Passenger Aircraft Research Articles

An Event-Driven Link-Level Simulator for the Validation of AFDX and Ethernet Avionics Networks

Aircraft are composed of many electronic systems: sensors, displays, navigation equipment, and communication elements. These elements require a reliable interconnection, which is a major challenge for communication networks since high reliability and predictability requirements must be verified for safe operation. In addition, their verification via hardware deployments is limited because these are costly and it is difficult to try different architectures and configurations, thus delaying design and development in this area. Therefore, verification at early stages in the design process is of great importance and must be supported with simulation. In this context, this work presents an event-driven link-level framework and simulator for the validation of avionics networks. The tool presented supports communication protocols commonly used in avionics, such as Avionics Full-Duplex Switched Ethernet (AFDX), as well as Ethernet, which is used with static routing. Also, the simulator provides accurate results by employing realistic models for various devices. The proposed platform was evaluated in the Clean Sky’s Disruptive Cockpit for Large Passenger Aircraft architecture scenario, showing the capabilities of the simulator. Verification speed is a key factor in its application, so the computational cost was analyzed, proving that the execution time is linearly dependent on the number of messages sent and that the increase in the number of nodes has few quadratic components.

Supersonic passenger aircraft, the Oedipus Trap and the reluctance to reverse a decision.

Supersonic passenger aircraft, the Oedipus Trap and the reluctance to reverse a decision.

Optimum design of additively manufactured aerospace components with different lattice structures

Abstract Nowadays, the need for new technologies is increasing, especially to find solutions to the inadequacies in the production of complex structures. The additive manufacturing methods developed facilitate the production of complex parts and move the technology forward with factors such as cost and efficiency. With the optimization of new parts designed by additive manufacturing methods, it is possible to obtain the optimum product even in the most complex structures. At the end of the production process, the final product with the desired properties is obtained as a result of part size tolerance precision and optimizations. In this study, lattice optimization is applied to a passenger aircraft bracket. It is aimed to reduce the weight and, at the same time, increase the efficiency of the part by optimizing it with lattice structures. For this purpose, the Altair Inspire program was used, and the variation of mass, displacement, safety coefficient, and stress values of the part according to different lattice structures were investigated.

Optimization of landing gear under consideration of vibration comfort for civil aircraft

Purpose This study aims to investigate the design and optimization of landing gear buffers to improve the landing-phase comfort of civil aircraft. Design/methodology/approach The vibration comfort during the landing and taxiing phases is calculated and evaluated based on the flight-testing data for a type of civil aircraft. The calculation and evaluation are under the guidance of the vibration comfort standard of GB/T13441.1-2007 and related files. The authors establish here a rigid-flexible coupled multibody dynamics finite element model of one full-size aircraft. Furthermore, the authors also implement a dynamic simulation for the landing and taxiing processes. Also, an analysis of how the main parameters of the buffers affect the vibration comfort is presented. Finally, the optimization of the single-chamber and double-chamber buffers in the landing gear is performed considering vibration comfort. Findings The double-chamber buffer with optimized parameters in landing gear can improve the vibration comfort of the aircraft during the landing and taxiing phases. Moreover, the comfort index can be increased by 25.6% more than that of a single-chamber type. Originality/value To the best of the authors’ knowledge, this study first investigates the evaluation methods and evaluation indexes on the aircraft vibration comfort, then further conducts the optimization of the parameters of landing gear buffer with different structures, so as to improve the comfort of aircraft passengers during landing process. Most of the current studies on aircraft landing gear have focused on the strength and safety of the landing gear, with very limited research on cabin vibration comfort during landing and subsequent taxiing because of the coupling of runway surface unevenness and airframe vibration.

Optimization of the Aerodynamic Configuration of the Isolated Wing for the Second-Generation Supersonic Passenger Aircraft

Optimization of the Aerodynamic Configuration of the Isolated Wing for the Second-Generation Supersonic Passenger Aircraft

An event-driven link-level simulator for validation of AFDX and Ethernet avionics networks

Aircraft are composed of many electronic systems: sensors, displays, navigation equipment and communication elements. These elements require a reliable interconnection, which is a major challenge for communication networks as high reliability and predictability requirements must be verified for safe operation. In addition, their verification via hardware deployments is limited because these are costly and make difficult to try different architectures and configurations, thus delaying the design and development in this area. Therefore, verification at early stages of the design process is of great importance that has to be supported via simulation. In this context, the present work presents an event-driven link level framework and simulator for the validation of avionics networks. The presented tool supports communication protocols such as Avionics Full-Duplex Switched Ethernet (AFDX), which is a common protocol in avionics, as well as Ethernet, which is used with static routing in such scenarios. The simulator also uses realistic element models to provide accurate results. The proposed platform is evaluated in Clean Sky’s Disruptive Cockpit for Large Passenger Aircraft architecture scenario. The speed of the verification is a key factor, so the computational cost is analyzed, proving that the execution time is linearly dependent on the number of messages sent.

