Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
13 results
Search Results
Item Combustion characteristics of diesel engine operating on jatropha oil methyl ester(Serbian Society of Heat Transfer Engineers, 2010) Dhananjaya, D.A.; Sudhir, C.V.; Mohanan, P.Fuel crisis because of dramatic increase in vehicular population and environmental concerns have renewed interest of scientific community to look for alternative fuels of bio-origin such as vegetable oils. Vegetable oils can be produced from forests, vegetable oil crops, and oil bearing biomass materials. Non-edible vegetable oils such as jatropha oil, linseed oil, mahua oil, rice bran oil, karanji oil, etc., are potentially effective diesel substitute. Vegetable oils have reasonable energy content. Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in diesel engines with very little or no engine modifications. This is because it has combustion characteristics similar to petroleum diesel. The current paper reports a study carried out to investigate the combustion, performance and emission characteristics of jatropha oil methyl ester and its blend B20 (80% petroleum diesel and 20% jatropha oil methyl ester) and diesel fuel on a single-cylinder, four-stroke, direct injections, water cooled diesel engine. This study gives the comparative measures of brake thermal efficiency, brake specific energy consumption, smoke opacity, HC, NOx, ignition delay, cylinder peak pressure, and peak heat release rates. The engine performance in terms of higher thermal efficiency and lower emissions of blend B20 fuel operation was observed and compared with jatropha oil methyl ester and petroleum diesel fuel for injection timing of 20° bTDC, 23° bTDC and 26° bTDC at injection opening pressure of 220 bar.Item Reduction of carbon emission by enhancing energy efficiency of forced draft fans in thermal power plants(Acta Press journals@actapress.com, 2014) Mandi, R.P.; Yaragatti, R.Y.In this paper, various techno-economical feasible methods for reducing the carbon emission by enhancing the energy efficiency of forced draft (FD) fans in coal-fired thermal power plants based on the energy audit study conducted in 28 numbers of 210MW power plants in India are discussed. The best operating points for pressure gain, flow, pressure drop, equipment efficiency, power input and specific energy consumption are simulated by using MATLAB, and presented in this paper with case study to validate the results. Optimizing the pressure at FD fan discharge and maintaining the optimum secondary air pressure at windbox will enhance the combustion characteristics. Operational optimization and control of excess air will reduce the auxiliary power of FD fans. Optimum sizing of FD fans and motors will reduce the auxiliary power by 0.10% gross energy generation and reduce the CO2 emission by 1,600 t/year.Item Effect of hydrogen addition on combustion and emissions performance of a high speed spark ignited engine at idle condition(Serbian Society of Heat Transfer Engineers, 2018) Shivaprasad, K.V.; Chitragar, P.R.; Kumar, G.N.The fuel depletion and environmental pollution have pushed studies on improving the combustion and emission characteristics of internal combustion engines with several alternative fuels. Expert studies proved that hydrogen is one of the prominent energy source which has exceptional combustion qualities that can be used for improving combustion and emissions performance of gasoline-fueled spark ignition engines. This paper introduced an experiment conducted on a single cylinder high speed gasoline engine equipped with a hydrogen injection system to discover the combustion and emissions characteristics with various hydrogen gasoline blends at idle condition. For this purpose, the conventional carburetted high speed spark ignition engine was modified into an electronically controllable engine with help of electronic control unit which dedicatedly used to control the ignition timings and injection duration of gasoline fuel. © 2018 Society of Thermal Engineers of Serbia.Item Effect of exhaust gas recirculation on a CRDI engine fueled with waste plastic oil blend(Elsevier Ltd, 2018) Ayodhya, A.S.; Lamani, V.T.; Bedar, P.; Kumar, G.N.The inevitable rise in the usage of plastic poses a serious threat to the environment owing to their non-biodegradable nature. The lack of proper infrastructure for treating and recycling plastic wastes give rise to the disposal problem. However, the oil synthesized from these waste plastics can be used as an alternative fuel for C.I engines which not only helps to tackle the disposal problem but also aids in recovering precious energy from these wastes. This experimental investigation aims to study the effects of plastic-diesel blend(P30) fuel on the performance, emission and combustion characteristics of a twin cylinder CRDI engine operating at different EGR rates (0%, 10% and 20%). The experimental results showed a slight drop in the engine performance while