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Öğe Assessment of hydrogeochemistry and environmental isotopes of surface and groundwaters in the Kiitahya Plain, Turkey(Pergamon-Elsevier Science Ltd, 2017) Berhe, Berihu Abadi; Dokuz, Ugur Erdem; Celik, MehmetThe aim of the present work is to determine the geochemical processes that control the nature of the groundwater and assess the quality of water for drinking and public health purposes. Surface and groundwater samples of Kutahya plain were analyzed for their physio-chemical and environmental isotope properties. The relative concentrations of the water ions were found to occur in the order of Ca2+>Mg2+>(K+ + Na+) and HCO3->SO42->CI-. Piper diagram shows that Ca-Mg/Mg-Ca-HCO3 was the dominant water types. Waters in the area were super -saturated with respect to carbonates. However, they were under -saturated with respect to sulphate minerals. The groundwaters had a mean isotopic composition of -67.32 delta H-2 and- 9.72 delta O-18 and were comparatively lower than surface waters -64.64 delta H-2 and 9.25 delta O-18. Tritium activities in groundwater from the wells ranged from 1.00 to 8.38 TU with a mean value of 4.37 TU. The impact of agricultural practices and poor sanitation conditions is indicated by the positive correlation between K+ - NO3-, K+- NO2- and HCO3- - Cl- ions as well as Na+ and Mg2+ ions with Salon. The groundwater quality of Kutahya plain is influenced by various natural and anthropogenic factors. (C) 2017 Elsevier Ltd. All rights reserved.Öğe Combustion, performance and exhaust emission characteristics of organic based manganese addition to cotton methyl ester(PERGAMON-ELSEVIER SCIENCE LTD, 2016) Celik, MehmetThe interest to diesel engines increases each year due to their high efficiency, better fuel economy and low emission. Thus, the demand for diesel fuel increases in the world each year. Lower fuel consumption and pollutant emissions of internal combustion engines are among basic necessities. Physical and chemical properties of used fuel affect the engine's performance in internal combustion engines, fuel economy and emission characteristics. By the addition of additive in fuel may be improved, the performance, combustion and emission characteristics of fuel. In this study, the engine performance, combustion characteristics and exhaust emissions were examined by adding organic based manganese (Mn) additive on cotton methyl ester (CO) at rates of 4 mu mol/l, 8 mu mol/l, 12 mu mol/l and 16 mu mol/l. The best results were obtained in the C0Mn12 fuel in which 12 mu mol/l additive was added. In fuels in which additive was added, brake specific fuel consumption had decreased while engine torque had increased. Under full load, while maximum decrease in C0Mn12 fuel had been 11.63%, 5.02% and 3.93% respectively compared to C0 fuel for CO, THC and smoke emissions, an increase at a rate of 22.22% had occurred by the C0Mn12 fuel at NOx emissions. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Enhancement performance and exhaust emissions of rapeseed methyl ester by using n-hexadecane and n-hexane fuel additives(Pergamon-Elsevier Science Ltd, 2020) Celik, Mehmet; Bayindirli, CihanA lot of studies were conducted in recent years to improve of biodiesel performance. It has been stated that the addition of additives in biodiesel reduces emissions of unburned hydrocarbon (HC), carbon monoxide (CO) and particulate matter (PM). It makes a significant improvement in thermal efficiency (BTE) and heat dissipation rate (HRR). The additives are attractive in automotive applications due to their excellent phase stability and clean combustion ability. Engine performance and exhaust emissions are mainly based on air-fuel ratio, cetane number, oxygen content of fuel, fuel atomization and the other features. In this study, two different additives were added to the biodiesel to change the number of cetane. In addition, engine performance and emission changes were investigated experimentally. The viscosity and density of fuels were reduced by additives. Compared to R0 fuel, torque increased by 9.74% and 7.22% in RHD20 and RHX20 fuels respectively. While specific fuel consumption decreased by 9.58% and 6.50% respectively. The ignition delay and combustion times decreased due to combustion quality. Maximum cylinder pressure and heat release rate values increased after additives adding in fuels. With the increase of the additive rate, HC (RHD20 23.68%, RHX20 21.05%), CO (RHD20 16.89%, RHX20 15.81%), and soot (RHD20 34.35%, RHX20 26.19%) emissions reduced while NOx (RHD20 2.26%, RHX20 3.21%) emissions increased. (C) 2020 Elsevier Ltd. All rights reserved.