Adaptive zone based active noise control for a moving target

This study focuses on enhancing active noise control (ANC) in room enclosures, specifically targeting zones of quiet (ZoQ) around aircraft passenger seats. By integrating virtual sensing and motion tracking techniques, we aim to dynamically adapt the ZoQ to moving targets. Key to our approach is the strategic placement of actuators and sensors, forming the core of the ANC system. Our methodology includes virtual sensing for ANC analysis, ZoQ optimization for varied applications, and in-depth case studies. We introduce an innovative combination of a speaker gimbal system, a vision system, and custom software for precise motion tracking, significantly improving ZoQ localization. The findings offer insights into maintaining effective ZoQs for multiple input multiple output (MIMO) local ANC configurations, laying the groundwork for adaptive ZoQ control about sound sources and desired cancellation locations. This research marks a significant step towards more effective and adaptable noise cancellation in enclosed spaces.

Converting passenger aircraft into cargo planes under volatile market demand

The COVID-19 pandemic has severely affected airlines’ passenger businesses, while the air cargo sector has been more resilient. To reduce the financial pressure and tap into the profitable cargo business, airlines around the world are actively converting passenger aircraft into cargo planes (i.e., preighters). This paper develops an integrated economic model to examine airlines’ aircraft conversion strategies when facing dynamic market demand due to the pandemic. We consider the possibility of temporary conversion, i.e., passenger aircraft that have been converted into preighters during the pandemic can be converted back into passenger aircraft after the pandemic. We find that when the air cargo transport price is exogenous, the socially optimal conversion rates are lower than the profit-maximizing level for airlines in both the pandemic and the post-pandemic periods, and a government subsidy reduces social welfare. Competition in the passenger market or the cargo market increases conversion rates under both the airline optimum and social optimum, and widens the gap between them. However, if the airlines can influence the air cargo transport price, conversion rates may be higher under the social optimum than under the airline optimum. Competition in the passenger market and the cargo market has opposite effects on the two optimal conversion rates. When the expected cargo market size is small (large), the conversion rates in the social optimum are lower (higher) than the airline optimums, and a government subsidy worsens (enhances) social welfare. Finally, we extend our model by incorporating more real-world factors, such as the lower efficiency of preighters than that of freighters, the freighter leasing market and airlines’ lay-up of idle passenger aircraft. Most of our analytical results remain valid.

Determination of the features of integrated design of civil long-range aircraft with transonic truss-braced wing at the preliminary design stage

The object of research is a civil mainline aircraft with a transonic truss-braced wing. The problem of designing an aircraft of this scheme at the preliminary design stage is being solved in the work. The results of the work include the concept of designing aircraft with a transonic truss-braced wing, the main advantages of such a scheme, the process of determining the geometric parameters of the truss-braced, features of the preliminary design of an aircraft with an extremely high aspect ratio truss-braced wing, possible approaches to the arrangement of units and their mutual arrangement. The results are explained by the difference in the design model (the cantilever beam is replaced by a beam on two supports) in mass analysis and the increased wing aspect ratio in aerodynamic calculation. The final data are based on a statistical study to determine the basic geometric parameters of assemblies of modern mainline passenger aircraft, synthesis of parameters of analog aircraft. For example, an aircraft capable of carrying 250 passengers over a distance of 13.000 km is considered. In the design process, values of aspect ratio, taper ratio, wing area, vertical tail and horizontal tail area ratio, and fuselage dimensions are accepted. Drawings of the general appearance of the aircraft have been developed and, based on it, a master geometry of the theoretical contour has been constructed. Graphs of first-order polar and maximum lift-to-drag ratio have been plotted, the reduction of aerodynamic drag in percentage terms has been determined, and the increase in aerodynamic lift-to-drag ratio in percentage terms for an aircraft with an extremely high aspect ratio truss-braced wing compared to similar characteristics of an aircraft with a conventional non-braced wing has been calculated. The approximate mass savings when using a truss-braced wing on the aircraft are determined in percentage terms. The expediency of using wings of greater aspect ratio, than modern aircraft currently have, has been justified. The expediency of using a brace for the aircraft with an extremely high aspect ratio wing has been justified. The obtained results can be used in practice in the process of developing the preliminary design of an aircraft with a truss-braced wing or in the modifications of existing aircraft to increase their fuel efficiency or increase the durability of wing elements due to reduced loads acting on them.

