83 research outputs found
Optimizing soybean biofuel blends for sustainable urban medium-duty commercial vehicles in India: an AI-driven approach
This article presents the outcomes of a research study focused on optimizing the performance of soybean biofuel blends derived from soybean seeds specifically for urban medium-duty commercial vehicles. The study took into consideration elements such as production capacity, economics and assumed engine characteristics. For the purpose of predicting performance, combustion and emission characteristics, an artificial intelligence approach that has been trained using experimental data is used. At full load, the brake thermal efficiency (BTE) dropped as engine speed increased for biofuel and diesel fuel mixes, but brake-specific fuel consumption (BSFC) increased. The BSFC increased by 11.9% when diesel compared to using biofuel with diesel blends. The mixes cut both maximum cylinder pressure and NOx emissions. The biofuel-diesel fuel proved more successful, with maximum reduction of 9.8% and 22.2 at rpm, respectively. The biofuel and diesel blend significantly improved carbon dioxide (CO2) and smoke emissions. The biofuel blends offer significant advantages by decreeing exhaust pollutants and enhancing engine performance
Microscopic characteristics of biodiesel – Graphene oxide nanoparticle blends and their Utilisation in a compression ignition engine
Use of nano-additives in biofuels is an important research and development topic for achieving optimum engine performance with reduced emissions. In this study, rice bran oil was converted into biodiesel and graphene oxide (GO) nanoparticles were infused into biodiesel-diesel blends. Two blends containing (i) 5% biodiesel, 95% diesel and 30 ppm GO (B5D95GO30) and (ii) 15% biodiesel, 85% diesel and 30 ppm GO (B15D85GO30) were prepared. The fuel properties like heating value, kinematic viscosity, cetane number, etc. of the nanoadditives–biodiesel-diesel blends (NBDB) were measured. Effects of injection timing (IT) on the performance, combustion and emission characteristics were studied. It was observed that both B15D85GO30 and B5D95GO30 blends at IT23° gave up to 13.5% reduction in specific fuel consumption. Compared to diesel, the brake thermal efficiency was increased by 7.62% for B15D85GO30 at IT23° and IT25°. An increase in IT from 23° to 25° deteriorated the indicated thermal efficiency by 6.68% for B15D85GO30. At maximum load condition, the peak heat release rates of NBDB were found to be lower than the pure diesel at both IT. The CO, CO2 & NOx emissions were reduced by 2–8%. The study concluded that B15D85GO30 at IT23° gave optimum results in terms of performance, combustion and emission characteristics
Analysis for the resilience modeling in implications of climate mitigation incorporated with the nuclear energy
Characterızatıon Of Polypropylene Materıal For Carbondıoxıde Cell Productıon
Bu tez çalışması, Tübitak 115M041 numaralı ve Yüksek Isıl Dirençli Genleştirilmiş Perlit Esaslı ve Karbondioksit Hücreli Isı Yalıtım Levhasının Geliştirilmesi başlıklı projenin bir iş paketi kapsamında gerçekleştirilmiştir. Projenin özgün yanını oluşturan karbondioksit hücreleri polimer esaslı kap içerisine CO2 gazı hapsedilerek oluşturulmakta ve ana matriste yapay gözenek oluşturmak için kullanılmaktadır. CO2 hücrelerini saran polimer kap malzemesi olarak ısı iletim katsayısı düşük, Petkim tarafından yerli olarak üretilebilen ve gaz geçirgenliği kabul edilebilir seviyede olan Poliproilen (PP) malzemesi seçilmiştir. Bu tez çalışmasında PP malzemesinin polimer kap olarak en ince kalınlıkta üretilebilirliğine yönelik reolojik karakterizasyonu yapılmıştır. Bu kapsamda, 115M041 numaralı proje bütçesiyle alınan ekstrüder makine için farklı L uzunluğunda (10, 15, 20 ve 30 mm) ve D çapında (1 ve 2 mm) 6 adet kapileri kalıp üretilmiştir. Üretilen kapileri kalıplar ile tek vidalı ekstrüder makineler için kapileri reometre düzeneği kurulmuştur. Kurulan düzenek ile PP malzemesi için kayma hızı değerleri 350-46,000 s-1 aralığında elde edilmiştir. Elde edilen sonuçlar, kalıp çapının artması ile kayma gerilmesi ve viskozite değerlerinin yükseldiğini kayma hızı değerinin ise azaldığını, kalıp uzunluğunun artmasıyla kayma gerilmesi ve viskozite değerlerinin azaldığı göstermiştir.This thesis study was undertaken within a work package of Tübitak Project with 115M041 number entitled Development of high thermal resistant, expanded perlite based thermal insulation panel with CO2 cell. Carbon dioxide cells, which are the unique side of this project, are formed