Öğe EXAMINATION OF THE EFFECTS OF N-HEPTAN ADDITION TO COTTON METHYL ESTER ON THE ENGINE PERFORMANCE AND COMBUSTION CHARECTERISTICS(GAZI UNIV, FAC ENGINEERING ARCHITECTURE, 2015) Celik, Mehmet; Solmaz, Hamit; Yucesu, H. SerdarThe fuel additives have been studied by many researchers on diesel engine performance and encouraging results have been obtained. During the combustion fuel additives provide the catalyst effect, accelerates the reaction instability and create positive effects on engine performance. In this study; biodiesel was produced by transesterification from the refined cottonseed oil, a certain amount of n-heptane were added in biodiesel and combustion and performance tests were conducted. The experiments was made in a single-cylinder diesel engine at a constant speed and full load. n-heptane added into the cotton methyl ester (PH0) fuel improved the fuel atomization therefore combustion efficiency increased. The maximum power increase was 7.52% in cotton methyl ester fuel containing 8 % n-heptan (PH8). The maximum gas pressure and maximum heat release are formed in almost the same crank angle for all fuels. The 8% n-heptane mixture given the best results in terms of engine performance and combustion characteristics.Öğe EXAMINATION OF THE EFFECTS OF N-HEPTANE ADDITION TO THE CANOLA METHYL ESTER ON ENGINE PERFORMANCE AND COMBUSTION CHARACTERISTICS(TURKISH SOC THERMAL SCIENCES TECHNOLOGY, 2016) Celik, Mehmet; Solmaz, Hamit; Yucesu, H. Serdar; Yilmaz, EmreThe diesel engines are widely used in industries like road transport, railway, agriculture, military, mining, construction, maritime and fixed electricity production for provide the high torque, durability and low fuel combustion. The reduction of oil reserves and strict emission regulations have led many researchers to work on alternative, clean and renewable sources in an effort to reduce greenhouse gases for emissions and to increase the efficiency of internal combustion engines. Among these, biodiesel is one of alternative fuels, and can be used without any changes in the engine. For a better performance of the engine, alternative methods are used by adding different additive substances to the diesel fuel. Because both features of injection systems and quality of injected fuel significantly affect the performance of diesel engine. In this study; refined rapeseed oil was produced from biodiesel by transesterification method, certain n-heptane was added to the produced biodiesel and the engine tests were performed. As a result of these conducted experiments; while maximum torque increase on the fuel KYME-H4 was 3.25%, the maximum power increase was 2.48%. Maximum gas pressure and maximum heat release for all fuel are formed in almost the same crank angle. In the study, 4% n-heptane mixture has given the best results in terms of engine performance and combustion characteristics.Öğe Examination of the effects of organic based manganese fuel additive on combustion and engine performance(ELSEVIER SCIENCE BV, 2015) Celik, Mehmet; Solmaz, Hamit; Yucesu, H. SerdarThe physical and chemical properties of the fuel used in internal combustion engines affect fuel economy and emission characteristics. Various additives are added into diesel fuel in order to improve fuel quality, achieve better combustion and reduce exhaust emissions. Acting as catalyzers during combustion, additives expedite fuel instability reactions and establish positive effects on engine performance. In the present study organic based manganese additive was added into diesel fuel. Combustion, performance and exhaust emission characteristics of the manganese fuel additives were investigated. The tests were carried out in a single-cylinder diesel engine. Among the fuels supplemented with organic based manganese additive, the best results were obtained from 12 ppm mixture rate. In comparison with diesel fuel, the maximum power of the DOMn12 fuel increased by 12.48% while the specific fuel consumption was reduced by 8.17%. At fuel load while CO, THC and smoke emissions were determined to remain at the minimum levels in the fuel DOMn12, NOx emissions reached the maximum level. (C) 2015 Elsevier B.V. All rights reserved.