Dynamic thermal model of passenger aircraft for the estimation of the cabin cooling and heating requirements

The Environmental Control System (ECS) of passenger aircraft is the main consumer of non-propulsive power aboard. A computationally efficient and accurate thermal model of the fuselage is needed for future sustainable aircraft to address ECS preliminary sizing and control design, as the ECS should be re-designed to exploit possible synergies with other thermal management systems on board. Differently from previous works, the present aircraft thermal model is extensively documented and released open-source. Moreover, it is completely based on first principles and the acausal modeling paradigm. It results that the model is scalable, easily extendable, and allows for the estimation of the aircraft thermal loads given limited information about its configuration and flight mission. The predictive capabilities of the model have been assessed by comparing the thermodynamic state estimated at the pack discharge for three ECS operating points of an Airbus A320 with data provided by the manufacturer. The maximum deviation is limited to 2.4 K and 4.5 kPa. The validated thermal model has been used to compute the operating envelope of the A320 ECS, showing that the air supply requirements vary substantially with ambient conditions and flight phases. This calls for a multi-point design strategy when assessing novel ECS configurations.

The Relationship Between Aspect Ratio and Lift/Drag Ratio

Modern aircraft requires a reliable structural design, and the Lift/Drag ratio possesses irreplaceable features in such a design. Most of the current experiments are based on passenger aircraft models and few are conducted on the Lift/Drag ratio of gliders. The value of the Lift/Drag ratio is related to several factors. This paper discusses the relationship between aspect ratio and Lift/Drag ratio. At first, brief corresponding knowledge is provided while predicting such a relationship based on related theorems. Then, an experiment based on self-constructed aircraft is conducted to obtain practical data. Finding that as the wingspan ratio increases, so does the lift-drag ratio. The disadvantage is that the environment is subject to more unstable factors. The experiment can be more accurate if it changes the field without wind. This experiment can provide more realistic experimental data in the field of gliders. The innovative idea of this experiment can be extended to many experiments. Finally, the data are analyzed to form the result. By comparing the result and prediction, the deficiencies in this experiment are discovered in the experiment and improvements are provided. In the end, the whole process and prediction of the future development of related technologies were concluded. By exploring the Lift/Drag ratio of the glider model, the data of the Lift/Drag ratio of the glider can be perfected. The innovation of this experiment can also be applied to research in different fields.

Numerical Simulation of Heat Pipe Thermal Performance for Aerospace Cooling System Applications

The design of integrated and highly efficient solutions for thermal management is a key capability for different aerospace products, ranging from civil aircraft using hydrogen on board to miniaturized satellites. In particular, this paper discloses a novel numerical tool for the design and thermal performance assessment of heat pipes. To achieve this goal, a numerical Ansys Parametric Design Language code is set up to verify the effective subtractive heat flux guaranteed by the selected heat pipe arrangement. The methodology and related tool show their ability to provide good thermal performance estimates for different heat pipe designs and operating conditions. Specifically, the paper reports two very different test cases: (1) solid metal heat pipes to cool down the crotch leading-edge area of the air intake of a Mach 8 civil passenger aircraft, and (2) a copper-water heat pipe to cool down a Printed Circuit Board of a generic small LEO satellite. The successful application of the methodology and numerical code confirms the achievement of the ambitious goal of developing in-house tools to support heat pipe thermal performance prediction for the entire aerospace domain.

