bluuebunny/crossref_metadata_2025 huggingface dataset:
Cross-border Free Route Airspace concept and its impact on flight efficiency improvement
Authors: Majka Andrzej , Pasich Aleksandra
Published: February 2022

The implementation of Free Route Airspace (FRA) in European Airspace has significantly reduced flight distances. However, there are still elements in the conventional FRA that need to be optimized in order to allow a further improvement in flight efficiency and these are the predefined entry and exit points that are still obligatory to be inserted in a flight plan by the crews and to be flew over during the flight. The introduction of cross-border FRA is another milestone towards the improvement of flight and Air Traffic Management (ATM) systems efficiency. The purpose of the article is to examine the possibility of implementation and expansion of already existing cross-border FRAs and how much distance would be saved if it was possible to fly in a cross-border FRA, instead of a conventional FRA. Thus, two possible scenarios on the extract of a chosen flight route, based on a real-world flight, operated by inter alia LOT Polish Airlines, are examined. Route distance extension was calculated using the Horizontal Flight Efficiency method. Subsequent calculations include potential flight time savings along with fuel waste, CO2 emission and operating costs. The validation of the results obtained through calculation was conducted on X-Plane 11 as a simulation of two examined scenarios, using a Boeing 737-800. The results of the calculations and simulations indicate that the implementation and expansion of cross-border FRA may have a positive impact on flight efficiency improvement due to the reduction of distance and consequently the flight time, fuel waste, CO2 emission and operating costs. It can also mitigate the problem of the European Airspace capacity gradually reaching its maximum level. Thus, there is still a lot of place for further optimization of air traffic flow in European Airspace.
Protecting aviation safety against cybersecurity threats
Authors: Stastny Peter , Stoica Adrian-Mihail
Published: February 2022

In Air Traffic Management (ATM), Safety Management Systems (SMS) form the principal vehicle for implementing safety policies, practices and procedures in accordance with internationally agreed Standards. In a constantly changing operating environment, it is essential to maintain SMS effectiveness to maintain and enhance levels of ATM safety. Research at the University Politehnica of Bucharest (UPB) has analysed the major, fast-rising threats to ATM safety emerging in the cybersecurity field, and the related synergies between formal management systems in the fields of security and safety. Its ultimate objective is to assess the feasibility of equipping SMS with protection against security risks, especially cybersecurity. It further explores the potential effects of cybersecurity threats to aviation safety and the available protection mechanisms. In considering the synergies between Security Management Systems and Safety Management Systems in ATM, the possibility of full integration of the two into a single protection system is explored. Whilst, despite similarities, such a combination is not found to be an optimal arrangement, the examination nevertheless enables the derivation of the security measures required in order to enhance the effectiveness of SMS.
Fully automated piping in an Airbus A320 landing gear bay using graph-based design languages
Authors: Neumaier M , Kranemann S , Kazmeier B , Rudolph S
Published: February 2022

System design in an aircraft is still a costly, manual and iterative approach. One major cost driver of changes in system installation are design efforts for creating new pipes in an earlier stage and the costs accumulated during the in service life. To reduce these costs and the time to market, an automation approach with an integrated design optimization encoded in graph-based design languages and executable in a design compiler is proposed.

To generate the pipe work automatically, a set of input data (e.g. start- and end-points of a pipe with tangents and fixing positions) is given by the user. It also contains, among others, the weightings for the optimization criteria (e.g. length of the pipe resp. the weight vs. the number of bends) to influence the evaluation of the generated pipes and thereby the final solution. As an initial step in the automatic pipe generation process, a route through the installation space is searched. Subsequently, the installation space is simplified and a respective minimal distance to each obstacle which a pipe should satisfy is added. Then for each pipe an initial solution is estimated and each pipe is optimized by a simulated annealing algorithm. At last, all given requirements are automatically verified. The capabilities of the newly developed automated piping are demonstrated on the pipe work in an Airbus A320 landing gear bay.
Creation of innovative concepts in Aerospace based on the Morphological Approach
Authors: Todorov V T , Rakov D , Bardenhagen A
Published: February 2022

