Item Studies on influence of injection timing and Diesel replacement on LPG-Diesel dual-fuel engine(2003) Sudhir, C.V.; Desai, V.; Suresh Kumar, Y.; Mohanan, P.Reducing the emissions and fuel consumption for IC engines are no longer the future goals; instead they are the demands of today. People are concerned about rising fuel costs and effects of emissions on the environment. The major contributor for the increased levels of pollutants is the Diesel engines. Diesel engine finds application in almost in all fields, including transportation sector such as buses, trucks, railway engines, etc. and in industries as power generating units. In the present work an attempt is made for effective utilization of diesel engine aiming for reduction in fuel consumption and smoke density. This is achieved by some minor modifications in diesel engine, so as to run the existing diesel engine as a LPG-Diesel dual-fuel engine with LPG (Liquefied Petroleum Gas) induction at air intake. The important aspect of LPG-Diesel dual-fuel engine is that it shows significant reduction in smoke density and improved brake thermal efficiency with reduced energy consumption. An existing 4-S, single cylinder, naturally aspirated, water-cooled, direct injection, CI engine test rig was used for the experimental purpose. With proper instrumentation the tests were conducted under various LPG flow rates, loads, and injection timings. The influence of the diesel replacement by LPG on smoke density, brake specific energy consumption and brake thermal efficiency were studied. The optimal diesel replacement pertaining to the maximum allowable LPG gas flow limits could be assessed with these experiments. The influence of the injection timing variation on the engine performance and smoke density were analyzed form the experimental results. It was also observed that beyond half load operation of the dual-fuel engine, the brake thermal efficiency increases with diesel replacement, and at full load up to 4% improvement was observed compared to full diesel operation. At full load reduction in smoke density up to 25-36% was observed compared to full diesel operation. At advance injection timing of 30°btdc the performance was better with lower emissions compared to normal and retarded injection timings.Item Experimental investigations on a compressed natural gas operated dual fuel engine(2005) Kapilan, N.; Somayaji, C.; Mohanan, P.; Reddy, R.P.In the present work, an attempt has been made for the effective utilization of Compressed Natural Gas (CNG) in diesel engine. A four stroke, single cylinder diesel engine was modified to work on dual fuel mode. The effect of CNG flow rate and Exhaust Gas Recirclulation (EGR) on the performance and emissions of the dual fuel engine was studied. The variables considered for the tests were different CNG flow rates (0.2, 0.3, 0.4, 0.5, 0.6 and 0.7 kg/hr), EGR (0%, 4.28%, 6.63 % and 8.12%) and loads (25%, 50%, 75% and 100 % of full load). From the test results, it was observed that the EGR rate of 4.28 % results in better brake thermal efficiency and lower CO and NOx emissions than other ERG rates at 25%, 50% and 75% of full loads. At full load, EGR rate of 8.12 % results in higher brake thermal efficiency and lower NOx emissions. Copyright © 2005by ASME.Item EFFECT of INJECTION PRESSURE and INJECTION TIMING on A SEMI-ADIABATIC CI ENGINE FUELED with BLENDS of JATROPHA OIL METHYL ESTERS(SAE International, 2008) Dhananjaya, D.A.; Mohanan, P.; Sudhir, C.V.A naturally aspirated four stroke single cylinder CI engine was modified to run as semi-adiabatic CI engine. The effect of different injection pressure and injection timing of a standard and semi-adiabatic engine on the combustion performance and emission characteristics of jatropha oil methyl ester (JOME) and its volume blends with diesel is presented in this paper. Performance of the CI engine was evaluated in terms of brake specific energy consumption, brake thermal efficiency, exhaust gas temperature and exhaust gas composition. Five different volume blends of JOME viz. B5, B10, B15, B20 and B25 was used for the combustion studies at various injection pressures viz. 180, 200, 220 and 240 bar and also at different injection timings i.e. 22°,27° and 32° btdc. This experimental study focused on deriving an optimal injection timing and pressure for the satisfactory operation of JOME blends in a