УДОСКОНАЛЕННЯ ІСНУЮЧИХ МЕТОДІВ ОЦІНЮВАННЯ ФУНКЦІОНУВАННЯ АЕРОПОРТІВ ПРИ МІЖНАРОДНІЙ ІНТЕГРАЦІЇ

The article is devoted to the study of methods for assessing the operation of airports under international integration and their improvement. The recent scientific studies on assessing the operation of international airports were analyzed and it was found that the most actively used methods are the initial data envelopment analysis (DEA) and various variants of quantile regression, Tobit regression, assurance region methods, SBI and DMU, Malmquist index, classification and regression tree, bootstrapping tool and other tools. It was confirmed that the existing methods for assessing the airports’ operation have a significant number of indicators for calculations based on the evaluation of economic, technical or overall efficiency. The parametric methods for assessing the operation of airports, their advantages and disadvantages were characterized. The methodology of stochastic frontier analysis (SFA), the use of a non-parametric approach to evaluate airport performance, and the evaluation of the overall efficiency of two-stage DMUs with shared resources were described. The methodical approaches based on the use of the spatial regression model, the AAG model and the stochastic frontier model were characterized. The methodology for determining the target function Effi to assess the efficiency of each airport DMUi was described. The scheme for assessing the airports’ operation by input and output indicators was proposed, which includes a three-module assessment system for the passenger, cargo and joint modules. The cargo module is the authors’ own development and its creation is justified by the fact that a significant number of air cargo flows are served by passenger aircraft. The group of input indicators of the cargo module includes the length of the loading and unloading work front, the number of cargo receiving points, the working area of rack and stack storage, the number of electric forklifts and lift trucks, as well as the number of cargo warehouses, and the number of general and special categories of cargo are defined as output indicators.

Авіаційна та космічна галузі в постіндустріальному розвитку

The article raises the issue of the relevance of the development of international cooperation in the aerospace industry, taking into account the trends of post-industrial society, the development of artificial intelligence, and the transformation of the world society. It is specified that one of the key indicators of the transition from an industrial to a post-industrial society is the active development of the service sector and the importance of education and the knowledge economy, which come to the fore. The economy of post-industrial societies is dominated by innovative sectors such as high-performance industries, high-quality and innovative services as a share of GDP, and a larger share of the population employed in the service sector than in industrial production. A country with a highly developed aerospace industry demonstrates its national strength, scientific and technological innovation, effective public policy, strategic vision and principles of national security. At the international level, the leading countries of the world have identified the coordination of space activities and the development of aerospace industry as a priority of the national level. Ukraine has a complete space complex (rockets, spacecraft, ground control centers, data processing centers) and most aviation platforms (reusable spacecraft, some passenger aircraft, military transport, transport-only), has the potential for construction, research and development, can organize the production, operation and use of the rocket, space and aviation technology. The aviation industry and the space industry outline the long-term prospects for the development of the country’s economy. In terms of development, the aerospace industry is ahead of other industries and plays a vital role in modern civilization. The development of the aviation industry is urgent for Ukraine, including the development of ground airport infrastructure, air transport and a combination of ground and air transport.

A synergetic approach to the development of the economic potential of the aviation complex enterprises

The potential of aviation enterprises makes it possible to increase the volume of development and production of aviation equipment, in particular: regional passenger and transport aircraft; aircraft engines and units; on-board radio-electronic equipment aimed at the use of satellite communication, navigation and observation systems; helicopters and general aviation aircraft, including unmanned ones; military goods and dual-use products. It is substantiated that the harmonization of the modern system of state regulation of the integration of the foreign trade sector of Ukraine into the EU should be carried out based on the fact that the parties have excellent reasons for forming an integration association. The consistent implementation of worldview and methodological procedures for maximizing the use of potential is, first of all, a tool for overcoming the low level of economic development, efforts through unification to create better conditions for the industrialization and development of aviation enterprises, the possibility of qualitative transformation of the foreign trade sector by attracting foreign investments and high technologies. This approach should contribute to the fundamental restructuring and diversification of export supplies, increase the opportunities to use positive development trends, and increase the level of international competitiveness of domestic economic entities. The results of the diagnostics of aviation enterprises made it possible to reveal the expediency of forming a new structure of interaction of enterprises and systematizing them into an aviation complex, which is considered as a set of organizations involved in the development, testing, production, sale, operation, modernization and repair of aviation equipment, which form several interconnected clusters.

Overview and Perspectives of Air Mobility Operations and Simulation Tools

The rise of low-altitude passenger and delivery aircraft in urban areas will revolutionize urban mobility, requiring air mobility (AM) systems. This paper provides an overview of AM operations and simulation tools to facilitate research and development. It proposes a software structure for a simulation tool that can model and replicate the behavior of AM systems. By setting the foundation for AM tools and exploring varied concepts, this paper aims to inspire breakthrough research in this cutting-edge domain.