The development of innovative aircraft configurations can be an important contribution to achieve the emission reduction goals set for the aviation industry. However, current common aircraft conceptual design processes only allow the consideration of a limited number of initial configurations thus leaving possibly more efficient solutions out of scope. A significantly wider range of aircraft configurations can be taken into account by applying the Morphological Analysis. After a brief presentation of its historical background and actual applications in other domains, this article focuses on the use of this method and its benefits in aerospace. The summary and comparison of several applications in the field of aircraft design show that these still require a higher level of formalisation and robustness. For this purpose, the main steps required to integrate morphological analysis into the aircraft conceptual design phase based on the Advanced Morphological Approach are identified. These are the definition of the morphological matrix along with the evaluation criteria, the obtaining of option evaluations, filtering the impossible solutions and exploration of the solution space.
Development of a combined Artificial Neural Network and Principal Component Analysis technique for Engine Health Monitoring
Authors: Giorgi M G De , Strafella L , Menga N , Ficarella A
Published: February 2022

In aerospace sector, reliability is a crucial point. Modern technologies widely use Artificial Intelligence (AI) algorithms together with detections by sensors in order to design a health-based maintenance plan which stops an aircraft only when needed. In this work, an Engine Health Monitoring (EHM) system was developed by exploiting AI algorithms as Artificial Neural Networks (ANNs) trained to estimate a series of Performance Parameters (PPs) used as index of the health status of the main components constituting an engine. A neural network called Feed-Forward Neural Network (FFNN) in combination with a Principal Component Analysis (PCA) for feature reduction was used in this paper. The software Gas turbine Simulation Program (GSP) was used to generate a series of data containing information about engine performance under different flight conditions and compressor degradation levels. The datasets were subsequently used to train the neural networks to estimate the PPs of the degraded component. The final purpose of the present work is to develop an efficient diagnostic system useful to increase flight safety and decrease maintenance costs and fuel consumption.
Specific Aspects in Numerical Simulation of Complex Processes in Gas Turbine Engine Bearing Chamber
Authors: Mykhailenko T P , Lysytsia A Yu , Petukhov I I , Kovalov A V
Published: February 2022

The complex interrelation of thermal and hydraulic processes in a gas turbine engine bearing chamber requires modelling methods based on the multiphase flow mechanics and Computational Fluid Dynamics (CFD) to predict the fluid distribution and heat transfer phenomena. This paper presents a study of different approaches to CFD modelling of multiphase oil-air flow in the bearing chamber. The Volume of Fluid and Eulerian multiphase models, Steady and Transient solvers, “Realizable k-ε” and “k-ω SST” turbulence models were analysed. The Eulerian Wall Film Model implemented in ANSYS Fluent was applied to model an oil film formation on the bearing chamber walls. The CFD results were compared with available experimental data to formulate practical recommendations for precise modelling of processes in the bearing chamber.
Statistical analysis of sloshing-induced dissipative energy across a range of Froude numbers
Authors: Constantin L , Courcy J J De , Titurus B , Rendall T C S , Cooper J E
Published: February 2022

Fuel sloshing-induced damping is currently being studied extensively within the EU-funded SLOWD project as a means of passively reducing dynamic loads in aircraft wings. It is of interest to be able to determine which parameters have the greatest influence on the added damping from the sloshing motion. An uncertainty in the measured sloshing force has been observed when multiple consecutive and identical oscillation cycles are considered in sinusoidal excitation experiments, leading to variations in the measured energy dissipation. This current work considers liquid undergoing vertical sloshing motions for different fill level and excitation conditions (frequency and amplitude) leading to energy dissipation via several possible physical mechanisms. The sloshing dissipation is measured experimentally across a large number of excitation cycles and for each excitation amplitude, expressed in the form of Froude (Fr) numbers. Depending on the Fr number, distinct sloshing mechanisms dominate the dissipative effects and induce a particular variance across the identical cycles analysed. The sloshing-induced energy dissipation variation is quantified and correlated with different mechanisms depending on Fr number, helping to explain various non-stationary effects that are observed even in well-controlled experimental conditions. As well as improving the insights into the inherent dispersion nature of the studied phenomena, this research also establishes experimental characteristics suitable for future model validation and calibration.
The preliminary design of a scaled Composite UHBR Fan for a wind tunnel test campaign
Authors: Paletta N. , Flüh J. , Lindemann J. , Seume J. , Goessling J. , Friedrichs J. , Eggers T. , Russo S. , Natale N. , Vlachos D. , Mazarakos D. , Baltopoulos A. , Vavouliotis A.
Published: February 2022