semi-adiabatic engine. The study revealed that acceptable brake thermal efficiency, brake specific energy consumption and emission characteristics of the engine were obtained up to B25 of JOME. At injector opening pressure of 220bar, B20 blend fuel showed better combustion performance and lower exhaust emissions compared to other blends and diesel fuel. At this combination the specific energy consumption were 11.67 MJ/kW-hr and brake thermal efficiency were 30.87% for a semi-adiabatic engine, while the same for standard engine (Non Coated), was found to be 12.60 MJ/kW-hr and 28.67% respectively. At full load, with injection timing of 32° btdc and with B20 JOME blend fuel showed the specific energy consumption of 11.52 MJ/kW-hr and thermal efficiency of 31.72% for semi-adiabatic engine, while for standard engine same was found to be 12.21 MJ/kW-hr and 29.28% respectively. This infers that the semi-adiabatic engine showed better combustion than the standard engine. © 2008 SAE International.Item Performance and emission studies of diesel engine using diethyl ether as oxygenated fuel additive(SAE International, 2008) Kapilan, N.; Mohanan, P.; Reddy, R.P.There is currently interest in finding means to improve motor vehicle fuel economy while complying with emissions regulations. Fuel additives have been widely reported to improve engine cleanliness and performance with diesel engines. Diethyl Ether (DEE) has high octane number and compatible with current vehicle technology and fuel infrastructure. Although DEE has long been known as a cold start aid for engines, knowledge about using DEE for other operations, such as significant component of a blend or additive is limited. In this present work, experiments were conducted to study the influence of DEE on the performance and emissions of a 4-S direct injection diesel engine. From the experimental results, it is observed that the addition of DEE to diesel fuel improves the performance of the diesel engine. A slight improvement in the thermal efficiency and reduction in smoke, carbon moNOxide and hydro carbon emissions were observed with B5 Blend (5 % DEE + 95 % Diesel). © 2008 SAE International.Item Optimizing brake specific fuel consumption of low-NOx, emission standard compliant CI engines, by tuning engine parameters(Combustion Institute, 2009) Menon, P.G.; Mohanan, P.Reducing NOx from about 10.7 g/bhp-hr to about 4.5 g/bhp-hr caused a 6% loss in fuel economy in engine designs of the late 1980s and early 1990s [1]. Reasons for this loss in fuel economy are attributed to the loss in peak combustion pressure due to the delayed fuel injection among other technologies used in NOx control that leads to reduced cycle work. To compensate for the loss of work output, more fuel is provided to produce the desired work and leading to increased Brake Specific Fuel Consumption (BSFC). To optimize BSFC in Automobile Diesel Engines using Low-NOx technologies like fuel injection retard and fuel injection rate shaping, to stay within emission norms, a transient model was developed in Matlab/Simulink to control and optimize the various engine parameters contributing to the production of NOx and to realistically determine an ideal operating point for the functioning of an engine of a given configuration keeping in mind NOx production as well as BSFC. © 2009 Combustion Institute. All rights reserved.Item Effect of bio-diesel (B20) on performance and emissions of optimum injector opening pressure operating at different injection timings of a semi-adiabatic engine(Combustion Institute, 2009) Dhananjaya, D.A.; Sudhir, C.V.; Mohanan, P.This study was carried out to investigate the performance and emission characteristics of jatropha methyl ester oil and its blend B20 with mineral diesel on a single-cylinder four-stroke direct injection water cooled diesel engine operated at optimum IOP 220bar at different injection timing of standard and semi-adiabatic engine. The results of comparative measures of brake thermal efficiency, smoke and NOx have been presented and discussed on both the types of engines. The engine performance in terms of higher thermal efficiency and lower emissions of B20 blend fuel operation was observed and compared with jatropha methyl ester oil and mineral diesel fuel of 20o bTDC, 23o bTDC and 26o bTDC of standard and semi-adiabatic engine. © 2009 Combustion Institute. All rights reserved.