Öğe Exergy, exergoeconomic, and sustainability analyses of a diesel engine using biodiesel fuel blends containing nanoparticles(Pergamon-Elsevier Science Ltd, 2023) Dogan, Battal; Celik, Mehmet; Bayindirli, Cihan; Erol, DervisThe current paper investigated in detail the influence of titanium dioxide (TiO2) and silver oxide (Ag2O) nanoparticles additives into biodiesel fuel obtained from cottonseed oil in terms of performance and emissions. The fuel blends formed by nanoparticles with biodiesel fuel were evaluated from a different perspective with energy, exergy, and exergoeconomic analyses by utilizing the data from the experiments. Thermal efficiency and exergy efficiency increase when nanoparticles were mixed to the biodiesel fuel. Total exergy losses in fuel blends decrease with the nanoparticle additives. When the engine torque was 40 Nm, the total exergy losses for C100, CAg-75, and CTi-75 test fuels were 14.49 kW, 13.91 kW, and 12.17 kW, respectively. The total exergy loss in D100 fuel was calculated as 12.04 kW under the same conditions. The sustainability indexes for D100 and CTi-75 fuels at an engine torque of 40 Nm were 1.626 and 1.620, respectively. Due to the high price of nanoparticles, test fuels with nanoparticles have a higher cost per unit exergy for engine work than pure biodiesel fuel. Hence, it is essential to decrease the cost of nanoparticle production to expand the using of nanoparticle additives in biodiesel.Öğe Experimental Investigation of Effect of n-Hexane Addition in Diesel and Biodiesel Fuels on Performance and Emissions Characteristics(Society of Automotive Engineers Turkey, 2023) Celik, Mehmet; Bayındırlı, Cihan; Kuş, RecaiThe chemical property of fuel seriously affects it’s the spray and atomization. Better atomization contributes to higher efficiency and less exhaust emissions. Fuel characteristics can be improved by addition of additives in the fuel. In this study, n-hexane additive was added in diesel and two different biodiesel fuels. The additive decreased the cetane number, density and viscosity values of the test fuels while increased the lower calorific value. As a result of the experiments, it was seen that there was an increase in the engine torque, engine power and specific fuel consumption by adding additives. Engine torque increased by 1.09% in DHX16 fuel compared to D0 fuel, 5% in RHX16 fuel compared to R0 fuel and 3.29% in CHX16 fuel compared to C0 fuel. The ignition delay decreased with additives and the cylinder pressure increased. The reduction in CO emissions was 7.07% in DHX16 fuel, 12.86% in RHX16 and 12.85% in CHX16 fuel. This decrease in HC emissions was 17.04%, 18.42% and 16.66%, respectively. In terms of NOX emissions, there was an increase of 4.73% in DHX16 fuel mixture compared to D0 fuel, 0.98% in RHX16 fuel mixture compared to R0 fuel and 2.01% in CHX16 fuel mixture compared to C0 fuel due to the improvement of combustion. Copyright 2022 © Universidade de Santiago de Compostela.Öğe Investigation of the effects of organic based manganese addition to biodiesel on combustion and exhaust emissions(ELSEVIER SCIENCE BV, 2016) Celik, Mehmet; Yucesu, H. Serdar; Guru, MetinThe use of biofuel as an energy alternative has gain continuous increase over the years; this is due to their advantage in limiting global warming and harmful emissions arising from diesel engines; this couple with the fast dwindling rate of fossil fuels has increased attention towards their uses. Studies have been conducted in recent years to analyze different energy sources and fuel additives for diesel engines. In this study, the combustion and emission characteristics were investigated by adding organic based manganese additive into rapeseed methyl ester (R0) in four (4) different loads. The results showed that there was a decrease in the viscosity, density, and flash point of fuels treated with additives while the calorific value of the treated fuel was increased. These improvements in the fuel features enhanced the fuel atomization. A minimum ignition delay was obtained in the R0Mn12 fuel for all the loads. A fuel ignition delay of 13.21 degrees CA occurred in the maximum load, while the maximum cylinder pressure of 62.76 bar was recorded. As a result of enhancing the fuel characteristics, analysis of the combustion emission revealed a reduction of 2528% in carbon monoxide (CO), 6.64% in total hydrocarbon (THC), 6.5%.in smoke emission and 25.52% increase of nitrogen oxides (NOx) were recorded in the R0Mn12 fuel compared to the R0 fuel. (C) 2016 Elsevier B.V. All rights reserved.