Sustainable Aviation

Recently, aircraft power systems have started to change enabling more electric aircraft (MEA) concept which aims to replace pneumatic, hydraulic systems with electrical ones as much as possible. Based on this approach, required power generation and distribution amount inside a platform increase, where MW level power generation capacities are seen in current commercial aircraft. As a result of this amount of power, there are some key issues for MEA related with power such as quality, sustainability, and power flow. This paper focused on establishing an analyzing environment for studying these parameters. By using load flow analysis based on Newton–Raphson method, voltage magnitudes and angles at each bus, losses and the power flows at each branch were calculated under a given different sample load conditions on a generic commercial air vehicle. Matlab environment was used to analyze the system in this study. Some of the simulation results have been presented and obtained electrical power system values were evaluated.

Renewable energy sources such as wind energy, solar energy, geothermal energy, and biomass energy are significant energy sources in the world. Some airports, using these sources will be less dependent on fossil fuels and less influenced in environmental pollution. In this study, important renewable energy sources including wind energy, solar energy, geothermal energy, and biomass energy were examined. After that renewable energy sources were investigated for the airport area. Finally, this study showed that the benefits of renewable energy sources for the airports.

Diesel engines are the most commonly used internal combustion engine in transportation, power generation, and other industries. Combustion in the diesel engines takes place at high temperatures due to the high compression ratio, and therefore high energy is obtained when diesel fuel is used. But the most commonly used alternative fuel diesel engines is biodiesel today. The market share of biodiesel is on the rise because of the increasing damage of diesel and decreasing oil reserves to the environment. In this study, cyclic variation that occurred when canola biodiesel (canola methyl ester) that is produced by transesterification method was used as diesel fuel was investigated. Three different biodiesel ratios, B20, B50, and B100 were used in the study. In interpretation cyclic variations wavelet analysis method is used and all results are compared with diesel fuel. It is concluded that the use of biodiesel in diesel engines has positive effect on cyclic variation and this effect increases with the increasing ratio of biodiesel in the mixture.

Integration of sustainable textiles into aircraft design is promoted in order to increase sustainability goals of aviation industry. Textiles used for aircraft interior design not only pose threats to sustainable aims, but also create opportunities. This paper aims to draw the attention to utilize sustainable textiles for ecodesign of aircraft interiors. It also highlights the deficiency and opportunities regarding sustainable textile use for interior parts of the aircraft. The paper states that the environmental impact is created by both aviation and textile industries in a common perspective. The paper also provides examples from sustainable interior design initiatives of automotive industry. The compiled database provides general information about ecodesign approaches and integration of sustainable textiles into aircrafts. Flowingly, a brief summary of the environmental policies are referred.

The rule of thumb for a sustainable air platform is to apply the process of Integrated Logistics Support (ILS) thru Life Cycle of the System. Taking into consideration of all 12 (twelve) ILS Elements especially during the Preparation and Development and In Service phases, then you may have a System that is supportable, sustainable, and affordable.

Previous studies have shown that the level of contact with recycled water has a significant impact on users’ attitude and perceptions toward its use. Recycled water is an engineering process that allows water to be reused for various processes and can mitigate the consumption of freshwater resources used by the airport. The current study aims to determine whether affect mediates the relationship between the type of water recycling projects and a person’s preference toward the use of that airport. Participants were presented with a scenario of an airport that uses recycled water for their sprinkler system or for their drinking fountains. This study found that affect was a significant mediator that mediated the relationship between the type of water recycling project and a person’s preference towards using that airport. We discuss the theoretical and practical implications of this data.

This paper gives an overview of what the airports and terminals at TAV Holding is doing as far as energy efficiency is concerned. The efforts at TAV consist of small incremental projects (addition of insulations, automatic door installation, performance improvements at cooling, heating, etc.) and big projects (Photovoltaic panels, Trigen, etc.). The building structure of the terminals is the main parameter in defining project outlines. Beside terminal structure, there are also other parameters that are affecting the energy performance of the building. By the cooperation with universities, thermal camera analyses had been carried out to detect the thermal insulation efficiency at the terminal shell. Customer satisfaction is the main parameter in terms of passenger comfort in terminal for aviation services. For this purpose, projects were carried out to decrease operational energy consumptions related to HVAC systems and thereby increase in passenger satisfaction. The most energy consuming system in terminals is the HVAC system with the percentage of 60 of the overall energy consumption. Thermal stratification system was implemented in a lounge area in one terminal. All projects had been analyzed for their payback period.