The ambition of the CA3ViAR project is to design an open test case fan that experiences instability mechanisms, which are representative for ultra-high bypass ratio (UHBR) fans of civil aircrafts, and to perform a comprehensive experimental investigation to measure aerodynamic, aeroelastic and aeroacoustic performance in a wide range of operational conditions. Experimental tests will be performed in the Propulsion-Test-Facility (PTF) of the Institute of Jet Propulsion and Turbomachinery (IFAS) of Technische Universität Braunschweig, Germany. The final objective of the project is to provide an open test case for the entire research community, with geometries, numerical and experimental results to establish a new reference for composite UHBR fan design. This will support the development of new methods and tools for the development of safer, lighter and more efficient composite fans for greener UHBR engines. In this work the preliminary design of the low transonic fan (LTF) to be used as test article, whose main requirement is to be operated in a safe and controlled way in conditions of aerodynamic and/or aeroelastic instability during wind tunnel operations, is presented. More in particular, consolidated aerodynamic design, strategy adopted to drive the structural design, flutter analysis taking into account acoustic reflection at the intake, dynamic and stress analyses, as well as aeroacoustic measurement optimization are presented and discussed. The preliminary mechanical design of composite blades and the rotor hub, together with the rotor instrumentation and related studies to embed sensors in the composite blades, are also part of this article, and complemented by manufacturing trials and demonstration tests give the full picture of all the project activities up to the preliminary design review.
Algorithm for calculation design loading cases of perspective civil aircraft
Authors: Vedernikov D. V. , Dubovikov E. A. , Guseva N. V.
Published: February 2022

This paper presents a description of the algorithm that accelerates the search for design cases of loading the perspective airframe for civil aircraft, which differ from traditional layouts. The results of validation of the algorithm for a regional aircraft with a high aspect ratio wing are presented. It was shown that the use of the proposed algorithm makes it possible to reduce the calculation time for finding the critical loading factors by at least 10 times compared to the traditional algorithm.
A hybrid approach of machine learning and expert knowledge for projection of aircraft operability
Authors: Manikar Sagar Shenoy , Jézégou Joël , Saqui-Sannes Pierre de , Asseman Philippe , Benard Emmanuel
Published: February 2022

Aircraft operational performance is a key driving factor to flight punctuality and airline profitability. The ability of a system to meet its operational requirements in terms of reliability, availability and costs is termed as ’Operability’. It is of high importance for aircraft manufacturers to project operability during the early stages of development of an aircraft in order to make trade-off studies. This paper proposes a hybrid approach of using machine learning and expert knowledge to aid the projection of aircraft operational performance during the early design stages. This approach aims to benefit from the huge amount of in-service data available from the current and past fleet of aircraft. Hence, machine learning techniques are used to learn how different technical issues and their associated maintenance activities impact aircraft operations. Expert knowledge is used to establish the default rules of the simulation model used for the operability projection. Results from machine learning are used to improve these rules allowing one to make holistic projections of the operational performance of future aircraft. This approach allows one to estimate the elapsed time in different operational states of an aircraft like flying, turn-around, etc. which can then be used to calculate different operability Key Performance Indicators (KPIs) like aircraft reliability and maintenance unavailability.
Instrumentation and Ground Testing of a Composite Elastic Wing Wind Tunnel Model
Authors: Keimer Ralf , Giannaros Efthimis , Kilimtzidis Spyridon , Kotzakolios Athanasios , Kostopoulos Vassilis
Published: February 2022

