The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Arian Bisha - One of the best experts on this subject based on the ideXlab platform.
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Gas escape to crankcase: impact of system parameters on sealing behavior of a piston cylinder ring pack
International Journal of Energy and Environmental Engineering, 2019Co-Authors: Cristiana Delprete, Erjon Selmani, Arian BishaAbstract:Internal combustion engines are the generators of energy for many transportation applications, but they still have an overall low efficiency due to mechanical and thermal losses. The combustion chamber is the core element of the engine and it ought to be perfectly sealed; however, some of the gas leaks toward the crankcase due to imperfect sealing of the rings. This leakage is known as blow-by and affects efficiency, correct lubrication and emissions. The aim of this paper was to understand, in a more detailed way, how some parameters could affect the sealing efficiency of a ring pack. In particular, ring gaps, ring masses and elastic properties, and ring static twists, were varied from the original and investigated for their influence on the inter-ring dynamics and sealing efficiency. The problem, referred to a turbo diesel engine, was formulated in terms of motion equations for the rings and gas equations for the inter-ring crevices, and solved in ^©Ricardo RINGPAK solver. The results were compared with the original design and with the reference literature. These results confirm that ring gaps and ring unstable motion have an important role in the phenomenon of gas blow-by. In addition, the second ring emerged to have a more important role on the blow-by reduction with respect to the top ring. However, this phenomenon is complex due to the interaction of several parameters, not all of which were included in this study. Nevertheless, these findings can already be taken into account for further studies or experimental investigations.
Pranesh B Aswath - One of the best experts on this subject based on the ideXlab platform.
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Impact of Diesel Engine Oil Additives–Soot Interactions on Physiochemical, Oxidation, and Wear Characteristics of Soot
2019Co-Authors: Kimaya Vyavhare, Mihir Patel, Sujay Bagi, Pranesh B AswathAbstract:Carbonaceous soot accumulated in crankcase oil is known to have an adverse effect on diesel engine performance, durability, and fuel efficiency. The current study is focused on determining the influence of engine oil additive package and soot interactions on crankcase soot chemistry, structure, and oxidation. The soot was extracted from the crankcase oil of Mack T-12 dynamometer diesel engine tests and characterized using X-ray absorption near edge structure (XANES) spectroscopy, high-resolution transmission electron microscopy (HR-TEM), high-temperature X-ray diffraction (HT-XRD), and energy dispersive spectroscopy (EDS). Additionally, four-ball wear bench tests were conducted to study the effect of several interactions like antiwear additive–soot, dispersant–soot on lubricity of formulated engine base oils. XANES and HR-TEM analyses suggest the presence of chemical compounds originating from engine oil chemistry as either adsorbed/embedded into the turbostratic nanostructure of soot. The HT-XRD method was employed to map variations in interplanar spacing of basal plane (002) of turbostratic soot with temperature, indicative of the degree of disorder and ease of oxidation. The oxidative reactivity of crankcase soot is found to be strongly dependent on the changes in the physical and chemical makeup of carbonaceous soot structure. Wear assessment proved that the increase of soot concentration in formulated oils significantly increases wear of sliding surfaces. Results indicate that the soot-induced wear occurs through an abrasive wear mechanism, where soot antagonistically interacts with protective antiwear additive-formed tribofilms and exacerbate wear of engine components
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structure and chemistry of crankcase and cylinder soot and tribofilms on piston rings from a mack t 12 dynamometer engine test
Tribology International, 2014Co-Authors: Mihir Patel, Pranesh B AswathAbstract:Structure and chemistry of soot extracted from the crankcase and cylinder wall and tribofilms on piston rings of a Mack T-12 engine test were examined. XANES spectra recorded on soot samples indicate the presence of thermo-oxidative and tribochemical decomposition products in engine oil indicative of interaction between piston ring and soot samples. HRTEM indicates the presence of nanoparticles of calcium phosphate compounds, ZnO and Fe2O3 embedded at the surface of the turbostratic soot structure possibly responsible for third body wear. Abrasive grooves were found on the piston ring indicative of abrasive wear mechanism as a dominant wear phenomenon. In addition, significant differences in chemical composition of crankcase soot, cylinder soot and piston ring tribofilms were elucidated.