All electric vehicles (AEV) are developed using the new technology; they can be separated in two groups as battery-operated electric vehicles (EV) and fuel cell vehicles (FCV). The subject of this study, fuel cell-battery operated hybrid vehicles, is about full electric hybrid vehicles (FEHV). EV and FCV have different advantages and disadvantages, therefore it is necessary to develop the FEHV vehicles. The fuel cell-battery hybrid systems are under investigation. In the literature, some automotive applications are reported as examples for fuel cell-battery hybrid powered systems. The light hybrid vehicles have been tested in terms of the system design, power management, road tests, and efficiency. All of the presented systems consist of a proton exchange membrane fuel cell system, battery pack, powertrain system, and a connection strategy for powering the traction of an electrical car. However, these are not perfect vehicles, they require further work to address major drawbacks with the connection as well, to increase the efficiency and management of the hybrid components (fuel cell, battery, supercapacitors, motor drive, and electrical systems), motor drive and electrical systems. Their tests and the demonstration results are satisfactory.

The rapid development of the RF power electronics requires the introduction of wide band gap material due to its potential in high output power density. In this project, an X band (8.1 GHz) solid state power amplifier is designed with an output power of 25 W, bandwidth of 150 MHz as a part of an onboard transmitter. We report our result of an AlGaN/GaN HEMT power amplifier with the operating frequency in X band. There has been significant investment in the development of high performance microwave transistors and amplifiers based on GaN in a satellite communication system.

Brayton cycle has a great importance for aviation industry in gas turbines of aircrafts. The aim of this study is to obtain the different efficiency values of one of the combined thermal power plant in our country that its working principle mainly depends on gas turbine Brayton cycle. Ambarlı Combined Cycle Power Plant has been examined to make some comparisons with different efficiency approaches. This power plant is examined by using different efficiency definitions: Thermal, Carnot, Curzon-Ahlborn, Caputo Efficiency and Exergetic Efficiency.

About 75 % of the world’s energy requirement is provided by fossil fuels, and there are various improvement efforts in all fields to ensure the effective use of available sources, taking into consideration the gradual decrease in fossil fuels. Several approaches are used against the decrease in energy sources including the concept of sustainability. Sustainability refers to the careful use of available sources by making advance plans to ensure that natural sources are not exhausted and are used in moderation so that the future generations can benefit from these sources. This study includes a sustainability assessment based on energy analyses for different engine power values varying between 150 and 600 SHP (Shaft Horse Power) in a spark-ignited, unsupercharged and air-cooled piston-prop helicopter engine. As a result of calculations, the highest exergetic sustainability index was found to be 0.15, and the lowest environmental impact factor value was found to be 6.86 at a power of 250 SHP. The lowest waste exergy ratio and the lowest exergy destruction factor were calculated to be 87.28 and 66.77 %, respectively. The power with the highest energy and exergy efficiency provided the highest exergetic sustainability index and thus the lowest waste exergy ratio, the lowest exergy destruction factor and the lowest environmental impact factor.

Cooling systems for HVAC applications in aviation area have a great importance and due to the limited space in complex aviation systems and equipment, energy efficiency is becoming increasingly importance. Energy efficiency affects the design of chillers that account for a significant ratio of the energy consumption in plants. Legal legislations in the short-term limit, and in the long term prohibit the use of refrigerants that have high global warming potential, which are very harmful to the ozone layer. Since air-cooled condensers are among the essential components of cooling groups, efforts to improve their energy efficiency are made incessantly, the related national and international standards are upgraded and limitations on their energy consumptions are always increasing. In light of the latest applicable standards, detailed and comparative information on applications aimed at improving the energy efficiency in air-cooled condensers, highlighting the importance of energy efficiency in cooling installations.

In recent years, reducing the cost of energy production and transmitting electricity in remote areas of the distribution network have attracted many researchers’ attention. One of the methods to fulfill these objectives is using a gas micro-turbine cycle. In this paper, a two-stage micro-turbine with an intercooler was used to produce electricity and heat simultaneously. In this system, the impacts of the effective input parameters, such as compressor pressure ratio, bypass ratio, and re-cooperator yield on cycle performance were studied given that the values obtained from cycle modeling were not continuous, and using GMDH-type neural system (as one of the most widely used neural networks with high potential to model complex data), the desired objective functions were estimated and then simultaneous optimization of the objective functions were implemented. It was shown that the maximum electrical exergy efficiency is 58 % and maximum thermal exergy efficiency is 18 %.

