Faculty Publications
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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 Evaluation of combustion, performance and emissions of a diesel engine fueled with bio-fuel produced from cashew nut shell liquid(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2015) Dinesha, P.; Mohanan, P.Presently, energy security and food security are two major problems of developing countries. The use of edible oils as an alternative fuel for internal combustion may lead to a food crisis. The non-edible plant-based alternative fuel not only results in energy security but also helps to keep the environment free from pollution. In this experimental investigation, a non-edible plant-based bio-fuel cardanol produced from cashew nut shell liquid (CNSL) is used to study the combustion, performance and emissions of a single-cylinder diesel engine. The test conditions of the engine are 200 bar injection pressure and 27.5 degree bTDC injection timing. The bio-fuel blends B10M10 (10% cardanol + 80% diesel + 10% methanol), B20M10, and B30M10 (30% cardanol + 60% diesel + 10% methanol) were tested at 25%, 50%, 75%, and full load conditions. The results were compared with baseline diesel operation. From the experimental work, it was observed that the brake thermal efficiency of B10M10 and B20M10 (20% cardanol + 70% diesel + 10% methanol) is comparatively similar to that of diesel. The lower emissions of CO, hydrocarbon, and smoke are encouraging to recognize B20M10 as an optimized fuel blend for a compression ignition engine at 200 bar injection pressure and 27.5 degree bTDC. The significant factors of cardanol bio-fuel include its low cost, non-edible, abundance, and it is a by-product of the cashew nut industries. © © 2015 Taylor & Francis.Item Enhancing the ignition, hardness and compressive response of magnesium by reinforcing with hollow glass microballoons(MDPI AG Postfach Basel CH-4005, 2017) Manakari, V.; Parande, G.; Doddamani, M.; Gupta, M.Magnesium (Mg)/glass microballoons (GMB) metal matrix syntactic foams (1.47-1.67 g/cc) were synthesized using a disintegrated melt deposition (DMD) processing route. Such syntactic foams are of great interest to the scientific community as potential candidate materials for the ever-changing demands in automotive, aerospace, and marine sectors. The synthesized composites were evaluated for their microstructural, thermal, and compressive properties. Results showed that microhardness and the dimensional stability of pure Mg increased with increasing GMB content. The ignition response of these foams was enhanced by -22 °C with a 25 wt % GMB addition to the Mg matrix. The authors of this work propose a new parameter, ignition factor, to quantify the superior ignition performance that the developed Mg foams exhibit. The room temperature compressive strengths of pure Mg increased with the addition of GMB particles, with Mg-25 wt % GMB exhibiting the maximum compressive yield strength (CYS) of 161 MPa and an ultimate compressive strength (UCS) of 232 MPa for a GMB addition of 5 wt % in Mg. A maximum failure strain of 37.7% was realized in Mg-25 wt % GMB foam. The addition of GMB particles significantly enhanced the energy absorption by -200% prior to compressive failure for highest filler loading, as compared to pure Mg. Finally, microstructural changes in Mg owing to the presence of hollow GMB particles were elaborately discussed. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.Item Influence of spark timing on the performance and emission characteristics of gasoline–hydrogen-blended high-speed spark-ignition engine(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2017) Shivaprasad, K.V.; Chitragar, P.R.; Nayak, V.; Kumar, G.N.This article experimentally investigates the effect of spark timing on performance and emission characteristics of high-speed spark-ignition (SI) engine operated with different hydrogen–gasoline fuel blends. For this purpose, the conventional carbureted SI engine is modified into an electronically controllable engine, wherein an electronically controllable unit was used to control the ignition timings and injection duration of gasoline. The tests were conducted with different spark timings at the wide open throttle position and 3000 rpm engine speed. The experimental results demonstrated that brake mean effective pressure and engine brake thermal efficiency increased first and then decreased with the increase in spark advance. Peak cylinder pressure, temperature and heat release rate were increased until 20% hydrogen addition and with increased spark timings. NOx emissions were continuously increased with the increment in both spark timings and hydrogen addition, whereas hydrocarbon emissions were increased with spark timings but decreased with hydrogen addition. CO emissions were reduced with the increase in spark timing and hydrogen addition. © 2016 Informa UK Limited, trading as Taylor & Francis Group.