operating with plastic blend, mainly overall due to its higher viscosity and lower heating value. The vast upsurge of NOX emissions with plastic blend was mitigated by the aid of EGR methodology. Marginal increase in the discharge of regulated emissions like HC, CO and soot were noticed for both plastic blend as well as EGR operations. The experiments were carried out for five different loading conditions varying from 0% to 80% in steps of 20% each and found out that waste plastic-diesel blend can be successfully used as an alternative fuel in diesel vehicles without any prior modifications in the engine. © 2018 Elsevier LtdItem Cycle by cycle variations of LPG-gasoline dual fuel on a multi-cylinder MPFI gasoline engine(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2018) Vighnesha, N.; Shankar, K.S.; Dinesha, P.; Mohanan, P.Combustion stability of a multipoint port fuel injection spark ignition engine working on liquefied petroleum gas (LPG)-gasoline dual fuel mode of operation was analysed. LPG-gasoline ratio was varied from 0 to 100% by controlling the injector signals at wide open throttle condition and 3000 RPM. Increasing LPG ratio will give higher peak pressure and higher indicated mean effective pressure (IMEP) because of the higher flame propagation speed of LPG. The experiment showed that maximum pressure will occur nearer to top dead centre when compared to gasoline. Fluctuation in maximum pressure is higher for LPG and is minimum for 50% LPG. Time return map showed that combustion instabilibity will be more for 100% LPG and is less for 50% LPG. Coefficient of variation of IMEP and maximum pressure for gasoline is higher than LPG. With 100% LPG, NOx emission is almost three times that of gasoline. Hence it can be concluded that 50% LPG will give the better combustion characteristics when compared to other fuel blends. © 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group.Item Effect of bioethanol–diesel blends, exhaust gas recirculation rate and injection timing on performance, emission and combustion characteristics of a common rail diesel engine(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2019) Lamani, V.T.; Baliga M, A.U.; Yadav, A.K.; Kumar, G.N.This investigation is focused on the effect of exhaust gas recirculation (EGR) and injection timing on the performance, combustion and exhaust emission characteristics of common rail direct injection (CRDI) engine fueled with bioethanol-blended diesel using computational fluid dynamics (CFD) simulation. Simulation is carried out for various EGR rates (0, 10, 20 and 30%), two different injection timings, and two different bioethanol–diesel blends (10 and 20%) at injection pressure. The equivalence ratio is kept constant in all the cases of bioethanol–diesel blends. The results indicate that the mean CO formation and ignition delay increase, whereas mean NO formation and in-cylinder temperature decrease, with increase in the EGR rate. Further, with an increase in percentage of the bioethanol blends, CO and soot formation decrease as compared to neat diesel. A significant increase in in-cylinder pressure (15%) is found at 14° before top dead centre (BTDC) compared to 9° BTDC, which leads to an increase in indicated thermal efficiency of 4% for neat diesel at 30% EGR. In the present study, maximum indicated thermal efficiency is obtained in the case of 10 and 20% bioethanol–diesel blend, and remains constant for all EGR rates considered in the study. Obtained results are validated with the available literature data and indicate good agreement. © 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group.Item Effect of 1-pentanol addition and EGR on the combustion, performance and emission characteristic of a CRDI diesel engine(Elsevier Ltd, 2020) Radheshyam; Santhosh, K.; Kumar, G.N.Experimental study of 1-pentanol addition and EGR rates on the combustion, performance and emission of a CRDI diesel engine is carried out in this work. 1-Pentanol being a higher alcohol has fuel properties comparable to diesel. Experiments were conducted on a 4 stroke two cylinder, CRDI diesel engine running at a constant speed of 2000 rpm for lower load and higher load. Test fuels were prepared by blending the 1-pentanol with diesel, and tests were carried out for 5%, 10%, 20%, 30% and 40%, 1-pentanol blended in diesel on a volume basis. Effect of EGR rates of 10% and 20% were also studied. It had observed that engine can be run up to 30% of 1-pentanol blended fuel without any engine modification, but with raise in the percentage of 1-pentanol in the blends, BSFC increases and BTE decreases. Combustion characteristic for blended fuel depends upon the load. At higher load due to premixed combustion MGT, CP and NHR were almost same compared to the diesel. Reduction in NOx emissions was noted for all the fuel blends at the cost of HC and CO emission. 