In this work, a unified method is proposed for the buckling analysis of a simple supported column with rotational springs at both ends. The displacement is represented by a Fourier sine series. Stokes’ transformation is applied to boundary conditions in order to construct the coefficient matrix of the corresponding systems of linear equations. The derived linear equations can be useful in theoretical investigation that leads to determinant calculation of a 2 × 2 matrix. The present 2 × 2 matrix is more efficient for calculating the buckling loads of the simple supported columns with rotational springs at both ends.

The purpose of this study is to predict the pollutant emissions generated within a 1000 hp turbo-shaft helicopter engine reverse flow combustor using two different approaches; a flow network-based one-dimensional network solver and a Chemical Reactor Network (CRN) model. The one-dimensional network solver is able to estimate mass flow distributions across holes, gas and liner temperatures, heat transfer and pressure drop across the combustion chamber. All are key parameters for a preliminary design. One-dimensional flow network model is also able to predict the emissions by utilizing a number of empirical and semi-empirical correlations. CRN model is based on the division the combustor flow field into a number of specific zones represented by simple chemical reactors such as Perfectly Stirred Reactors (PSR) and Plug Flow Reactors (PFR). CRN is created to estimate the emissions using CHEMKIN software and the reaction mechanism of n-heptane is provided to be used. CRN model receives mass flow rates from the one-dimensional network model. The results of two approaches are compared for three engine power settings for idle, cruise and take-off.

The design of serviceable stratospheric balloon requires descent control mechanism to make it safe and reliable. On the basis of balloon dynamics, heat and mass transfer aspect, Gas-Compress-Release control model that is developed before used to describe the ascent, descent and flight processes for high altitude zero pressure balloons. The behavior of the balloon system during safe landing has been numerically investigated for the first time. The model was validated using NASANASA test flight. The effect of PIDPID control on compress-release mechanism is discussed in detail. It was found that with the sacrificial flight Gas-Compress-Release model it is possible to place the balloon at its orbit, to extend flight time and to interfere with the balloon system whenever needed for technical service without using ballast. The results are helpful for the design and operation of safe and reliable serviceable high altitude stratospheric balloons.

Significant evolutions of aircraft, airspace and airport systems design and operations are driven by the continuous increase of air transport demand worldwide and by the concurrent push for a more economically viable and environmentally sustainable aviation. In the operational context, novel avionics and air traffic management (ATM) systems are being developed to take full advantage of the available communication, navigation and surveillance (CNS) performance. In order to attain higher operational, economic and environmental efficiencies, the generation of 4-dimensional trajectories (4DT) shall integrate optimisation algorithms addressing multiple objectives and constraints in real-time. Although extensive research has been performed in the past on the optimisation of aircraft flight trajectories and very efficient algorithms were widely adopted for the optimisation of vertical flight profiles, it is only in the last few years that higher levels of integration were proposed for automated 4DT planning and rerouting functionalities. This chapter presents the algorithms conceived for integration in next generation avionics and ATM Decision Support Systems (DSS), to perform the multi-objective optimisation of 4DT intents. In particular, the algorithms are developed for 4DT planning, negotiation, and validation (4-PNV) in online strategic and tactical operational scenarios, and are conceived to assist the human flight crews and ATM operators in planning and reviewing optimal 4DT intents in high air traffic density contexts. The presented implementation of the multi-objective 4DT optimisation problem includes a number of environmental objectives and operational constraints, also accounting for economic and operational performances as well as weather forecast information from external sources. The current algorithm verification activities address the Arrival Manager (AMAN) scenario within a Terminal Manoeuvring Areas (TMA), featuring automated point-merge sequencing and spacing of multiple arrival traffic in quasi real-time.

Silicon-based semiconductor devices are rapidly approaching the theoretical limit of operation, making them unsuitable for future military and industrial applications. In a high electron mobility transistor (HEMT), two-dimensional electron gas (2DEG) which is formed at AlGaN/GaN interface is a critical part to tune the performance of HEMT devices. Inserting high bandgap layers, especially AlN spacer layer between AlGaN and GaN layer improves 2DEG density, mobility, and effects on quantum well. ATLAS toolbox of Silvaco results shows ID-VDS characteristics of the 1 μm gate length. Simulation results show both piezoelectric and spontaneous polarization effects at the interfaces of Al0.30Ga0.70N/AlN/GaN structure, contrary to the conventional HEMTs. The insertion of the very thin AlN interfacial layer (1 nm) supports high mobility at high sheet charge densities by increasing the effectiveness and decreasing alloy scattering. Devices based on this structure exhibit good DC and RF performance.