The Goal of the Project GRETEL is to build a composite elastic wing wind tunnel model. This model incorporates morphing aerodynamical structures and is to be delivered for testing in the Large Low speed Facility (LLF) wind tunnel of DNW. In order to be allowed to be tested in a wind tunnel, a ground test is required to assure the integrity of the design of the wing. In this paper a short introduction to the overall setup of the model is given including an overview of integrated sensors. A short introduction into the different configurations of the wing to be tested is given as well as the rationale for the derived test-matrix of the ground tests. The mechanical setup for the ground tests is described. There are two main tests done, on the one hand the static tests of the wingbox, on the other hand the dynamic tests for determination of modal parameters of the model in its different configurations. The static tests are done to identify mechanical responses of the model as built and compare them to the predictions of the Finite Element simulations. The method to derive the boundary conditions, i.e. loads and deformations, for the static tests from the simulation is documented and discussed. The static tests are also used to calibrate the integrated strain gauges to enable load monitoring in the wind tunnel tests. First experimental results from the ground tests are shown and discussed, comparing them to predictions from the simulation.
Manufacturing, Assembly and Integration of a Large Scale Composite Wing Wind Tunnel Model and the Design and Implementation of an associated Measurement System
Authors: Baucke Jan , Steeger Stefan , Keimer Ralf
Published: February 2022

Building a wind tunnel model with an innovative aerodynamic design including a laminar airfoil concept and morphing parts requires a suitable manufacturing and assembly plan to transfer the virtual model to concrete reality.

The contribution of the INVENT GmbH within the GRETEL consortium is the manufacturing of the main structural components of the Wing and the integration of the Wind Tunnel Model. To realize such a precise projection, the main approach is to implement a high overall accuracy of the later model by realizing a low percentage of geometry deviation already on piece part level. Beginning with a material dedicated tool design concerning cure cycle parameters and induced strain effects, for aspects of geometrical manufacturing accuracy, also suitable inspection techniques, regarding the verification of structural requirements and material conditions are implemented in the integration process at specified steps.

A further part of the integration process of the GRETEL Wind Tunnel Model is the installation of application-related measurement equipment. The Institute of Composite Structures and Adaptive Systems of the German Aerospace Center (DLR) is responsible for the design and realization of such a project customized measurement concept. For the measurement of the pressure distribution along the profile contour with various angles of attack and wing configurations during the testing, the wing is equipped with several pressure taps. Further, the measurement equipment spectrum covers also the registration of acceleration forces and mechanical loads of the inner wing structure components. This concept creates a holistic picture of the coherences between aerodynamical and mechanical dimensions for each tested configuration.

The implementation of all aforementioned aspects into the large-scale model is elucidated and discussed in the light of morphing parts of the model being delivered by another project. The integrated equipment is described and the impact of the integration into the design and assembly of the overall model is illustrated.
Development of an innovative noise generation system for turboprop aircraft fuselage testing
Authors: Dal Borgo M , Alvarez M , Blanco S , Ophem van , Denayer H , dell’Aversana P , Polito T , Staibano L , Bianco R , Peeters B , Pluymers B , Desmet W
Published: February 2022

This paper presents the development of a cabin noise testing equipment that will be used to evaluate the interior noise of regional aircraft as well as to aid the development of noise reduction techniques. The innovative noise generation system consists of three loudspeaker arrays positioned around the fuselage circumference to synthesize a pressure field that is similar to the pressure field seen by the fuselage during a flight. The acoustic pressure field generated by the loudspeakers is measured by a number of microphones scattered on the fuselage surface. These microphone signals are then fed back to the controller with the purpose of minimising the error between the target pressure field and the measured one by means of an iterative learning approach. The number and location of the microphones used in the control loop are selected through a pre-test optimisation analysis, which aims to reduce the time and cost of the set-up. A small-scale electroacoustic demonstrator has been built to develop the feedback control approach. A frequency domain multi-input multi-output feedback controller is used to replicate the random pressure field generated by the turbulent boundary layer excitation. The multi-harmonics of the propeller induced excitation are then added to the time histories of the broadband noise using a time waveform replication technique. Different arrangements of the driving signal distribution are investigated, and the results are then presented in terms of accuracy of the pressure field reproduction.
Virtual Test Approach of Titanium/Composite in Service Repair, Installed on Certified Composite Flap
Authors: Giacalone V. , Avigliano V. , Pascali L. , Orlando S. , Starace F.
Published: February 2022

