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Öğe Challenges, prospects and potential future orientation of hydrogen aviation and the airport hydrogen supply network: A state-of-art review(Elsevier, 2023) Degirmenci, Hursit; Uludag, Alper; Ekici, Selcuk; Karakoc, T. HikmetThe use of fossil fuels, which are employed to supply the energy needs of aircraft, is currently causing severe environmental concerns, placing pressure on the aviation industry and mandating specific action. Sustainable aviation fuels that would lessen the aviation industry’s environmental effects are viewed as a potential substitute for fossil fuels. Hydrogen, a clean energy carrier, is regarded as the most promising of these fuels. This paper provides a historical overview of hydrogen-powered aviation, as well as an analysis of the hydrogen supply network, which is regarded as a critical component. As part of the Sustainable Development Goals (SDGs), this study offers a future-oriented concept as well as challenges, prospects, potential future orientation and modifications that can be made to the hydrogen supply network for full decarbonization.Öğe Conceptual design and optimization of a sustainable and environmentally friendly archetypal helicopter within the selection criteria and limitations(Elsevier, 2023) Gunaltili, Enes; Ekici, Selcuk; Kalkan, Abdullah; Gocmen, Faruk Esat; Kale, Utku; Yilmazoglu, Zeki; Karakoc, T. HikmetThe design and mission requirements of aero vehicles, which vary on a day-to-day basis, have become major study concerns in the burgeoning aviation sector. In addition to the design and mission criteria that must be met in an aero vehicle design, the designers’ primary goals are to construct original, innovative, environmentally friendly, fuel-efficient, and sustainable designs. In this study, a detailed conceptual design of a helicopter that does not need a notable runway for operation and is limited by mission and design requirements is offered. Within the scope of this research, a competitor analysis study was undertaken in accordance with the defined criteria, and design approaches were chosen based on the outcomes of competitor analysis. In addition, this research, which looks for an environmentally friendly and sustainable design, was developed with the aviation industry’s demands in mind by analyzing the International Helicopter Safety Team’s (IHST) data. As a result of the reports analyzed and considering the causes and consequences of accidents that have happened, the objective of the design research was to achieve a sustainable, ecologically friendly, and fuel-efficient design by reducing the number of accidents and damage. The planning and design processes as a result of this examination are essential as a step towards the helicopter being an original design and in the context of solution methodologies. This archetypal design aims to shed light on helicopter design studies and serve as a roadmap for future research.Öğe Deep learning-based forecasting modeling of micro gas turbine performance projection: An experimental approach(Elsevier, 2023) Kilic, Ugur; Villareal-Valderrama, Francisco; Ayar, Murat; Ekici, Selcuk; Brooks, Luis Amezquita; Karakoc, T. HikmetPerformance forecasting of aeroengines is crucial for achieving better operational efficiency, ensuring safety, reducing costs, and minimizing environmental impact in the aviation industry. It enables engineers and researchers to make informed decisions, leading to advancements in technology and the overall evolution of aviation. This study is focused on the effects of flight conditions on the performance of a turbojet, which in consequence affects the environmental aspect of operation. By investigating the relationships between aeroengine efficiency and performance indicators such as thrust, shaft speed, and exhaust gas temperature (EGT), and flight characteristics expressed in terms of environmental and operational conditions, the study seeks to elucidate these connections. The article's significance lies in its successful application of Long Short-Term Memory (LSTM) networks to predict thrust, shaft speed, and EGT variations in turbojet engines under varying flight conditions. Experimental data from a turbojet test bench is processed with deep learning, specifically LSTM recurrent neural networks that are developed based on Matrix Laboratory (MATLAB). The model inputs are free stream air speed, compressor inlet pressure, combustor inlet temperature, combustor inlet pressure, turbine inlet temperature, turbine inlet pressure, nozzle inlet pressure and fuel