Optimal linear Kalman filter (OLKF), fault detection, fault isolationFault isolation, Robust Kalman filter (RKF) and reconfigurable Kalman filter algorithms have been applied on the control system of an Airbus-340 aircraft this study. The discrete flight dynamic model of the Airbus A-340 aircraft is presented and discussed. Sensor faults have been implemented in two scenarios: continuous bias fault and noise increment fault. The fault isolation proposed algorithm involves the computation of the statics which is a rate of sample and theoretical variances. The algorithms for fault-tolerant estimation of aircraft states are discussed. Two types of fault accommodation algorithms: RKF and reconfigurable Kalman filter are investigated. Two different approaches of RKF have been tested applied to the Airbus A-340 aircraft model of dynamics: single measurement noise scale factor (SMNSF) and multiple measurement noise scale factor (MMNSF).

In order to calculate the aerodynamic forces of a tilt-rotor, a calculation of the velocity induced was important. For this, the integral method is used for solving the Laplace equation, and discretization is used to find the velocity induced in all point of the blade surface and wake surface.

This chapter presents a contrail mappingContrail mapping algorithm developed for integration into a Multi-objective Trajectory Optimisation (MOTO)Multi-objective Trajectory Optimization (MOTO) software framework, targeting the mitigation of environmental impacts associated with aviation-induced cloudiness. The presented linear contrail mapping algorithm exploits analytical and empirical models to determine the formation, persistence and radiative properties of contrails along a defined flight trajectoryFlight trajectory. In order to determine the contrail formation and persistence, the algorithm takes into account aircraft characteristics as well as relative humidity, temperature, pressure as well as the speed and shear of winds aloft, derived from suitable weather forecast data inputs. The linear contrail mapping algorithm generates an accurate mapping of the contrail persistence and associated Radiative Forcing (RF) along a flight trajectoryTrajectoryFlight trajectory based on inputs of weather data and aircraft state. A 3D contrail mapping algorithm is developed by executing the linear contrail mapping algorithm along an arbitrary number of virtual sounding trajectories. These virtual trajectories are constructed radially around a centre position, at individual flight levels. Multiple 3D mappings are exploited to characterise time variations, ultimately leading to a 4-dimensional (4D) mapping in space and time of contrail formation, persistence and RF properties. These 4D contrail mappings 4D contrail mappingcan be exploited in a MOTO software framework to assess and minimise the environmental impacts associated with contrails.

It is crucial to predict the ice mass, shape and regions of the airframe which are prone to icing in order to design and develop de/anti-icing systems for aircraft and airworthiness certificationAirworthiness certification. In the current study, droplet collection efficiencyDroplet collection efficiency and ice shape predictions are performed using an originally developed computational tool for a wing tip for which experimental and numerical data are available. Ice accretion modeling consists of four steps in the developed computational tool: flow field solution, droplet trajectory and collection efficiency calculations, thermodynamic analyses and ice growth calculations using the Extended Messinger Model. The models used for these steps are implemented in a FORTRAN code, which is used to analyze ice accretion on 2D geometries including airfoils and axisymmetric inlets. The results are compared with numerical and experimental data available in the literature.

VectoringVectoring, automated methods and speed control are available sequencing Sequencing methods defined by International Civil Aviation Organization (ICAO). Point Merge System (PMS) Point Merge System (PMS) is an innovative method for merging and sequencing arrival traffic flows. In this study, proposed PMS model for converging runways Converging will be applied to International Istanbul Ataturk Airport. PMS and vectoring will be compared in real-time simulation and the results are assessed in terms of traffic sequenceTraffic sequence.

This paper presents some novel results found using integrated passive and active morphingIntegrated Passive and Active Morphing during different helicopter maneuvers. A nonlinear, rigid blade helicopter model is linearized around three different maneuvering flight conditions. A specific variance constrained controller namely OVC is applied for flight control system. Parameters of autopilot and morphing parameters are simultaneously determined in order to minimize control energy while there are constraints on helicopter and control design parameters. A stochastic optimization method is used for this purpose. Closed loop system response analyses are done in order to see superiority of integrated passive and active morphing with respect to nominal helicopter and existing two morphing approaches.

Oscillatory events at low frequencies are commonly witnessed in interconnected power systems. Phasor Measurement Units (PMU)Phasor Measurement Units (PMU) can provide time-synchronized measurements; it can communicate the synchronized local and inter-area information to remote station. In this paper, we have modeled a PMU, and we have tested it in the 14-bus power systemPower system. It proposes a real-time monitoring tool that exploits synchronized phasor measurements from PMUs, which allow real-time analysis of higher-frequency events, filling the lack of such monitoring application in the power systems area.