1-pentanol is a renewable biofuel, with use of 1-pentanol the dependency on petrodiesel can be overcome. © 2019 Elsevier LtdItem Effect of exhaust gas recirculation rate on performance, emission and combustion characteristics of a common-rail diesel engine fuelled with n-butanol–diesel blends(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2020) Lamani, V.T.; Yadav, A.; Gottekere, K.N.Increasing fears of fossil fuel attenuation and tough emission protocols compel the research community to explore alternative renewable fuels for diesel engines. Butanol is desirable among renewable fuels due to its properties favorable to diesel engines. This study focused on the suitability of exhaust gas recirculation (EGR) and optimum injection timing on the performance, combustion and exhaust emission characteristics of common-rail direct-injection (CRDI) engine fueled with n-butanol-blended diesel using experimental and computational fluid dynamics (CFD) simulation. Various EGR rates and injection timings are considered for different butanol–diesel blends (0, 10, 20 and 30%). Obtained simulation results are validated with experimental data and found to be in good agreement. For all EGR rates and blends, nitrogen oxide (NO) emission is reduced drastically, whereas carbon monoxide (CO) and soot emissions are decreased moderately, with increase in n-butanol–diesel blends. The CO and soot emissions increase with EGR rate due to oxygen deficiency as well. Brake thermal efficiency is reduced by approximately 1% for neat diesel (Bu0) with increase in EGR rates. Soot emission for Bu30 (15 ° Before top dead centre (BTDC) is decreased by 23, 25, 24 and 26% for 0, 10, 20 and 30% EGR rates, respectively, compared to Bu0 (12° BTDC). © 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group.Item Experimental studies on the impact of part-cooled high-pressure loop EGR on the combustion and emission characteristics of liquefied petroleum gas(Springer Science and Business Media B.V., 2020) Oommen, L.P.; Kumar, G.N.Liquefied petroleum gas is preferred and adopted in automotive engines because of its efficient burning and cleaner emission characteristics. Since LPG contains less carbon molecules and higher carbon to hydrogen ratios than gasoline or diesel, it has a much higher emission reduction potential both in the cases of regulated and non-regulated emissions. A major disadvantage of deploying LPG widely is the amount of NOx generation owing to the higher temperatures developed in the combustion chamber. In this study, part-cooled EGR is applied in varying rates (12%, 18%, 24%) in order to analyze the effects produced in the performance and emission characteristics of a multicylinder MPFI engine fuelled by 100% LPG at four different loading conditions and four different operating speeds. It can be observed that the application of an optimum rate of cooled EGR reduces the NOx emissions drastically even though at the expense of hydrocarbon emissions. The fuel consumption of the test engine is reduced up to 12.28% with the application of 18% percentage of part-cooled EGR. It can be inferred from the experimental studies that 18% part-cooled EGR is the optimum flow rate of recirculation which is most effective during the part load operation of the engine (50–75%) and at higher engine speeds. However, the emission of oxides of nitrogen reduced by 7.8% at 24% recirculation. The statistical analysis of combustion shows a reduction in combustion stability with increased flow of recirculation. © 2020, Akadémiai Kiadó, Budapest, Hungary.Item Combustion, performance, and emission characteristics of dairy-washed milk scum biodiesel in a dual cylinder compression ignition engine(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2020) Srikanth, H.V.; Venkatesh, J.; Godiganur, S.; Manne, B.; Bharath Kumar, S.; Spurthy, S.The present work has been carried out to study the suitability of milk dairy waste scum (MDWS) biodiesel as a fuel for diesel engine. The investigations were carried out on performance, emission and combustion characteristics of a direct injection dual cylinder diesel engine fueled with MDWS methyl ester, and their blends. Two-step transesterification process was used to synthesize the MDWS biodiesel, characterization according to specified ASTM D6751-15C standards. The performance characteristics studies showed an increased brake thermal efficiency of B20 (3%) and B30 (0.94%) blends in comparison to fossil diesel. However, the increased brake specific fuel consumption (BSFC) was also found with all the fuel blends and an higher (9%) BSFC was obtained with B50 compared to diesel fuel at full load condition. The emissions of blends were found to be lower in comparison with diesel fuel, except for nitrogen oxides. A 32% increase in NOx emission was found with B50 blend compared to diesel fuel at maximum load condition. However, improved combustion characteristics would found with MDWS blends with respect to in-cylinder pressure, ignition delay, and heat release rate compared to fossil diesel. © 2019 Taylor & Francis Group, LLC.