flow, and the outputs are thrust, shaft speed and EGT. Predicted thrust closely aligns with actual thrust values, though with minor discrepancies. Shaft speed predictions exhibit a similar trend, while EGT predictions showcase a comparable pattern with slight variations. Despite the prediction errors, a thorough evaluation of median values, box plots, and probability density functions confirms that the models effectively capture available information, though discrepancies may arise from measurement inaccuracies and initial engine conditions. These results show that it is possible to accurately predict turbojet performance using LSTM recurrent neural network. This research paves the way for enhanced aeroengine performance prediction, particularly in scenarios requiring off-board or high-performance applications.Öğe Editorial: VSI EGET2022(Elsevier, 2023) Karakoc, T. Hikmet; Yu, Zhibin; Ekici, Selcuk; Zhao, JianThe overarching objective of the Glasgow Climate Pact, a bold and ambitious undertaking, is to lay the groundwork for all the world’s economies, without exception, to decisively and irreversibly achieve the remarkable feat of hitting the net zero greenhouse gas emissions mark by the year 2050. The rationale behind this audacious goal is to arrest and neutralize the increasingly dire, ominous and pervasive impact of global warming on a planetary scale, and ensure that the rise in temperatures does not exceed the precarious 1.5? Celsius threshold above pre industrial levels. As such, it becomes crystal clear that it is a matter of utmost urgency that we, as a collective, wholeheartedly embrace and fervently pursue the adoption of green energy technologies, in all their multifarious and sundry forms, to enable us to inexorably advance to wards a state of civilization that leaves no carbon footprint, net or otherwise. However, this formidable challenge can only be surmounted through the vigorous and concerted efforts of the scientific and engi neering communities, who must endeavor to both invent and engineer innovative, cutting-edge low- or zero-carbon energy technologies, while also seeking to optimize and augment the efficiency and efficacy of our current energy systems, all while being mindful of the imperative to optimize cost-effectiveness in the process.Öğe Exergetic, exergoeconomic, exergoenvironmental damage cost and impact analyses of an aircraft turbofan engine(ATFE)(Elsevier, 2022) Balli, Ozgur; Karakoc, T. HikmetThis study presents a detailed exergy, exergoeconomic, environmental damage cost and impact analyses about the aircraft engine turbofan (ATFE) in the aerospace industry. According to the results of investigation, exergy efficiency of ATFE is estimated as 20.32% when the fuel exergy waste ratio is obtained as 79.68%. According to exergy based environmental performance analysis, the ecological effect factor is estimated to be 4.92, while the ecological objective function is found as 38.06 GJ/h. In the exergy based sustainability analysis, the exergetic sustainability index and sustainable efficiency factor of ATFE are obtained to 0.003 and 1.26. These results indicate that waste exergy rate should be reduce to increase exergy efficiency, exergetic sustainability index and sustainable efficiency factor. In the exergoeconomic analysis which is used the specific exergy costing (SPECO) method, the specific cost of fuel and product for ATFE are estimated as 12.56 $/GJ and 85.56 $/GJ while exergoeconomic factor of engine is found as 32.535%. According to Eco-cost and Eco-Indicator 99 methods, the AFTE generates 674.24 $/h-total emission cost rate and 68584.94 mPts/h-environmental impact rate. Besides, the specific environmental impact is determined as 5264.77 mPts/GJ whilst the specific environmental impact cost is obtained to be 0.03 $/mPts.Öğe Exergoenvironmental, environmental impact and damage cost analyses of a micro turbojet engine (m-TJE)(Elsevier Ltd, 2022) Balli, Ozgur; Kale, Utku; Rohács, Dániel; Karakoc, T. HikmetThis study presents a comprehensive investigation of the emission impact, environmental damage cost, exergoenvironmental and life cycle assessment (LCA) analyses of a micro turbojet engine (m-TJE) utilized on Unmanned Air Vehicle (UAV) for four different operating cases. The novelty and motivation to conduct this study are that no study in the literature was done about the environmental damage cost and exergoenvironmental analyses based on exergy and LCA of a micro turbojet engine used on UAVs. According to the results of this study, the engine product exergy rate increasing from 27.119 MJ/h