Virtual test methods can contribute to reducing the great effort for physical tests in the development of composite structure and in particular on the In-service Repair. The present work describes an approach for virtual testing of titanium/composite repair based on the Building Block Approach and the Finite Elements Method. Building on a multitude of physical tests on composite panels and joints, adequate sub-models are developed, validated and the results show that the method used for the substantiation of the generic repairs (GREOs) compared with test results is conservative. This thesis intends to provide a hierarchical virtual testing approach, which enables the prediction of the failure behavior and the strength of composite In-service repairs by means of validated FEM simulation.

In particular the objective of this work will be to investigate the damage mechanisms in composite bonded skin/stringer constructions with metallic (titanium) bolted repair under uniaxial (in-plane/out-of-plane) loading conditions as typically experienced by aircraft flap skin panels.
Modelling studies of the hazards posed by liquid hydrogen use in civil aviation
Authors: Holborn P G , Ingram J M , Benson CB
Published: February 2022

As part of the ENABLEH2 project, modelling studies have been carried out to examine liquid hydrogen release and dispersion behaviour for different LH2 aircraft and airport infrastructure leak/spill accident scenarios. The FLACS CFD model has been used to simulate the potential hazard effects following an accidental LH2 leak, including the extent of the flammable LH2 clouds formed, magnitude of explosion overpressures and pool fire radiation hazards. A comparison has also been made between the relative hazard consequences of using LH2 with conventional Jet A/A-1 fuel. The results indicate that in the event of accidental fuel leak/spill LH2 has some safety advantages over Jet A/A-1 but will also introduce additional hazards not found with Jet A/A-1 that will need to be carefully managed and mitigated against.
Addressing Safety concerns in Hybrid Electric Aircrafts: In-Flight Icing Detection, Moisture Detection in Fuselage and Electrical Wiring and Interconnect System (EWIS)
Authors: Sohail Mehak , Pfeiffer Helge , Wevers Martine
Published: February 2022

Moisture - in the form of water or ice – has adverse consequences on the performance of an aircraft including wing stall, tail stall, loss of thrust, engine flameout, and material damage arising from corrosion and electrical shortcuts. During flight, a large flux of supercooled water droplets on the surface of a hybrid electric aircraft per unit time could result into icing. A prototype to detect ice accretion on supercooled aircraft surface using acoustic emissions is developed. Moreover, during descend, a large portion of frost/ice melts rapidly due to rise in temperature. If not controlled, water may seep inside a hybrid electric aircraft body through gaps in joints. Furthermore, for the problem of water ingression in the wiring of hybrid aircrafts, titanium carbonitride-polyvinyl alcohol (TiCN-PVA) composite material is placed in direct water contact to work as grid health monitoring sensor. For the problem of water ingression inside structural parts (floor, bilge, etc.), an electrically conductive epoxy – carbon black composite is fabricated, characterized using SEM, and tested for DC conductivity under dry and wet conditions. Effect of different mixing intensities on morphology of carbon black in epoxy has also been explored. Through literature survey and trial and error, an optimized method at laboratory scale for preparation of carbon black-epoxy composite material has been presented.
Opportunities of cryogenic system for hybrid electric propulsion aircraft/solar airship with LH2 and high temperature superconductor
Authors: Ravikovich Yury , Ponyaev Leonid , Holoptsev Dmitry , Domjan Rafael
Published: February 2022