by trapping CO2 gas in a polymer-based membrane and the main matrix is used to form artificial pores. Polypropylene (PP) material, which has a low thermal conductivity coefficient and which can be produced locally by Petkim and is in an acceptable gas permeability level, has been selected as the polymer membrane material surrounding the CO2 cells. In this thesis study, rheological characterization of PP material as polymer membrane in the thinnest thickness was made. Within this scope, 6 dies with different L lengths (10, 15, 20 and 30 mm) and D diameters (1 and 2 mm) were manufactured for the extruder machine which were bought by the project budget numbered 115M041. With manufactured capillary dies, capillary rheometer contrivance was installed for single screw extruder machines. With installed contrivance, the shear rate values for PP material was obtained at the range of 350-46,000 s-1. The results showed that the shear stress and viscosity values increased as the die diameter increased, the shear rate decreased as the die length increased, and the shear stress and viscosity values decreased as the die length increased
Turkey's electricity generation problem and nuclear energy policy
Agbulut, Umit/0000-0002-6635-6494WOS: 000465726800001Energy is undoubtedly the most key to sustainability of the economic growth of a country. Turkey is today dependent on energy approximately at a rate of 75%. The country is able to meet approximately half of its total electricity demand owing to its own limited resources. Over the past 10 years period, Turkey paid nearly half a trillion dollars for its energy bill. On the other hand, the official reserve assets are equal to 93 billion dollars in the central bank of Turkey in November 2018. New power plants are being installed and planned to decrease the energy dependency in the country, particularly for electricity generation. Of these plants, nuclear energy is currently one of the newest and the most debated issues for the country. Hence, this study mainly focused on the possible outputs of the transiting to nuclear energy such as carbon dioxide emissions, radiation doses, energy demand, economic growths, etc., in the country. Additionally, new shares on electricity generation by the new sources were foreseen with this study after the nuclear plants to be operated in Turkey
Approximation by complex kantorovich-schurer polynomials in compact disks
Bu tezde kompakt disklerde analitik fonksiyonlara ilişkin kompleks Bernstein- Schurer ve Kantorovich-Schurer polinomlarının yaklaşım özellikleri incelendi.
Bu operatörler için eş anlı yaklaşım mertebesi ve Voronovskaja tip teoremler verildi. Böylelikle Bernstein-Schurer polinomlarının yaklaşım özellikleri reel aralıklardan kompleks düzlemin kompakt disklerine genişletildi.In this thesis, the approximation properties of complex Bernstein-Schurer and Kantorovich-Schurer polynomials attached to analytic functions on compact disks are investigated. The order of simultaneous approximation and the Voronovskaja-type theorems for these operators are given. Hence the approximation properties of Bernstein-Schurer polynomials from real intervals to compact disks in the complex plane are extended
Investigation the effects of adding hybrid nanoparticle on performance, combustion and emission characteristics of a diesel engine
YÖK Tez No: 673175Bu tez çalışmasında, mono ve hibrit nanopartikül kullanımının bir dizel motorun yanma, performans ve emisyon karakteristikleri üzerindeki etkilerinin araştırılması amaçlanmıştır. Bu bağlamda, üç farklı nanopartikül tipi (Al2O3, bN ve CuO) ve bunların ikili hibrit formları (CuO-Al2O3, bN-CuO ve bN-Al2O3) geleneksel dizel yakıt ile ultrasonikasyon yöntemi kullanılarak kütlesel olarak 250, 500 ve 1000 ppm miktarlarında karıştırılmıştır. Ayrıca, testler nanopartikül içermeyen geleneksel dizel yakıt (D100) ile de gerçekleştirilmiş ve referans veriler elde edilmiştir. Testler tek silindirli, hava soğutmalı bir dizel motorda, 2400 rpm sabit motor devrinde ve 3, 6, 9, 12 Nm değişken motor yüklerinde gerçekleştirilmiştir. Nanopartikül kullanımın dizel yakıtın ısıl değerini, setan sayısını ve viskozitesini artırdığı gözlemlenmiştir. Test motoru nanopartikül takviye edilmiş test yakıtları ile çalıştırıldığında, motorun yanma, performans ve emisyon karakteristiklerinde önemli oranlarda iyileşmeler saptanmıştır. Nanopartikül takviyesi ile, tutuşma gecikmesi sürelerinin %4,20 ile %13,75 aralığında kısaldığı görülmüştür. Ayrıca, nanopartiküllerin katalizör görevi üstlenip yanma süreci boyunca kimyasal reaksiyonları hızlandırması