at Case-1 to 114.742 at Case-4 while the engine's specific emission impact (sei) value decreases from 13.346 mPts/MJ at Case-1 to 5.440 mPts/MJ at Case-4. Similarly, the specific environmental damage cost of engine product decreases from 0.150 $/MJ at Case-1 to 0.061 $/MJ at Case-4 whilst the specific exergy cost of engine product goes down from 0.249 $/MJ at Case-1 to 0.088 $/MJ at Case-4. In this regard, the specific exergoenvironmental cost of engine product declines from 0.400 $/MJ at Case-1 to 0.150 $/MJ at Case-4. Besides, the specific exergoenvironmental impact of engine product reduces from 71.694 mPts/MJ at Case-1 to 29.219 mPts/MJ at Case-4 when the relative exergoenvironmental impact difference of engine product falters from 1257.306 % at Case-1 to 453.162 % at Case-4. This investigation shows that an increase in engine product rate reduces specific emission impact, specific environmental damage cost, specific exergy cost, specific exergoenvironmental impact, and relative exergoenvironmental impact difference of engine production.Öğe Fuel-saving and emission accounting: An airliner case study for green engine selection(Elsevier, 2023) Ekici, Selcuk; Ayar, Murat; Karakoc, T. HikmetIn this research, differences in the quantities of hazardous emissions induced by equipping the first composite constructed narrow body aircraft, which is commonly used in commercial aviation today, with the most common engine combinations are examined. Each engine combination that is the subject of this research is actively deployed by a number of airlines and serves the majority of passenger transportation demands. The objective is to clearly depict the variation in the quantities of emissions generated by the various engine types employed in this commonly used passenger aircraft. The instability in the amounts of emissions in various flight phases of the same aircraft, performed with various engine specifications on the same trajectory and route, is determined using EUROCONTROL's Integrated Aircraft Noise and Emissions Modelling Platform (IMPACT), which is founded on the Base of Aircraft Data, Federal Office of Civil Aviation (FOCA), and International Civil Aviation Organization's (ICAO) Helicopter and Aircraft Engine Emission Database. The research seeks to answer the following question: Considering that airlines serve many destinations throughout the year, how much fuel saving and, indirectly, emissions mitigation are achieved per sortie as a result of replacing the engines used by airlines in their existing fleets with the most environmentally friendly equivalents?Öğe Green airport building certification comparison: a practical approach for airport management(Taylor and Francis, 2022) Kacar, Betul; Turhan, Eylem; Dalkiran, Alper; Karakoc, T. HikmetIn this study, six certificates have proposed and three of them used by airport terminal building to analyze, measure, and score environmental damage were compared. Certifications handled in the study are LEED (Leadership in Energy and Environmental Design), BREEAM (Building Research Establishment Environmental Assessment Method), CASBEE (Comprehensive Assessment for Building Environmental Efficiency), SBTool (Sustainable Building Tool), ACA (Airport Carbon Accreditation) and Green Airport and Green Company certificates. As a result, this research gathered the most widely used certificates in the literature. In addition, the Green Airport and Green Company certificate, the first green airport certificate in Turkiye, was added to the study for comparison, which has been offered just for airports. Hong Kong International Airport’s sustainability report was examined to determine how many points it would have received if it had applied for the most widely used LEED, BREEAM, and Green Airport and Green Company Certificates regarding the reported activities. The results have shown that the energy and atmosphere category is vital for all certification systems. Also, the study reveals that LEED gets 89.09 over 100 points, BREEAM 93.1 over 100 points, and Green Airport 75 over 100 points which display BREEAM to get a higher environmental response. This study aims to guide green building practices to decision-makers, which has become necessary in many countries. Employees and managers want to know the quality and quantity of sustainable tasks or planning at airports.