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morphology structure and chemistry of extracted diesel soot part i transmission electron microscopy raman spectroscopy x ray photoelectron spectroscopy and synchrotron x ray diffraction study
Tribology International, 2012Co-Authors: Mihir Patel, Cristy Leonor Azanza Ricardo, P Scardi, Pranesh B AswathAbstract:Inclusion of soot in lubricating oil can result in increased wear and decreased lubricity. In this study we have attempted to gain fundamental insight into the morphology, structure and chemistry of diesel soot. Energy dispersive spectroscopy using TEM suggests interaction between lubrication additives and crankcase soot resulting in the presence of C, Ca, S, P, O and Zn. Synchrotron X-ray diffraction indicates the presence of different sulfates of calcium as well as the presence of amorphous zinc based compounds. Raman spectroscopy and selected area diffraction using TEM indicates that the turbostratic structures of the carbon in both are very similar.
Cristiana Delprete - One of the best experts on this subject based on the ideXlab platform.
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Gas escape to crankcase: impact of system parameters on sealing behavior of a piston cylinder ring pack
International Journal of Energy and Environmental Engineering, 2019Co-Authors: Cristiana Delprete, Erjon Selmani, Arian BishaAbstract:Internal combustion engines are the generators of energy for many transportation applications, but they still have an overall low efficiency due to mechanical and thermal losses. The combustion chamber is the core element of the engine and it ought to be perfectly sealed; however, some of the gas leaks toward the crankcase due to imperfect sealing of the rings. This leakage is known as blow-by and affects efficiency, correct lubrication and emissions. The aim of this paper was to understand, in a more detailed way, how some parameters could affect the sealing efficiency of a ring pack. In particular, ring gaps, ring masses and elastic properties, and ring static twists, were varied from the original and investigated for their influence on the inter-ring dynamics and sealing efficiency. The problem, referred to a turbo diesel engine, was formulated in terms of motion equations for the rings and gas equations for the inter-ring crevices, and solved in ^©Ricardo RINGPAK solver. The results were compared with the original design and with the reference literature. These results confirm that ring gaps and ring unstable motion have an important role in the phenomenon of gas blow-by. In addition, the second ring emerged to have a more important role on the blow-by reduction with respect to the top ring. However, this phenomenon is complex due to the interaction of several parameters, not all of which were included in this study. Nevertheless, these findings can already be taken into account for further studies or experimental investigations.
O M I Nwafor - One of the best experts on this subject based on the ideXlab platform.
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the effect of elevated fuel inlet temperature on performance of diesel engine running on neat vegetable oil at constant speed conditions
Renewable Energy, 2003Co-Authors: O M I NwaforAbstract:The concept that engine design is all important in the use of vegetable oils as a diesel fuel has been pointed out by many researchers. One hundred percent of vegetable oil can be used safely in an indirect injection engine, but not in a direct injection engine due to the high degree of atomization required for this type. This problem is related to increasing droplet size on injection into the cylinder that results in poor combustion. This in turn, causes the formation of deposits in the combustion chamber, together with oil dilution due to introduction of unburnt fuel into the crankcase. The objective of this work was to evaluate the effect of increasing fuel inlet temperature on viscosity and performance of a single cylinder, unmodified diesel engine. The overall results showed that fuel heating increased peak cylinder pressure and was also beneficial at low speed and under part-load operation. The high combustion temperature at high engine speed becomes the dominant factor, making both heated and unheated fuel to acquire the same temperature before fuel injection.
Albert U C Maduako - One of the best experts on this subject based on the ideXlab platform.
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assessment of oxidation in automotive crankcase lube oil effects of metal and water activity
Industrial & Engineering Chemistry Research, 2002Co-Authors: Felix Egharevba, Albert U C MaduakoAbstract:The changes in oxidation stability of two grades of crankcase lube oil, monograde (SAE 40) and multigrade (SAE 20W50), and their base oils were monitored by measuring their carbonyl peak index with respect to time in order to corroborate the results of sludge deposit and soluble acidity characteristics. The carbonyl peak index was calculated as the difference in the ratios of the absorbance of the carbonyl band at 1700 cm-1 and of the basic peak methyl stretching vibration at around 3000 cm-1 at oxidation time t and the start of the experiment. The results showed that the base oils were oxidized to a greater extent than the formulated oils. The monograde oil and its base oil had higher carbonyl peak indexes than their respective multigrade counterparts, showing that the monograde oils were less resistant to oxidation than the multigrade oils. However, results of sludge deposits and soluble acidity showed that the multigrade oils formed more oxidation products than the monograde oils, which also incidental...