sayesinde ortalama yanma sürelerinde %6,93'ten %11,73'e kadar kısalmalar saptanmıştır. Tüm test yakıtları arasında, en kısa yanma süresi CuO-Al2O3 hibrit nanopartikül kullanılan yakıtta elde edilmiştir. Öte yandan, frenleme özgül yakıt tüketimi (ÖYT) ve ısıl verim (IV), tüm nanopartikül içerikli test yakıtlarında gelişme göstermiştir. ÖYT değerinde en büyük düşüş, yanma süresinin de en kısa sürdüğü CuO-Al2O3 hibrit test yakıtı ile %11,08 oranında gözlemlenirken, aynı test yakıtı için ısıl verim de %6,57 oranında artmıştır. Yanma sürelerinin kısalması, üstün ısı iletim kabiliyetleri, geniş yüzey/hacim oranı ve gelişen motor performansı, nanopartikül içerikli test yakıtlarında daha düşük egzoz gazı sıcaklığı ve daha düşük NOx emisyonlarını tetiklemiştir. Nanopartikül ilavesi ile birlikte NOx emisyonları için hesaplanan düşüş oranı %8,5 ile %25,8 aralığında değişmektedir. Ayrıca, CO ve HC gibi eksik yanma ürünlerinde de tüm nanopartikül içerikli test yakıtlarında önemli seviyelerde düşüşler gözlemlenmiştir. CO emisyonundaki ortalama düşüş %18,7 ile %34,4 aralığında iken bu oran HC emisyonları için %4,2 ile 20,3 aralığında kalmıştır. Tüm sonuçlar bir arada düşünüldüğünde ise, geleneksel dizel yakıt ile birlikte nanopartiküllerin kullanımı hem enerji verimliliği hem de çevresel hususlar açısından oldukça umut verici sonuçlar sunmaktadır. Ayrıca, hibrit nanopartikül kullanımı ile birlikte motor karakteristikleri üzerindeki iyileşmelerin mono nanopartikül kullanımına göre genelde daha iyi sonuçlar verdiği de gözlemlenmiştir.In this thesis study, it is aimed to investigate the effects of using mono and hybrid nanoparticles on the combustion, performance and emission characteristics of a diesel engine. In this framework, three different types of nanoparticles (Al2O3, bN, and CuO) and their binary hybrid forms (CuO-Al2O3, bN-CuO, and bN-Al2O3) were doped into conventional diesel fuel (D100) at mass fractions of 250, 500, and 1000 ppm by using the ultrasonication method. In addition, the tests were carried out with conventional diesel fuel (D100) without nanoparticles and reference data were gathered. Tests were performed on a single-cylinder, air-cooled diesel engine, at a constant engine speed of 2400 rpm and varying engine loads of 3, 6, 9, 12 Nm. It is observed that nanoparticles increase the heating value, cetane number, and viscosity of diesel fuel. When the test engine was run with nanoparticles-doped test fuels, significant improvements were noticed in the engine's combustion, performance and emission characteristics. With the addition of nanoparticles, ignition delay duration shortened between 4.20% and 13.75%. Moreover, due to the fact that nanoparticles act as catalysts and accelerate chemical reactions during the combustion process, the average combustion duration (CD) shortened from 6.93% to 11.73%. Among all fuels, the shortest CD occurred for CuO-Al2O3 hybrid test fuel. On the other hand, the brake-specific fuel consumption (BSFC) and brake thermal efficiency (BTE) improved for all nanoparticle-containing test fuels. The largest reduction for the BSFC value was observed with the CuO-Al2O3 hybrid test fuel, where the CD was the shortest, at a rate of 11.08%, while the thermal efficiency for the same test fuel improved by 6.57%. The shortened CD, superior heat transfer mechanism, large surface/volume ratio, and improved engine performance ensured lower exhaust gas temperature as well as lower NOx emissions for nanoparticle-containing test fuels. With the addition of nanoparticles, the reduction rate for NOx emissions varied between 8.5% and 25.8%. Besides, incomplete combustion products such as CO and HC emissions were noticed to significantly drop for all nanoparticle-containing test fuels. While the average reduction for CO emissions was between 18.7% and 34.4%, this rate remained between 4.2% and 20.3% for HC emissions. Considering all results together, the use of nanoparticles along with conventional diesel fuel offers very promising results in terms of both energy efficiency and environmental aspects. In addition, it is noticed that the improvements in engine characteristics with the use of hybrid nanoparticles generally give better results than the use of mono nanoparticles
Investigation of performance and emission characteristics of an CI engine fuelled with diesel – waste tire oil – butanol blends
Combustion and vibration characteristics of variable compression ratio direct injection diesel engine fuelled with diesel‐biodiesel and alcohol blends
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