Öğe Performance based analysis for the Ankara-London route in terms of emissions and fuel consumption of different combinations of aircraft/engine: An IMPACT application(Elsevier, 2023) Ekici, Selcuk; Ayar, Murat; Kilic, Ugur; Karakoc, T. HikmetThis study analyzes two types of aircraft offered to the industry by two different manufacturers on an identical route and trajectory for commercial aviation and the noxious emissions resulting from equipping these aircraft with the most frequently used engine combinations today. The research covers the most recent Base of Aircraft Data (BADA v4.2_1), the Aircraft Noise and Performance (ANP v2.3), and the ICAO Engine Emission Database (254-ICAO EDDB25/FOCA) based integrated aircraft noise and emissions modelling platform (IMPACT) devel oped by EUROCONTROL. The striking findings in fuel consumption and emissions of four different scenarios during identical flight operations are detailed. The research presents the application of a systematic aircraft engine pair decision mechanism for investigators, scientists, airline operators, policy analysts and legislators, in accordance with a comprehensive computer simulation method that consistently acknowledges the fuel consumption and emissions analysis of aircraft-engine parings.Öğe Promising fuels and green energy technologies for aviation(Taylor and Francis Ltd., 2022) Karakoc, T. Hikmet; Colpan, Can Ozgur; Ekici, Selcuk; Yetik, OzgePromising fuels and green energy technologies for aviationÖğe A review on thematic and chronological framework of impact assessment for green airports(Taylor and Francis, 2022) Dalkıran, Alper; Ayar, Murat; Kale, Utku; Nagy, András; Karakoc, T. HikmetEnvironmental impact assessment comprises a set of analyses, and there are several subjects. However, the “airport impact research” subject has grown into a more integral and broader view. Green airports make this phenomenon more complex when analyzing different operational criteria. This study focused on easing the readers’ understanding of the impact analysis phenomenon more comprehensively. Moreover, the motivation behind this paper is to express the roots of the research subject on the green airport concept. Three domains are defined to classify the impact analysis, affecting each other while focusing on operational or capital investments in the airports. Spending a budget or an organizational function might negatively affect carbon dioxide emissions or further toxic disseminating natural resources. This study has examined 93 published scientific papers to show the distribution of the classified subjects on the three domains as Energy, Natural resources, and economic sustainability. Despite the common superiority of environmental topics, it has been seen that economic efficiency and the importance of the design subjects are the main predecessors in this review. Subjects have diverted into the environmental issues in the later years. Also, popular keywords have been presented to the audience’s attention, which counts the frequency in time.Öğe Unleashing the Potential of Morphing Wings: A Novel Cost Effective Morphing Method for UAV Surfaces, Rear Spar Articulated Wing Camber(MDPI, 2023) Ozbek, Emre; Ekici, Selcuk; Karakoc, T. HikmetThe implementation of morphing wing applications in aircraft design has sparked signifi cant interest as it enables the dimensional properties of the aircraft to be modified during flight. By allowing manipulation of the 2D and 3D parameters on the aircraft’s wings, tail surfaces, or fuselage, a variety of possibilities have arisen. Two primary schools of thought have emerged in the field of morphing wing applications: the mechanisms school and the smart surfaces approach that uses shape-memory materials and smart actuators. Among the research in this field, the Fishbone Active Camber (FishBAC) approach has emerged as a promising avenue for controlling the deflection of the wing’s trailing edge. This study revisits previous research on morphing wings and the FishBAC concept, evaluates the current state of the field, and presents an original design process flow that includes the design of a unique and innovative UAV called the Stingray within the scope of the study. A novel morphing concept developed for the Stingray UAV, Rear Spar Articulated Wing Camber (RSAWC), employs a fishbone-like morphing wing rib design with rear spar articulation in a cost-effective manner. The design process and flight tests of the RSAWC are presented and directly compared with a conventional wing. Results are evaluated based on performance, weight, cost, and complexity. Semi-empirical data from the flight testing of the concept resulted in approximately a 19% flight endurance increment. The study also presents future directions of research on the RSAWC concept to guide the researchers.
