Yazar "Tüccar, Gökhan" seçeneğine göre listele

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    A Finite Element Method Study of Polymer Exchange MembraneFuel Cell End Plate Materials by Using Arcan Specimen
    (2021) Avcu, Adem; Tüccar, Gökhan; Choupan, Naghdali
    In the current days, fuel cells are more preferred to generate electricity due to their positive sides. Because, if they use hydrogen andoxygen as fuel, they only produce electricity, heat, and water. This property of fuel cells is significant because it preventsenvironmental and chemical pollution, therefore, they contribute positively to the environment. In addition, they have more positiveaspects such as having no moving or rotating parts. Therefore, they don’t require mechanical maintenance and don’t make noise.Besides, they can be used in a wide range of areas as mobile and stationary power sources for electricity generation. There are manyfuel cell types but proton exchange membrane fuel cell (PEMFC) is more common than the other fuel cell types. It consists of partssuch as an endplate, bipolar flow plate, gas diffusion layer, catalyst layer, and membrane. End plates are located on the outer side ofPEMFC and hold together its stacks. In the design of the endplates, the state of fracture energy should be considered in differentloading conditions. Because the material may fail if it is designed only for the strength of materials concepts. In this paper, pure modeI, pure mode II and mixed mode fracture energy behavior of different materials were investigated numerically by using Arcanspecimen.
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    A Numerical Investigation of The Fracture Energy of Materials for Fuel Cell End Plates
    (2021) Avcu, Adem; Choupan, Naghdali; Tüccar, Gökhan
    Nowadays, with increasing energy requirements, the use of clean energy resources has become important. Fuelcells are an important key for clean energy technology due to wide range of utilization areas such as automotive,portable power applications, electricity generation, space, aviation and naval technologies. Additionally, theyhave many significant properties such as not producing harmful gases, therefore they do not cause environmental and chemical pollution. Besides, they have not any moving parts, also they do not produce noise. Bycomparison to fossil fuel, fuel cells have high efficiency that reaches up to 60% in appropriate conditions. ProtonExchange Membrane Fuel Cell (PEMFC) has many advantages than other fuel cell types due to simple structure,higher efficiency and low operating temperature. PEMFC may consist of one or more stacks to generate moreelectricity. End plate of PEMFC holds together all parts of it. Therefore, the material selection for end plate isimportant to provide safe conditions. To use PEMFC safely, investigation of material fracture energy is requiredto decide that the material is in safe conditions or not. There are three fracture energy modes which are mode I,mode II and mode III. There are many methods to investigate failure of material at different modes. Unlike othermethods, Arcan specimen gives facility to evaluate of mode I, mode II and mixed modes. The main purpose ofthis paper was to compare the results of fracture energy (stain energy release rate) of different materials for endplates in fuel cells. Another goal was to select a suitable material was selected as PEMFC end plate.
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    COMPARISON OF TRAFFIC DENSITIES AT DIFFERENT SIGNALIZATION TIMINGS IN ROUNDABOUTS
    (2018) Uludamar, Erinç; Tüccar, Gökhan
    The increasing number of vehicles triggers traffic jam which is one of the most important problems that occursin crowded cities. Signalization timing has a crucial role in controlling traffic flow and decreasing loss of time incity traffic. In order to reduce queue length and vehicle delays in traffic, the estimation of traffic concentration atdifferent signalization timings plays an important role. Traffic simulation tools such as RODEL, SIDRA, andVISSIM are used to understand the behavior of vehicles in traffic. In this study, VISSIM program was used todemonstrate queue lengths, vehicle delays and vehicular emission formations in a roundabout at differentsignalization timings. The study has been evaluated on a real case study to verify the differences between currentand proposed states. A roundabout in Adana (Turkey) was selected which is located at the city center with oversaturated traffic density for a case study. The model indicated that increment of the green time period of thesouth road from 22 seconds to 28 seconds resulted in improved queue lengths, vehicle delays and emissionformations of the vehicles which were around the roundabout.
