Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
5 results
Search Results
Item Use of vegetable oil ester in CI engine: Some studies under overload condition(Combustion Institute, 2007) Bekal, S.; Ashok Babu, T.P.A.A CI engine under certain operating condition is subjected to overloading. An experimental investigation has been carried out to compare the NOX and particulate emission of a CI engine when fueled with diesel and vegetable oil ester separately, for overload condition. The resulting increase(or decrease) in parameters like BSEC, exhaust temperature and CO,NOX,CO2 & O2 emission are compared for ester at full load and overload conditions. Proportion of overload considered is 10% more than the full load. The combustion characteristics like peak pressure, crank angle at peak pressure etc., have been obtained from data acquisition system. The vegetable oil chosen for study is sunflower oil ester. To find the appropriate injection timing under overload condition, the engine has been run at three different injection timings Viz., 24.5 bTDC(normal), 23 bTDC and 21.5 bTDC. The results indicated that slight retardation in injection timing is beneficial for vegetable oil ester under overload condition. © 2007 Combustion Institute. All Rights Reserved.Item Some studies on chemical composition, and properties of ester of edible and inedible vegetable oils, and their use in CI engine(Combustion Institute, 2009) Bekal, S.; Ashok Babu, T.P.A.In this work, the esters produced from two types of vegetable oils – edible and inedible, with pongamia oil representing the inedible oil, and sunflower oil, the edible, are compared on the basis of various physical and chemical properties, NMR and GC analysis, and performance and emission characteristics of the engine on being fuelled by these esters. The results indicate that there is a difference in chemical composition of certain fatty acids which have bearing on the cetane number and shelf life; additionally, there is substantial difference in chemical properties, though the physical properties have similar values; on the performance and emissions front, the edible oil ester is found to be better than inedible oil ester. © 2009 Combustion Institute. All rights reserved.Item Bio-fuel variants for use in CI engine at design and off-design regimes: An experimental analysis(2008) Bekal, S.; Ashok Babu, T.P.A.In this work an attempt has been made to study the ester based fuel variants derived from edible and inedible oil sources for identifying the most appropriate fuel variant and operating mode for running a CI engine based on performance and emission parameters. The twenty four fuel variants tested included esters obtained from the edible sunflower oil, inedible pongamia oil, and their higher and lower proportional blends with diesel. Besides, several other fuel variants obtained from the emulsification of water-in-ester (W/E) with different water proportions have been tested. Basing upon three operational variables, namely, injection timing, injection pressure, and load, comparisons are made in aspects of smoke emissions, NOX emissions, BSEC, and exhaust gas temperatures at the best injection timing. 21.5°, 23°, 24.5° and 27.5° bTDC as the four injection timings and 190, 220 and 250 bar as three injection pressures are considered for the overall study. The 264 sets of experiments conducted with these combinations, focussing on the full and partial load characteristics of the engine, show that both sunflower and pongamia oil esters exhibited similar characteristics in their engine performance, and in both the cases the best BSEC occurred with 220 bar injection pressure for most of the fuel variants, and for straight fuels the ideal injection timing found to be slightly retarded (1.5° crank angle) compared to diesel. However, 24.5° bTDC, normal for the engine, was found to be the most appropriate for the lower blends like B2 (2% ester by volume), B5 and emulsion with 10% water proportion. © 2008 Elsevier Ltd. All rights reserved.Item An analysis of cycle-by-cycle fluctuation in combustion parameter in CI engine operation for various bio-fuels(2011) Bekal, S.; Ashok Babu, T.P.A.The cycle-by-cycle fluctuations in peak pressure of combustion in a CI engine were studied for lower and higher blends of diesel and ester, and water-in-ester emulsions, at four injection timings and three injection pressures using coefficient of variation. The sunflower ester-diesel blends are found to have lower cycle-by-cycle fluctuations than pongemia ester-diesel blends. The fluctuations are found to be higher than that of diesel for higher blend proportions of ester. The water-in-ester emulsion show higher cycle-by-cycle fluctuations than that of ester-diesel blends. In most cases, the Brake specific energy consumption is also found to be higher where the coefficient of variation has higher values. Copyright © Taylor & Francis Group, LLC.Item Fabrication of Zn-Ni alloy coatings from acid chloride bath and its corrosion performance(Center of Excellence in Electrochemistry, Univ. of Tehran ganjali@abechem.com, 2018) Bhat, R.; Bekal, S.; Hegde, A.Optimization of acidic chloride bath containing triethanolamine and citric acid for deposition of a smooth and uniform Zn-Ni alloy coating over mild steel is discussed in the present work. Bath constituents and operating parameters were optimized by standard Hull cell method. Triethanolamine and citric acid were used as additives altered the phase content in the coatings, most likely as a result of their adsorption at the surface of the cathode. The effect of citric acid was more pronounced than that of triethanolamine. The composition of coatings was determined by using colorimetric method. The bath followed anomalous codeposition with preferential deposition of Zn over nobler metal Ni. The experimental results reveal that a bright Zn-Ni alloy coating having ~4.92 wt.%Ni was showing peak performance of the coating against corrosion. Deposition was carried out under different condition of current densities and molar ratio of [Ni +2 ]/[Zn +2 ]. No transition current densities at which codeposition behaviour changed from anomalous to normal type was observed. The cathode current efficiency was higher than 80%. As the current density was increased or the bath temperature was decreased, the concentration of the nobler metal in the coating was increased. The thickness and hardness of all coatings increased as the applied current density was increased. The throwing power and reflectance of the coating was increased with current density to a peak value, and then decreased. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods were used to assess the corrosion resistance of Zn-Ni alloy coatings at different current densities. Surface morphology of the coatings was examined using Scanning Electron Microscopy (SEM). A new and cheap Chloride bath, for bright Zn–Ni alloy coating on mild steel has been proposed, and results are discussed. © 2018 by CEE (Center of Excellence in Electrochemistry).