Öğe Investigation of the Performance and Emissions of an Engine Operated with CEO2 Nano Additive Doped Biodiesel(Society of Automotive Engineers Turkey, 2022) Celik, Mehmet; Bayindirli, Cihan; İlhak, M. İlhanThe production of greenhouse gases such as carbon dioxide causes global warming and many other environmental problems. Diesel engines are widely used due to their higher output torque value, better thermal efficiency and durability compared to gaso-line engines. Because of rapid consumption and mitigation of diesel as a fossil fuel, bio-diesel has recently received significant attention as a renewable energy source. There are several sources in order to produce biodiesel. Animal fats, inedible vegetable oils, waste oils and other low-value bioenergy raw materials are suitable sources for biodiesel pro-duction as they are renewable and have no impact on food safety. In this study, CeO2 nano additives at concentrations of 50 ppm and 75 ppm were added to cottonseed based biodiesel. The experiments were conducted at 4 different load conditions on a 3-cylinder water-cooled diesel engine. According to the test results, it was observed that with increasing nano additive concentration, thermal efficiency was increased and spe-cific fuel consumption was reduced. As well as, the results indicated that CO and soot emissions were reduced, while NOx emissions were increased due to the improvement of the combustion performance caused by CeO2 nanoparticles. © 2022 The Author(s).Öğe Multi-objective optimization of a diesel engine fueled with different fuel types containing additives using grey-based Taguchi approach(Springer Heidelberg, 2022) Celik, Mehmet; Bayindirli, Cihan; Mehregan, MinaDue to the reduction of fossil fuels' resources and their contribution to environmental problems, biodiesel fuels have attracted significant attention as substitutes for diesel fuels. However, since their NOx emissions are higher than that of diesel fuels in most cases and also because of their higher viscosity than diesel, fuel additives are used to enhance their properties and reduce emissions. In this study, the effect of n-hexane and n-hexadecane addition to biodiesel and diesel fuels on exhaust emissions and performance of a single-cylinder diesel engine was investigated by using grey-based Taguchi method. Fuel additive, the additive amount, and fuel type were considered as the operating parameters. Three fuel types including diesel, rapeseed oil biodiesel, and cottonseed oil biodiesel were used in this investigation, while n-hexane and n-hexadecane were considered as the two fuel additives. As well as, three levels were assigned to the additive amount which were 4, 8, and 12%. Based on the operating parameters and their levels, the plan of experiments was generated according to L-18 orthogonal array. Using grey relational analysis, this multi-response optimization problem was first transformed into a single response optimization. Then, this single system response, which is known as grey relational grade, was utilized in Taguchi approach for statistical evaluations. The results demonstrated that rapeseed was the best selection for fuel type compared to cottonseed and diesel in order to have the optimum system responses and hexadecane gave better results for system optimization in comparison with hexane additive. As well as, the analysis of variance showed that fuel type was the predominant operating factor influencing the grey relational grade which means fuel type was the most important parameter in the simultaneous optimization of exhaust emissions and engine performance. The Taguchi results also revealed that the optimum condition of engine performance and exhaust emissions happened when engine was fueled with rapeseed biodiesel containing 12% hexadecane as an additive. The confirmation test result validated the reliability of Taguchi approach in this investigation.