A comprehensive analysis for research and development (R&D) of the technical appearance and calculation of the technical characteristics of a new hybrid electric propulsion aircraft/solar airship (HEPA) with LH2 and cryocooling system with high temperature superconductivity (HTS) can be used at any stage of the design process of a hybrid electric passenger aircraft in the implementation of the EU FUTPRINT50 international program. A new conceptual synthesis for the creation of an optimal cryogenic cooling system based on the Brayton reverse cycle using turbomachines with basic design schemes for the use of significant cryogenic power with low temperature values has been created for computational mat. models using test thermodynamic models of individual circuit elements, taking into account the efficiency of each element, their hydraulic losses in the lines of all elements of the system: calculation of hydraulic losses in the channel element, thermal control in regenerative heat exchangers with a turbocharger and calculation of a turbo expander. The real-time use of a low-capacity wireless sensor-detector or additional charging components from solar energy based on the Seebeck-Peltier effect will be more effective due to the introduction of graphene structures in the design. Experimental development of a two-stage electric compressor and a turbo expander for demonstration tests of a cryogenic cooling system in the MAI laboratory has been carried out.
Energy consumption and environmental impact of Urban Air mobility
Authors: Donateo T. , Ficarella A. , Surdo L.
Published: February 2022

Urban Air Mobility (UAM) is a recent concept proposed for solving urban mobility problems, such as urban traffic pollution, congestion, and noises. The goal of this investigation is to develop a backward model for an electric aerial taxi in order to estimate the electric consumption and the indirect emissions of carbon dioxide in a specified mission. The model takes as input the time histories of speed and altitude and estimates the power at the rotor shaft during the mission with a quasi-static approach. The shaft power is used as input for the electric drive where the motor is modelled with an efficiency map and a transfer function while an equivalent circuit model which includes aging effects is used for the battery. The emissions of CO2 are calculated as a function of the Greenhouse emission intensity and compared with that of a hybrid electric taxi performing the same mission with the same payload. A plug-in Toyota Prius modelled through the software ADVISOR is considered for the comparison. The results show that the air taxi behaves better than the road taxi not only in terms of trip time but also from the environmental point of view if the charging of the battery is performed with the emission intensity factory expected to be reached in Europe in 2025.
Layout and testing of a serial hybrid electric powertrain for a light twin demonstrator platform
Authors: Lay J , Bender A , Strohmayer A
Published: February 2022

The Project “RS hybrid 1.0” funded by the LuFo Program of the German BMWi is being executed in order to develop and investigate a serial hybrid electric powertrain to be used in a light twin aircraft, that could be exclusively operated on two electric motors. The powertrain includes a generator system, that provides energy to all power sinks like propulsors, batteries and also covers the low voltage demand of the aircraft. In the frame of this project, all necessary components are developed including the electric propulsion units, the hybrid generator system, battery modules, and DC-Link and associated subsystems.

Everything is assembled in an iron bird testbed to be able to run the powertrain in an isolated fashion, to screen for potential issues and to measure operational data. Furthermore, a comprehensive control logic for the overall system and safety management of the powertrain is being developed and tested.
Optimal sizing of hybrid electric propulsion system for eVTOL
Authors: Marzougui Taher , Neuhaus Kolja , Labracherie Laurent , Scalabrin Gianmarco
Published: February 2022

Electric propulsion unmanned aerial vehicles (UAVs) attract much attention in aviation industry, with electric vertical take-off and landing (eVTOL) aircraft tending to gain ground. The current development of hybrid eVTOL aircraft intended for urban air mobility is facing many technical challenges. Among these challenges rises the optimal sizing of its hybrid power system (HPS). The latter requires an energy management strategy (EMS). In this paper, the adopted management strategy is based on filtering techniques using frequency-separation. The EMS ensures the optimal distribution of the load power requirement between the different sources while considering their limits. In addition, the optimal sizing allows to strengthen the complementarity between sources and to indirectly reduce their mass. In this work, the studied HPS consists of a fuel cell associated with an energy storage system (ESS), composed of lithium polymer batteries (Li-Po) and supercapacitors. The onboard sources are connected in parallel on the power bus through three DC-DC converters. The results of this study are presented and discussed to highlight the relevance of the proposed approach.
Strategy for 19-seat hybrid-electric short haul air transportation
Authors: Marksel M , Kamnik R , Božičnik S , Prapotnik A B
Published: February 2022

