New Frontiers in Sustainable Aviation

Today, the use of renewable energy sources is one of great importance. Beside the use of these energy resources, storage is also an important issue. In this case, batteries are vital. In this study, temperature distributions, electrical analyses are conducted. All of these studies take a lot of time, and it is shown that very accurate estimation is made using artificial neural networks. Within the scope of the study, ten lithium-ion prismatic batteries are connected in series. It is determined that this temperature (safe operating temperature must be lower than 313K) value is exceeded at 2.5C. In addition, it is seen in the case of 2C discharge that the air inlet velocity is 0.5 m/s and the temperature is 295K, which is out of the desired range. Therefore, it is recommended to work at lower C rates and either increase the air intake speed or lower the temperature. ANN is a very important tool in predicting data. The best result is found with the Bayesian regularization-18 algorithm, and the coefficient of multiple determinations, the root mean square error and covariation values of the test values for maximum temperature are found to be 0.998985, 0.006460 and 0.007024, respectively.

Aerodynamics of airfoils is always of great interest due to the continuous developments in aviation technology. In addition to the substantial data in the existing literature, important aspects of this flow phenomenon are still being investigated both numerically and experimentally. Particularly, the aerodynamic performance characteristics of various airfoil profiles are examined due to the fact that adverse pressure gradients may occur in the boundary layers over airfoils. These type of boundary layers are usually prone to flow separation, which considerably changes the pressure distribution over the airfoil and thus the lift and drag forces acting on this blade profile. Therefore, this flow mechanism arouses researchers’ curiosity to consider the control techniques of these boundary layers. There are active and passive boundary layer control methods, which can prevent the flow separation and result in drag reduction. This chapter summarizes the details of some of these techniques to help in understanding the insights on the boundary layer flow separation and control for improvement in aerodynamic performance.

Wind distribution is one of the most important parameters in an airport design. As the properties of the wind change, such as speed and direction, flight paths and runways must be changed. In order to prevent a delay on a flight, historical wind characteristics of the runway must be known. Thus, planning of flights can be scheduled in a probabilistic way that the flight safety is increased where delays and costs are decreased.

In this work, real wind speed measurements of a runway are divided as monthly, seasonal and yearly to model the characteristics for short- and long-term effects. Monthly wind speed models are proposed, and their performance is statistically analysed. Then, three-dimensional seasonal wind models with daily and hourly distributions are developed. Lastly, wind rose chart for the Eskisehir Hasan Polatkan runway is obtained and compared with the orientation of the runway.

Flutter can be defined as dynamic instability of an elastic body. The critical flutter can cause poor functionality, such as torsional divergence and control surface reversal. Flutter can be a terrible phenomenon if there is coupling between the bending and torsional motion. Such coupling can be delayed using various suppression techniques.

This chapter reveals the methods to improve the torsional stiffness of the primary control surface, to delay coupling between torsional and bending motion. A simple and effective means of forming a light weight and highly stiffened plate is included in a corrugation design. A corrugated plate provides highly anisotropic behaviour in desired direction. This corrugation design can be installed on control surface to improve torsional stiffness and to shift natural frequency at which flutter occurs to a higher value. Apart from corrugation design, the other methods to prevent flutter are also discussed in this chapter.

This chapter reveals designing of corrugated plates with various corrugation shapes, such as triangular, trapezoidal and semicircle. Two major parameters focused throughout the chapter are modal frequency and stiffness of corrugated plate. Static and dynamic analysis for all corrugations is discussed by obtaining modal frequencies of all corrugated plates. The optimization of corrugated plate, such as shape of corrugation, height-to-width ratio of corrugation, number of corrugated panels to be used and distance between corrugated panels, is discussed in detail. Lastly, comparison between optimized designs is discussed thoroughly.

Environmental control system (ECS) is used in the aircraft industry to define the systems and equipment associated with ventilation, heating, cooling, humidity/contamination control, and pressurization in the occupied compartments, cargo compartments, and electronic equipment bays. ECS controls the air-conditioning system, consists of an air cycle machine (ACM), and several heat exchangers, depending on the design and control valves. The component of an aircraft needs energy, and it is obtained by the aircraft fuel. Since the fuel is the limited and only source of power, consequently, to make flight operation more efficient with lesser cost, it is necessary to examine the efficiencies of components during the changing operating conditions. This chapter presents an overview of the corresponding system, the thermodynamic analysis of the air refrigeration cycle, the exergy analysis of the system for various flight operations, the analysis results by exergetic efficiency, and the exergy destruction on the component level, along with the exergetic improvement potential for every single component. The results showed that preheating heat exchanger and the main heat exchanger have the highest exergy destruction ratio and exergy improvement potential for different flight conditions. Therefore, improvements in heat exchanger design and optimization studies are among the issues that should be focused on to increase ECS performance.