Öğe Optimizing the thermophysical properties and combustion performance of biodiesel by graphite and reduced graphene oxide nanoparticle fuel additive(Elsevier - Division Reed Elsevier India Pvt Ltd, 2023) Bayindirli, Cihan; Celik, Mehmet; Zan, RecepIn this study, 50 and 75 ppm reduced graphene oxide and graphite nanoparticle additives were added to cottonseed oil methyl ester which was obtained by the trasterification method. The effects of the related nanoparticle additives on fuel properties such as viscosity, lower heating value, density and cetane num-ber were determined, and their effects on engine performance and exhaust emissions were experimen-tally investigated. The superior properties of reduced graphene oxide such as superior conductivity, high reactivity and large surface area to engine performance and emissions were experimentally investigated and presented the in this paper. The results indicated that, brake thermal efficiency increased in NPs additive added fuels by 6.92 % in CGt-50, 11.89 % in CGt-75, 14.35 % in CGn-50 and 17.97 % in CGn-75 fuels, respectively compared to C0 fuel at full load. Brake specific fuel consumptions decreased by 6.92 %, 11.25 %, 13.36 and 16.28 %, respectively. At 8 Nm load, the cylinder pressures of nanoparticle added fuels increased between 1.91 % and 5.16 % compared to base fuel. It was concluded that the heat release rate increased with the increase of the NPs additive ratio. Between the rate of 2 %-5.09 % reducing were obtained in ID, 0.84 %-5.85 % in CD for CGt-75 and CGn75 fuels according to C0 fuel. Compared to C0 fuel, CO emissions decreased by 9.48 %, 11.85 %, 14.23 % and 14.99 %, consecutively, in CGt-50, CGt-75, CGn-50 and CGn-75 fuels at full load. Thanks to the nanoparticle additive, the thermophysical properties and heat transfer rate of the fuels improved and the fuel mixture was stabilized, leading to an improve-ment of 8.98 %, 11.79 %, 14.04 % and 15.73 % in HC emissions, respectively. The NPs additive increased the cylinder temperature by 10.59 %-17.72 %, which enhanced NOx emissions. It was also observed that smoke emissions were reduced by 8.57 %-18.09 %.(c) 2022 Karabuk University. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Öğe The effect of washing process on fuel properties in biodiesel production(SILA SCIENCE, 2012) Celik, Mehmet; Kahraman, Ali; Acaroglu, MustafaThe importance of fuel for world's economy and politics is an undebetable truth. Rapid decrease of world's energy resources made this unrenewable energy resource strategic. Since traditional fossil energy resources are limited and greenhouse gas emissions are becoming a greater concern, research is now being directed towards the use of alternative renewable fuels that are capable of fulfilling an increasing energy demand. One of the more promising approaches is the conversion of vegetable oils (VOs) and other feedstocks, which primarily contain triglycerides (TGs) and free fatty acids (FFAs), into biodiesel.The quality of biodiesel is related to the oil, catalyst type and quantity, methanol's oil/molar rate, reaction heat and time, purity and property of alcahols, production method, quality of washing phase, decomposition of glycerin and store conditions. In this study, raw biodiesel derived from refined cottonseed oil by transesterification has obtained biodiesel by washing with distillated pure water (DW) and deionizationed water (DEW). Physical-chemical properties of biodiesel and the effect of washing processes to the fuel properties are investigated.Öğe The Investigation of Flow Characteristic Around A Bus Model by CFD Method and Improvement of Drag Force by Passive Flow Control Method(Gazi Univ, 2018) Bayindirli, Cihan; Celik, Mehmet; Demiralp, MehmetIn this study, aerodynamic drag coefficient of 1/64 scaled bus model was determined by the Computational Fluid Dynamics (CFD) method. Flow analyzes were performed at 15 m/s, 20 m/s, 25 m/s ye 30 m/s in x direction, between the range of 173000-346000 Reynolds numbers. Flow analysis was made in Fluent (R) program. The aerodynamic drag coefficient (CD) of the bus model was determined as 0.657 on average, the distribution of total drag was determined as pressure-friction based. After the flow visualization, the areas are detected where forms aerodynamic drag on the model bus. A triangular section flow control element has been developed to improve the flow structure and decrease the pressure based drag. The flow control element is an equilateral triangle with a diameter of 15 mm and positioned on the front bumper of the model bus. The aerodynamic drag coefficient of model 1 bus was determined as 0.623. With this passive flow control method, the aerodynamic drag coefficient improved by %5.27. The effect of this improvement on fuel consumption is about 3 % at the high vehicle speed. The effect of this aerodynamic improvement on the annual fuel consumption of a bus has been evaluated.