The new technologies and designs on Unmanned Aerial Vehicles (UAVs) Unmanned Aerial Vehicles (UAVs) have created a new market which made it possible for many countries to compete by penetrating and dominating the market. The new advances in computer and material science enhanced data link capabilities; developments in sensor technologies and the component miniaturization are the main factors which strengthen the UAV capabilities and accelerate their usage. The UAV applications which become diversified each passing day, have also been leading up to new projects on commercial air transportation in terms of design and areas of usage. In this framework, UAVs become a valuable instrument for development and testing of new fuel and propulsion systems which are one of the concerns of sustainable aviationAviation. The aim of this study is first to explore the historical development of UAVs in the world, second to investigate the main UAV projects proceeded by Turkey and finally to reveal the future targets and the status of Turkey among the countries securing enhanced UAV experience.

Environmental performance commitments, complex government requirements and market conditions force aviation industry lead aircraft manufacturers to produce lighter and more efficient products. New concepts and designs are not possible to manufacture with traditional manufacturing methods. Additive manufacturing (AM) methods may answer to the needs of industry.

In this study, four different types of aircraft bodyAircraft body were analyzed according to the aerodynamic flight conditions in the form of cruiseCruise. A319, A320, A330, and A340 model aircrafts of the Airbus firm were used. Only the body parts of the plane were drawn and the analysis process has been studied in a scale of 1/1000 for convenience.

This paper presents numerical flow field and heat transfer analysis of a channel consisting of upstream and downstream channels and a 180° bend. Turbulators (rib) with a square cross-section are placed in the straight part of the channels in order to enhance the heat transfer while flow enters to the model at fully developed conditions at Reynolds numbers of 20000. A constant heat flux boundary condition is provided from the bottom wall of the model. Numerical simulations are performed by a commercial solver using realizable k-ε turbulence model with enhanced wall treatment. The flow field development and evaluation of pressure drop accounted by each rib are analyzed along the channel. The effects of ribs to the flow field are characterized by wall shear distribution. The effect of u-bend on the downstream flow field is investigated.

In recent years, flow control methods on an airfoil have gained interest. Flow control methods Flow control methods can be classified as passive and active control systems. Dielectric barrier discharge (DBD) Dielectric barrier discharge (DBD) plasma actuatorPlasma actuator is an active control method. A DBD plasma actuator can be defined as; a flow control device, without moving parts and same airfoil shape after installation. In this study, numerical analysis of DBD plasma actuator integrated airfoil was performed. Instead of modeling plasma generation, thermal effects, ionization, and momentum forces, a momentum source term was applied to the airfoil Airfoil in order to observe the effects of plasma actuator integration on airfoil such as drag, lift, etc. ANSYS Fluent was used in the simulations. The cord length was assumed to be 150 mm. The effects of the attack angles were also investigated with 0°, 5°, 10°, and 15° attack angles. Hexahedral mesh structure Mesh structure was selected in order to model boundary layer with lower y+ values and k-ω SST turbulence model Turbulence model was used. The air velocity was assumed to be 1.9 m/s at the inlet and 200 N/m3 body force was applied to 10 mm after the leading edge for plasma effect analogy.

Within the concept of this study, first low Reynolds number flow phenomenaFlow phenomena, including laminar separation bubble (LSB)Laminar separation bubble (LSB) and stall were explained. Then a literature review on the acoustic flow control was presented in three categories: flow control with constant frequency, flow control with constant amplitude, and flow control with variable frequency and amplitude. Aside from the review part, results of a comprehensive experimental study on the effects of acoustic flow control at low Reynolds numbersLow Reynolds numbers were presented. Within the scope of this experimental study, the effects of both parallel and perpendicular acoustic flow control were examined by means of pressure measurements, force measurements, hot-wire anemometry, flow visualization, and particle image velocimetry (PIV). In order to establish a baseline data, all of the measurements were first applied for the no control case. The effects of acoustic controlAcoustic control were examined especially on the characteristics of LSB and stall. It was found that the acoustic excitation can be employed to decrease the height and length of LSB leading to increased lift coefficient and decreased drag coefficient. Also, acoustic flow control increased the angle of stall. It was also seen that the effective excitation frequency increases also, but the range of Zaman number (St/Re0.5) based on effective frequency still is approximately same with increasing Reynolds numbers. Finally, it was shown that the general aerodynamics performance of an aerofoilAerofoil at low Reynolds numbersLow Reynolds numbers can easily be enhanced by employing acoustic flow control, and the parameters of the acoustic flow control can easily be adjusted in order to keep up with the changing conditions of flow.