In this study, a life cycle energy assessment was made for energy consumption based on the glazed facades of airport terminal buildings for ten European cities. In the glazed facades, double glazing with an air gap is used. The vertical or different inclined angles of the glazed facade have been investigated. The overall heat transfer coefficient has been calculated based on conduction, convection, and radiation heat transfer case. The heating and cooling degree-day values ​​were calculated by taking the indoor temperature 22 °C for the heating period of the airport buildings and 24 °C for the cooling period. The present worth factor value has been calculated, depending on the interest and inflation rates in the selected European countries. Natural gas was used as an energy source during the heating period and electricity during the cooling period. In the calculations, natural gas and electricity prices in the selected European countries are taken into account. Accordingly, heat energy load, cool energy load, and life cycle energy total cost (LCET) calculations have been made for the long term.

A greener aviation application is needed due to recent increases in air travel and transportation, operating and maintenance costs of aircraft, and limited fossil fuels used in the aircraft which need to be reduced. Environmental concerns caused by climate change and global warming have opened the door to new approaches in aviation, allowing the transition from conventional aircraft to more electrical crafts. Electrical systems have been replaced with the traditional mechanical, hydraulic, and pneumatic energy systems for the demand of lighter and more efficient aircraft design, and thus, major innovations in aircraft power systems, such as power electronics, electrical load management, energy storage, thermal management, power generation, and distribution, have been seen. In this study, advances in aircraft power systems for sustainable and more efficient aviation experience are examined from a technological perspective, considering environmental effects.

Life cycle cost (LCC) is defined as the total cost of a project over its life span that begins at the initialization of the project and ends at the finalization of the project. This chapter describes a methodology based on LCC to economically evaluate replacement strategies for aging aircraft from the perspective of an airline. A case study is conducted to demonstrate how to use the methodology as a decision support tool to economically evaluate and compare aircraft types and assess operation dynamics and replacement strategies. The scenarios are constructed in the case study to define replacement strategies with different types of aircraft and acquisition strategies, including purchasing through financial leasing and short-term and long-term operating leasing. The analysis considers acquisition and sustaining costs, including depreciation and passenger spill costs. In addition, a sensitivity analysis for critical parameters and a strategic comparison based on competitive fitness factors are performed. The results suggest the replacement of old aircraft immediately at the beginning of the horizon and recommend a new-generation aircraft for replacement alternative due to the maintenance and fuel cost advantage. The results also reveal the importance of including age effect on fuel and maintenance, which may change the economic assessment.

In this study, an unmanned aerial vehicle (UAV) similar to the Anka model was designed, and its aerodynamic effects were analyzed experimentally and numerically. Firstly, dynamic similarity studies were conducted in order to get similar results from the experimental environment and computational fluid dynamics (CFD) working environments. Then, drag coefficient values depending on wingspan study were conducted with CFD package program in order to select the appropriate wingspan for the experimental environment. Consequently, numerical aerodynamic coefficient results were in good agreement with experimental aerodynamic coefficient results. At the same time, varying aerodynamic performance analysis and pressure distribution were performed in CFD package program depending on the Reynolds number. Depending on the change of angle of attack, drag coefficient (C_D), lift coefficient (C_L), and aerodynamic efficiency studies have been carried out.

In the postindustrial revolution period, economic policy practices based on growth created an increasing need for energy and raw materials. Due to the limited resources, the growth-focused system has come to the point of collapse. Aviation is one of the biggest industries affecting the environment. Airports benefit from sustainability practices in order to continue their existence in environmental, social, and economic terms. There are many airport sustainability practices in the world. Their success also varies from country to country. When these applications are examined in detail, which ones can be used can be interpreted more easily. In this chapter, the airport sustainability applications are mentioned, and then the studies related to these applications are mentioned. Additionally, the concept of airport sustainability was examined, and the dimensions of sustainability were analyzed.