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 Optimized ANN-GA and experimental analysis of the performance and combustion characteristics of HCCI engine(Elsevier Ltd, 2018) Anarghya, A.; Rao, N.; Nayak, N.S.; Tirpude, A.R.; Harshith, D.N.; Samarth, B.R.HCCI (Homogeneous Charge Compression Ignition) engine has the benefit of operating at high thermal efficiency and low emissions of NOx and soot. However, it has challenges of complex combustion phase controlling and low operating range. This research work investigated the performance and combustion characteristics of HCCI engine with numerical simulations on ANSYS FLUENT and neural network models. The numerical and neural network results were validated by experimental observations with different fuel properties and reduced valve lifts for trapping of the exhaust gases. Experiments were performed on a SMART engine for different speeds and inlet air temperature, with various reference fuels (PRF30, PRF50, PRF70) and methanol to validate the CFD and ANN-GA observations. The engine performance was analyzed for IMEP, ISFC and thermal efficiency, which were found to be 8.2 bar, 205 g/kWh and 44.5% respectively as the optimum performance with PRF-70 fuel. The trapping of the residual gases was performed with various fuel blends in order to overcome the cyclic variations and to improve the operating zones near the knock boundary. The heat release rate was significantly reduced with trapped exhaust gases, and operating region was improved with the use of methanol fuel. Overall the trapping of the hot residual gases resulted in the maximum increase in the operating region by 12% and reduced cyclic variations by 15% for methanol fuel. The exhaust emissions were analyzed and ultra-low emissions of NOx at lean operating conditions were observed with the reduced valve lifts. The study results indicated thermal NO emissions on an average were decreased by 7.8%, CO emissions reduced by 6% and HC emissions increased by 9%. Methanol had ultra-low emissions of HC and CO, but higher emissions of NO and PRF30 had lower emissions of NO. However, ANN-GA model gave satisfactory combustion characteristics and emissions with respect to experimental results. Thus, CFD simulations, Neural Network methods and experimental study gave valuable thoughts of trapped residual gases approach on performance, combustion and emission characteristics of HCCI with PRF's and methanol fuel. © 2017 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 An investigation on CRDi engine characteristic using renewable orange-peel oil(Elsevier Ltd, 2019) Bragadeshwaran, B.; Kasianantham, K.; Arumuga Perumal, D.A.; Babu, J.M.; Tiwari, A.; Sharma, A.Aiming towards discovering a solution for the imminent fossil fuel crisis, the research contributes towards the utilisation of orange peel oil as a potential alternative to mineral diesel while strictly adhering to the emission norms. The study reveals the performance, combustion and emissions characteristics obtained upon operating a 20% by volume of OPO blended with diesel, in a compression ignition engine, integrated with a common rail direct injection (CRDi) system. The fuel injection pressures were varied as 400 bar, 500 bar and 600 bar. Furthermore, two stage injection strategies were employed while varying the pilot charge quantity as 10%, 20% and 30%. Subsequently, 10% EGR was employed for the test with 30% pilot injection quantity upon realising that the respective NOx emissions were the highest for the same. All the results were compared with the test results while utilising diesel at 600 bar injection pressure. For OPO20 the brake thermal efficiency at full load was observed to be 31.37% higher and the brake specific fuel consumption 5.53% lower than that for diesel. In-cylinder pressure values recorded were almost similar to diesel corresponding to brake power. Heat release rate was significantly higher in case of orange peel oil. Additionally, it was found that smoke, unburned hydrocarbons content and carbon monoxide emission decreased by 16.30%, 27.63% and 42.28% respectively in the engine exhaust. Oxides of nitrogen were recorded to be 15.46% higher than that of diesel. © 2018 Elsevier LtdItem 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.Item Consequences of ignition timing on a hydrogen-fueled engine at various equivalence ratio(Taylor and Francis Ltd., 2022) Pandey, J.K.; Gottigere Narayanappa, K.The energy crisis in the transportation sector directs researchers to look for renewable alternative energy sources. Among all available, hydrogen is one of the prominent contenders that can be renewed and available on a large scale and is carbon-free. The study suggests hydrogen is a better fuel for SI engines than CI engines. However, its feasibility still needs to be investigated. In the present experimental study, a hydrogen-fueled SI engine is tested for various equivalence ratios (ϕ) and ignition timing (IT) at a compression ratio (CR) of 14:1. The outcomes show that the brake thermal efficiency (BTE) increases by 1.07% with increasing ϕ, while a slightly retarded IT exhibits the best figure. There is an average 1.42% increase per ϕ from gasoline noticed at ϕ 0.6, which increased to 2.12% at ϕ 0.8. The cylinder pressure and net heat release rate improve and advance with retarding IT and increasing ϕ. The flame development period (CA10) continuously reduces with increasing ϕ by an average 1.93%/ϕ change and retarding IT by 2.17%/2°CA ignition retard, due to increased mass of hydrogen and increased cylinder temperature. While flame propagation period (CA10-90) reduces with increasing ϕ and reduces to a minimum with retarding IT and then increase. The maximum cylinder temperature (Tmax) and exhaust gas temperature (EGT) increase with increasing ϕ by 3.28% and 3.62%, respectively, while Tmax reduces with retarding IT, resulting in a reduction in NOx emission. The EGT increases with retarding IT. The NOx emissions increase with ϕ by an average of 4.72%; however, at higher ϕ = 0.8, the NOx emissions are 2.51% lower than gasoline for most of the retarded IT. At a retarded IT, hydrogen performs similarly to gasoline at moderate NOx emissions. The high CR helps reduce volumetric losses reflected in BTE, found above gasoline despite less fuel energy supplied than gasoline. Although NOx emissions are controlled by retarding IT, an efficiently controlling IT resulted in a severe drop in BTE. © 2022 Taylor & Francis Group, LLC.