This paper addresses a way to implement greener aviation technologies, such as hybrid-electric propulsion, into the air transportation network to respond to the increasing environmental challenges posed by growing air traffic. New routes could be established between small airports to ensure better air connectivity in Europe while also connecting disadvantaged areas and relieve congestion at hub airports. Such routes could, for example, be served by micro feeder or 19-seat hybrid-electric aircraft, which produce low or no emissions, have lower operating costs, and are more applicable to environmental constraints. To achieve this and overcome the various challenges posed by the new hybrid-electric technologies, a new strategic roadmap for short-haul air transport is needed to optimize network services with small hybrid-electric aircraft.
Reliability Considerations of the Common Unit in Hybrid Electric Propulsion
Authors: Can Sinem , Gül Cemre Gizem , Koruyucu Elif , Yildiz Melih
Published: February 2022

Since the beginning of aviation, reliability has been one of the most important elements in terms of flight safety and certification. Reliability starts from the smallest part of the aircraft and covers all components up to the entire system. The use of a hybrid-electric propulsion system has become one of the important study topics today. When hybrid-electric propulsion architectures are examined, it is seen that some elements are repeating which the authors named as common unit. This common unit is similar to the all-electric propulsion architecture and consists of a battery, battery management system, and power electronics which are used in conjunction with the hybrid-electric systems. In this study, the components and units used in the hybrid-electric propulsion system and the common unit has been examined for reliability. The common unit is proposed as a means of simplification of both the sizing and certification of the hybrid electric architecture. The reliability of the battery, battery management system, and power electronics within the system that makes up the common unit is discussed in detail for determining the reliability of the hybrid electric architecture.
A digital-based design methodology for the optimization of high-performance multi-material structures
Authors: Zschiebsch W , Filippatos A , Bohm R
Published: February 2022

A central process in composite lightweight engineering is the design of different fibre-reinforced parts. Certain steps during the design process have the potential that the overall workload can significantly be reduced, by the use of modern software tools. This often means that a compromise between optimization and increasing development costs must be found in order to balance structural complexity, number of design iteration loops and subsequent changes in the requirements. We introduce a computer-driven automation process for a multi-domain, parameter-driven design optimization. The proposed concept was built around the idea that the methodology can be used with different software tools that are already in operation for the design process of lightweight structures and therefore allows an easy implementation into already existing development chains. The developed process was successfully demonstrated by designing high-speed glass fibre rotors with respect to their structural and dynamic performance. The results showed a significant decrease in time spending during the design phase with the benefit to quickly adapt the design to subsequent changes in the optimization goal. Additionally, a wider solution space can be taken into account, which increases the quality of the optimization results.
Acceptance, Safety and Sustainability Recommendations for Efficient Deployment of UAM - Outline of H2020 CSA Project
Authors: Dziugiel B , Mazur A , Stanczyk A , Maczka M , Liberacki A , Di Vito V , Menichino A , Melo S , ten Thije J , Hesselink H , Vreeken J , Giannuzzi M , Duca G , Russo R , Witkowska-Konieczny A
Published: February 2022

The vision of a third dimension added to hitherto nearly flat urban/metropolitan transport system gained the potential to become a mobility revolution for both logistics operators and, in the near future, for passengers as well. In spite of the expected emergence of this new form of transport and respective benefits for the efficiency of the mobility system at urban and suburban scale, UAM implementation also involves unprecedented and numerous challenges for cities and for all local public and private stakeholders. The local governing bodies are expected to provide policy, regulations and guidance for the implementation of UAM and to assure its integration with the ground mobility systems as well as with other urban functionalities. Taking into account both potential benefits and associated challenges related to UAM implementation, ASSURED-UAM (Acceptance, Safety and SUstainability Recommendations for Efficient Deployment of UAM) project, funded by the H2020 Programme, aims to support that effort, by providing a multidisciplinary study on operational and policy frameworks for the process of the introduction of unmanned modes of UAM.
Learn&Fly: engaging students in STEM via aeronautics
Authors: Guedes M , Nunes N , Cláudio R , Piteira M , Dias A , Śliwa-Martinez K , Santamarina G
Published: February 2022

