International Journal of Sustainable Aviation (9 papers in press)
Particle filter based integrated navigation for quadrotors
by Ilkay Gumusboga, Emre Kiyak
Abstract: In this work, in order to achieve increased positioning accuracy, a particle filter based integrated navigation system is designed for a rotary wings unmanned aerial vehicle (UAV). As the navigation problem has highly non-linear characteristics on the system and measurement models, the designed algorithm which is based on particle filter works more effectively with respect to Kalman filter-based algorithms which have strict linearity assumptions. In order to verify the proposed algorithm, firstly the designed navigation system is tested with a flight scenario planned in an only simulation environment. After that, the designed algorithm is tested with the data acquired on a real rotary wings system in the laboratory for a different number of particles separately and it has been shown to produce satisfactory results. In this study, an integrated navigation solution having high accuracy and reliability was calculated for a quadrotor having six degrees of freedom.
Keywords: navigation; particle filter; quadrotor; estimation.
Fully Morphing Aircraft Structures: Studies from the Department of Aerospace Engineering, METU, Ankara, Turkey
by Yavuz Yaman
Abstract: This study explains the fully morphing aerospace structures by giving special references to the contributions made by the Department of Aerospace Engineering group of Middle East Technical University, Ankara, Turkey.
Keywords: Fully Morphing Structures; Unmanned Aircraft; Smart Structures.
A Novel Two and Half Dimensional Method for Emissions Prediction of a Reverse Flow Combustor
by GOKHAN VAROL, GURKAN SARIKAYA, Onur Tuncer
Abstract: Development efforts to reduce pollutants such as NOx and CO produced by fossil-fuelled systems such as gas turbine engines have become a necessity. The realization of these efforts in conceptual and detailed design phases before production is very important in terms of reducing the time and costs of the projects. In spite of rapid computer technology development, it is still a difficult and time consuming process to calculate the minor chemical species such as NOx and CO which are released during combustion process. In this study, a methodology is proposed to predict the emissions of a reverse flow combustor of a 1000 horsepower turbo-shaft helicopter engine in the design process. In this methodology, the temperature and mass flow values are obtained by CFD simulations and the CRN model is constructed by using these values. A MATLAB based tool was developed for Chemical Reactor Network (CRN) modelling. And obtained results were compared with empirical correlations.
Keywords: Reverse Flow Combustor; Chemical reactor network (CRN); CFD; NOx; CO; turbo shaft engine emission.
A ROADMAP TO AUTONOMOUS OF AIRLINES ; SPESIFICATIONS AND COMMUNICATION PROTOCOLS
by Hadi Jafarzadeh
Abstract: The future challenge of civil aviation industries will be autonomous air lines that in addition to providing of travel requirements with full safety for passengers and cargo owners, it must has economical savings and benefits for air fleets owners too. The first step in this way is understanding and investigating safe and secure communication methods with proper data transfer speeds that are required for the autonomous airplanes avionics and navigation systems . synchronous, with notice to existing or under developing methods to establish reliable data links for civil aviation, should also look at used technologies in UASs and facilities whom provided for them in accordance with the ICAO and FAA standards. Issues such as redundancy, security and hacking , urban environment health due to the usage of data transmission frequencies and etc, are the major challenges along this path. In this article, after introducing and familiarizing with an autonomous airline and its benefits ,related aircraft and some explanations about communication protocols that can be used for airline autonomy, some of ahead challenges have been addressed and proposed for future work.
Keywords: Autonomous;UAS ;data link ; Frequency; Civil aviation ;UAV; Airline; Communication protocols.
Exergo-economic Analysis of a Hybrid anode and cathode Recycling SOFC/Stirling Engine for Aviation Applications
by Ehsan Gholamian, Pouria Ahmadi, Pedram Hanafizadeh
Abstract: This paper presents an application of solid Oxide fuel cell/Stirling cycle for the aviation applications. Exergy and exero-economic are applied to enhance the understanding of the system performance. Among various kinds of fuel cells, the one with anode and cathode recycling unit is more complex and more effective. Here, a combined cycle based on a methane fueled SOFC and an Stirling engine is proposed and analyzed. EES is used to simulate the system and analyze the results. Results show that with integration of Stirling engine to the SOFC, exergy efficiency increases about 13.66%. Results also demonstrate that air heat Exchanger, SOFC and afterburner have the highest exergy destruction respectively. In addition, exergo-economic results show that the highest and the lowest exergo-economic factors are for the SOFC stack (77.93%) and AHX (2.269%) respectively and thus exergy destruction rate in AHX and investment costs in SOFC should decrease
Keywords: SOFC/Stirling; Anode and cathode recycle; aviation; exergo-economic.