Analysis of noise sources in the cabin of a passenger aircraft and methods for combating them

This paper examined the problem of noise in the aircraft cabin and ways to solve it. Through observations, the following causes of noise were identified: the power plant (acoustic and mechanical vibrations, turbulent boundary layer and others), the location of the engine relative to the airframe, the noise of the propeller (if it is a propeller power plant), the propeller of the power plant itself, the air conditioning system, and so on the same operating device in the cabin. There is a comprehensive way to solve the problem of noise in the aircraft cabin: for aircraft with turbojet engines, measures aimed at changing the design and use of sound- absorbing materials can be effective. For a turboprop aircraft, it is necessary to create low-noise propellers and synchronize the rotation of the propellers. For air conditioning elements, reducing duct and exhaust velocities allows for satisfactory acoustic performance of these sources. The reduction in “cabin noise” is achieved by changing the manufacturing technology of various noisy units. It should be emphasized that the possibility of reduction in the cabin and the aircraft is, in principle, laid down when designing the units and the aircraft as a whole. It is worth noting sound insulation, vibration insulation, as well as the rational location of noisy units, including the power plant, relative to the passenger cabin of the aircraft. From the study on sound insulation, we conclude that it is best to use 2 sound insulation options. Reducing noise is a feasible task and its greatest progress is achieved even at the design stage itself

Methodology for assessing the effectiveness of design and technological solutions in ensuring the service life of power connections of structures

Abstract: A methodology for designing the load-bearing capacity of power parts of machines and structures operating under variable loading conditions is presented, which allows assessing the effectiveness of design and technological solutions based on the criteria of fatigue strength, durability and guaranteed service life. The technique is based on the force calculation of parts and assemblies, the formation of an equivalent block of variable loading, the calculation of the endurance limit in a statistical aspect and the determination of the fatigue life at a given level of reliability. The presented methodology is based on a specific example of calculating and assessing the durability of the elements of the fork connector of the fin and fuselage of a passenger aircraft.

Knowledge collection in aircraft passenger seat assembly: insight for a conceptual design method development

In the field of aircraft system engineering, this research work aims to bridge the gap between conceptual design and quantitative analysis, with a specific focus on the installation of aircraft passenger seats. To achieve this objective, a comprehensive analysis of seat installation process for commercial aircraft was carried out to identify and describe criticalities associated with this manufacturing phase. Different means were used to gather information, starting from the analysis of technical documents, and conducting interviews with industry experts. The research methodology employs a unique translation mechanism, harnessing the power of scoring matrices which are based on a graduated scale ranging from 1 (best option) to 5 (worst option). The scoring matrix serves as a tool for quantifying and translating the qualitative data gathered from the experts into quantitative analysis reflecting the installation process workload. By quantifying the qualitative information provided by the experts, this approach enables a systematic evaluation of seat installation and aids in decision-making within the aircraft assembly domain. In essence, this research contributes a structured and rigorous framework for assessing the ease of installing aircraft components, with a specific emphasis on seats, resulting in an improved assembly process of aircraft.

BOEING 787 Model Daha Elektrikli Uçak Sistem Yenilikleri ve Araştırılan Sorunları

In recent years, MEA technology has brought about developments in the field of power electronics, fault-tolerant architecture, electro-hydrostatic actuators, flight control systems, high-density electric motors, power generation and conversion systems. Non-propulsive systems in traditional aircraft systems, ıt is powered by a combination of different secondary power sources such as hydraulic, pneumatic, mechanical and electrical while the more electric aircraft (MEA) concept ensures the use of optimum electrical power for all non-propellant systems. 
 The goal of future aircraft technology is to replace the majority of non-electrical power-using systems, such as environmental control and engine starting, with electrical systems to improve various aircraft characteristics such as efficiency, emissions, reliability and maintenance costs. B787 series aircraft, the first civil aircraft with more electric aircraft features of modern times, ıt features composite fuselage and wing profiles, fly-by-wire flight controls, advanced cockpit and General Electric or Rolls-Royce engines. Different from previous designs, Boeing has minimized the use of air from the engines in the B787 technology and makes extensive use of electrically powered systems instead of traditional pneumatically powered systems. B787 new generation passenger aircraft, ıt is anticipated that significant improvements such as aircraft weight, fuel consumption, total life cycle costs, carbon neutrality, ease of maintenance and aircraft reliability will reduce the effects of adverse environmental conditions.
 In this study, the system innovations of the B787 aircraft model, which is a more electric aircraft concept and introduces different testing and working methods throughout the design process, and the problems caused by the new systems were investigated.