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    Design and Analysis of Hydraulic Truck Unloading Platforms
    (2017) Uludamar, Erinç; Tüccar, Gökhan
    Dampersiz kamyonların yükünün boşaltılmasının en verimli yolundan birisi Hidrolik Kamyon Boşaltma Platformlarının (HKBP) kullanılmasıdır. HKBPler dizayn edilirken platformun güvenilirliği ve malzeme maliyeti göz önünde alınmalıdır. Bu sebeple, bu çalışmada, üç farklı HKBP tasarımı farklı operasyon pozisyonlarındaki gerilme dağılımları ve maliyeti düşünülerek karşılaştırılmıştır. CATIA V5 ve ANSYS Workbench yazılım programları üç boyutlu modellerin hazırlanması ve bu modellerin gerilme analizleri için kullanılmıştır. Yapısal analiz sonuçları en yüksek von-Mises gerilme dağılımlarının 93,41 MPa ve 210,29 MPa arasında olduğunu göstermiştir. Yapıda kullanılan malzemeler gerilme dağılımlarına göre seçilmiştir. Malzeme maliyeti karşılaştırılmış ve sonuçları da sunulmuştur. Ayrıca platform yapısının von-Mises gerilmelerinin yatay pozisyonda 45o eğik pozisyona göre daha yüksek olduğu bulunmuştur
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    Diesel engine vibration analysis using artificial neural networks method: Effect of NH3 additive in biodiesels
    (Elsevier Ltd, 2024) Raja Ahsan Shah, Raja Mazuir; Böyükdipi, Ömer; Tüccar, Gökhan; Al-Otoom, Awni; Soyhan, Hakan Serhad
    Diesel engine parameters, such as fuel and its additives, play an essential role in minimising the effects of engine vibration. This study aimed to use artificial neural networks (ANN) to model and analyse diesel engine vibration characteristics at different engine speeds using NH3 as an additive in hazelnut (HD), peanut (PD), and waste-cooking oil (WD) biodiesels. The results showed good correlations between the ANN models and experimental results using regression analysis methods. The ANN models for diesel engines showed high accuracy. The ANN models indicated that a 5 % NH3 additive decreased engine vibration for HD and PD. In comparison, 10 % and 15 % NH3 additive ratios increased engine vibration for HD, PD, and WD due to low combustion quality. The lowest vibration levels occurred with P100, P95A5, P90A10, and P85A15 at 1200 rpm. H100 and H95A5 produced the highest diesel engine resultant vibration (DERV) values. All ANN models generated the lowest and highest DERV values at 1200 rpm and 2100 rpm, respectively. The RMS method showed that H95A5, P85A15, and W85A15 contributed the most to diesel engine vibration. Using a low amount of NH3 additive positively affected DERV for HD and PD but not for WD. © 2024
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    Dizel motorlarda alternatif yakıt olarak karpuz çekirdeği biyodizelinin değerlendirilmesi
    (2017) Abdulvahitoğlu, Aslı; Tüccar, Gökhan
    Petrolün tükenmesi bilim adamlarını yeni enerji kaynaklarını araştırmaya itmiş ve biyodizel yenilenebilirkaynaklardan elde edilebilir olmasından dolayı en popüler alternatif yakıtlardan biri haline gelmiştir. Bu çalışmanın amacı, dizel motorlarda alternatif yakıt olarak karpuz çekirdeği yağı biyodizel (KÇB)kullanılabilirliğini değerlendirmektir. Bu çalışmada, KÇB ve KÇB20 (hacimsel olarak %80 dizel ile %20KÇB) yakıt karışımının fiziksel yakıt özelliklerine bakılmıştır. Ölçülen fiziksel yakıt değerleri, yoğunluk,setan sayısı, viskozite akma noktası ve parlama noktasıdır. Buna ek olarak, test yakıtları dizel motordaKÇB kullanımının motor performans parametreleri, azot oksitler ve karbon monoksit gibi, egzoz emisyonları üzerindeki etkilerini değerlendirmek amacıyla test edilmiştir. Motor performansı deneyleri sonuçlarına göre; KÇB kullanımıyla test motorunda tork ve fren güç değerlerinin biraz azaldığı, emisyondeğerlerinin ise KÇB kullanımı ile düzeldiği gözlemlenmiştir. Bu nedenle, karpuz çekirdeği yağı esteriçevre dostu yanma profiliyle alternatif dizel yakıt katkısı olarak tavsiye edilmektedir.
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    Investigations of Effects of Density and Viscosity of Diesel and Biodiesel Fuels on NOx and other Emission Formations
    (2018) Tüccar, Gökhan; Tosun, Erdi; Uludamar, Erinç
    In the present study, effects of fuel properties; such as viscosity and density of different biodiesels on engine exhaust emissions were investigated. Sunflower, corn and canola oils were used as raw materials of biodiesel fuels which were produced via transesterification method. In experiments, pure biodiesels were used as test fuels and diesel was used as reference fuel. The results indicated that viscosity and density of biodiesel fuels went up with a higher proportion of biodiesel. Engine experiments, which were conducted on a Mitsubishi Canter 4D34-2A, four-stroke, four-cylinder diesel engine indicated that carbon monoxide (CO) emission reduced with the utilization of fuels that have higher viscosity and density. On the other hand, carbon dioxide (CO2) and nitrogen oxide (NOx) emission had opposite trend. Both emission values were increased with higher biodiesel ratios.
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    Numerical Investigation of Effects of Different Injection Pressure on Diesel Engine Performance and NOX Emission
    (2021) Avcu, Adem; Tüccar, Gökhan; Choupanı, Naghdali
    Favourable efficiency of diesel engines makes them the most abundant type of internal combustion engines. However, diesel engines are also primary sources of particulate matter (PM) and nitrogen oxides (NOX) emissions formed as a result of the combustion process. There are many variables to affect the performance of diesel engine. One of them is injection pressure. Combustion process has a crucial effect on emission formation of diesel engines and this process is highly affected by fuel atomization. Injectors are one of the most important components of diesel engines that control the atomization of fuel. Today’s modern injectors provide high injection pressures to improve fuel atomization. To reduce exhaust emissions and fuel consumption, the effect of high-pressure fuel injection was investigated in fourcylinder engines numerically. Increased injection pressure improves smoke and fuel consumption, especially at low and medium speeds. However, some variables can be adversely affected by pressure increases. In this study, variables affecting engine performance were observed at different injection pressures for 500-800 bar and 800-1000 bar, and the results were shared.