Sustainability reporting in airlines industry: Evidence from Turkey
by Seval Kardes Selimoglu, Arzu Ozsozgun Caliskan
Abstract: Airlines are crucial driver for economic and social development, connecting people, delivering products and transporting goods. Today there is a much clearer recognition of the need to consider aviations contribution to the three pillars of sustainability; economic, social and environment in a more integrated manner. Even sustainability reporting is popular subject in academic literature, sustainability reporting related researches are limited in the airlines. The main aim of this research paper is to address the status of sustainability reports in Turkish aviation industry by focusing airlines. In 2016, there are 13 airlines companies operating in Turkeys civil aviation industry in the field of passenger and cargo carriage. Data of the research collected through web sites visits of the companies, the GRI Disclosure Database, the Public Disclosure Database (KAP) in Turkey. The results show that sustainability reporting practices are not common in Turkeys aviation industry. Among the 13 airlines companies, only one airlines company has sustainability reports. In addition to that, there is one airport operation company and one ground handling company in the sector that publish sustainability reports.
Keywords: Sustainability; sustainability reporting; aviation; airlines; developing country; emerging economy.
Fault Tolerant Control of Attitude Dynamics of Nanosatellites
by Demet Cilden-Guler, Chingiz Hajiyev, Janset Dasdemir
Abstract: In this paper, fault-tolerant active control of the rotational motion of the satellite has been applied. Satellite mathematical models are introduced, and the non-traditional Kalman filter is designed with the presented control algorithms. Re-adjustment control procedure has been established taking into account the identified control distribution matrix. If there are three-axis reaction wheels on the satellite, the failure of one actuator, control setting is carried out using control distribution matrix diagnostics. Extended Kalman Filter has been introduced to control the distribution estimation of matrix elements, so check back adjustment rule is applied by the fault tolerant attitude control.
Keywords: fault tolerant control; attitude; nanosatellite; actuator fault.
Reflection of Sustainability Issues in Airline Strategies and Overview Of Life Cycle Cost Analysis
by Zeliha Akça
Abstract: This study reviews airline fuel efficiency strategies in response to industry sustainability trends based on reports of sector regulators, industry forecasters and airlines. Major strategies in order to achieve fuel efficiency are listed and fuel efficiency gains with new generation aircraft is expressed with historical trends and numbers. The strategy of replacing aging aircraft with younger and/or next generation aircraft provides the largest amount of fuel efficiency. Therefore, this strategy is discussed as a focus of this paper with the underlying motivations. Since aircraft are long-life assets and operating cost of aircraft can change significantly depending on the aircraft type and range of operation, evaluation of aircraft acquisition projects requires meticulous study of costs and benefits over the life span of the project. This study reminds life cycle cost methodology to economically evaluate these projects including complex scenarios. Accordingly, the paper briefly describes general idea behind the methodology and main steps of an application, and reviews literature on life cycle cost analysis indicating that the lack of papers focusing on life cycle cost analysis for replacement projects from the perspective of an airline.
Keywords: Sustainability; fuel efficiency; airline; life cycle cost analysis; replacement analysis.
Consumer Willingness to Pay for New Airports that Use Renewable Resources
by Nathan W. Walters, Stephen Rice, Scott R. Winter, Bradley S. Baugh, Nadine K. Ragbir, Emily C. Anania, John Capps, Mattie N. Milner
Abstract: Over the last few decades, awareness and concern for eco-friendly business practices have continued to grow and encompass industrial fields, such as aviation. The current study determines if people will be willing to pay more for the development of an eco-friendly (green) airport compared to a traditional one, and to see if affect mediates that relationship. The researchers conducted a three-study design using over 1,100 participants. The results indicate that participants were significantly more willing to pay for the airport development if it was perceived as a green airport. Affect was found to have a significant role in mediating the relationship between the type of airport and willingness to pay. Participants felt anger and disgust toward paying for a new airport that did not use renewable resources. Practical applications from the current study and topics for future research are presented.
Keywords: Sustainability; green airports; aviation; eco-friendly; willingness to pay; airport management; emotions; climate change; green marketing; regression.