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Author: search.filters.author.Oommen, L.P.Subject: search.filters.subject.Gasoline

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    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.
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    Assimilative capacity approach for air pollution control in automotive engines through magnetic field-assisted combustion of hydrocarbons
    (Springer Science and Business Media Deutschland GmbH, 2021) Oommen, L.P.; Gottekere Narayanappa, K.G.
    Deterioration of air quality through the combustion of hydrocarbon fuels has been one of the global transboundary problems put before the research community since last five decades. According to the updated statistics, 79% of energy needs in India are met by fossil fuel combustion which results in the emission of toxic pollutants like carbon monoxide, oxides of nitrogen, and unburned hydrocarbons. Air quality has seriously been affected in many parts of India, and statistically, 13 out of 15 most polluted cities in the world lie in India. Magnetic field-assisted combustion has been proven as a reliable technology in internal combustion engines for enhancing the combustion of fuels and reduction of harmful emissions that are the byproducts of incomplete combustion of fuels. In the present work, the magnetic field-assisted combustion of a liquid-phase and a gas-phase fuel (gasoline and LPG) has been studied in a multicylinder automobile engine replicating on road driving conditions in a laboratory focusing on the levels of emissions in comparison with normal combustion of both the fuels. The experimental study concludes that the applied magnetic field positively influences combustion, resulting in reduced level of emission of toxic components irrespective of the phase of hydrocarbon fuels. It is also observed that the percentage reduction in emissions increases with increase in intensity of magnetization. The maximum reduction obtained for CO and UBHC emissions through this technique is 20.58% and 14.47%, respectively. The effectiveness of MFAC in countering air pollution from vehicular exhaust is also studied with respect to fuel phase and mode of operation. The effectiveness of MFAC is observed to be more in high-speed operation of the engine and decreases in the order CO > UBHC > NO. The obtained emission results have a cumulative significance as 45% of total air pollution in India is caused by combustion of hydrocarbons in automotive engines. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.
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    Experimental studies on the influence of axial and radial fields of sintered neo-delta magnets in reforming the energy utilization combustion and emission properties of a hydrocarbon fuel
    (Taylor and Francis Ltd., 2024) Oommen, L.P.; Kumar, G.N.
    Permanent magnets based on rare earth components have been increasingly finding their applications in modern technologies. Although the magnetic properties tend to deteriorate rapidly at temperatures in excess of 150ºC, sintered NdFeB magnets can be employed in reforming the physical and combustion properties of hydrocarbon fuels. In the present investigation, two different magnetization patterns of high-grade NdFeB magnets are applied in varying intensities on a multicylinder MPFI engine fueled by gasoline and the alteration in combustion and emission properties of the fuel are studied. The magnetic field restructures the hydrocarbon molecules and causes the pseudo clusters to break away thus reducing the inherent viscosity and enhancing the association of hydrocarbon molecules with the oxidizer. The effectiveness of two different magnetization patterns of sintered NdFeB magnetic material in reforming the combustion characteristics is studied and compared. The study shows a maximum increase of 9.2% in power output and 7.74% in thermal efficiency of the test engine along with a significant reduction in the generation of toxic emissions that are the byproducts of combustion. The study also concludes that radial magnetic fields are more effective in conditioning the fuel and reducing the emission of CO, HC, and NOx by 8.57%, 5.52%, and 1.25% compared to the same intensity fields under axial magnetization. The combustion behavior of gasoline is studied under both field patterns. The statistical analysis of mean effective pressures through radar plots is conclusive of the reduction in cycle by cycle variations under magnetic field-assisted combustion. Abbreviations: NdFeB:Neodymium Iron Boron permanent magnet; SmCo:Samarium Cobalt permanent magnet; MPFI:Multipoint Port Fuel injection; BP:Brake Power; BTE:Brake Thermal Efficiency; BSFC:Brake Specific Fuel Consumption; NHRR:Net Heat Release Rate; IMEP:Indicated Mean Effective Pressure; COV:Coefficient of Variation; CO:Carbon Monoxide; CO2:Carbon dioxide; HC: hydrocarbon; NOxOxides of Nitrogen. © 2020 Taylor & Francis Group, LLC.