Learn&Fly is an Erasmus+ project aimed to demystify and to crack STEM subjects to youngsters by showing their importance and application in aeronautics. Concepts in physics and maths are explained by engagement in the construction of an aircraft, aimed to compete in a flight contest. Students must envisage, design, draw and calculate the craft, simulate its flight, make necessary design adjustments, and build it. In its first year the project attracted 121 students, between 17-21 years old; 19.5% were girls. Students work on the glider was accompanied by lectures in physics, materials, and technologies. A questionnaire was used to quantify students’ perception on project usefulness. Results show that students considered the project to be effective in improving STEM skills and career awareness, and very effective in improving soft skills. This is expected to result from the stimulating, hands-on STEM learning environment that provided access to contents, tools, and activities not usually available to high school students from the partaking countries.
How much workload is workload? A human neurophysiological and affective - cognitive performance measurement methodology for air traffic controllers
Authors: Suárez María Zamarreño , Valdés Rosa María Arnaldo , Moreno Francisco Pérez , Jurado Raquel Delgado-Aguilera , de Frutos Patricia María López , Comendador Víctor Fernando Gómez
Published: February 2022

Air traffic controllers play an important role in enabling safe, orderly, and efficient flight management within airspace. By the very nature of their work, they must make critical decisions in a time-critical environment. From a safety point of view, it would be of interest to obtain the workload thresholds (upper and lower limits) in order to define a range in which it would be safe and efficient for air traffic controllers to work. This collaboration project between CRIDA and UPM aims to obtain a methodology to define these workload limits, based on experimental affective-cognitive data and neurophysiological parameters of the performance of air traffic controllers. The workload assessment combines objective and subjective approaches. From the objective point of view, electroencephalography and eye-tracking techniques will be employed. In this paper, the first milestones achieved in the project are presented, as well as the simulation platform to be used in the experiment and the simulation-based set of exercises that has been specially designed for this project.
Cost-Optimized Avionics System - Surveillance Solution with Radar for Small Aircraft Transportation Segment
Authors: Kanovsky Petr , Korenčiak L’uboš , Adamová Eva Jošth
Published: February 2022

In this paper is explained the need for cost-optimized SAT surveillance system and described one potential approach to the solution which provides a complete protection against traffic, terrain and obstacles at an affordable price. The second part of the paper focuses on the radar. The trade-off analyses of performance, frequency bands and antenna size are described here. The goal of this paper is to highlight the need for securing the frequency spectrum for airborne radars that is under strong pressure of telecommunication lobby.
Fully Modular Robotic Arm Architecture Utilizing Novel Multifunctional Space Interface
Authors: Zeis C. , de Alba-Padilla C. A. , Schroeder K.-U. , Grzesik B. , Stoll E.
Published: February 2022

The current paradigm in space robotics is the design of specialized robotic manipulators to meet the requirements for a specific mission profile. This research aims to develop a novel concept of a modular robotic arm for multi-purpose and multi-mission use. The overall approach is based on a manipulator formed by serial connection of identical modules. Each module contains one rotational joint. The joints, rotation axis is tilted under an angle of 45° to the normal axis, which requires less stowage space compared to a traditional joint configuration. A manipulator can be reconfigured in orbit by adding or removing modules and end effectors, therefore modifying the degrees of freedom (DoF) as well as the workspace. Redundancies are introduced, since defect modules may be removed or replaced. This paper outlines the overall concept of modularization of a robotic arm. The development and mechanical design of a terrestrial demonstrator based on the multifunctional interface iSSI (intelligent Space System Interface) is presented, which is intended for OOS and OOA activities. Furthermore, a variant of the modular robotic system with 24 DoF is presented, which can be stowed in a Cubesat-sized environment. It can operate in spaces with limited accessibility and is dedicated for tasks like inspection and delicate repairs. Finally, an outlook to further research potential and future use cases for the modular robotic system is given.
Goals, tasks and technic concept of Russian flight civil supersonic jet technology demonstrator
Authors: Bashkirov I G , Chernyshev S L , Kazhan A V , Kazhan V G , Karpov E V , Shanygin A N , Shenkin A V
Published: February 2022

The fundamental difference between the new-generation supersonic civil aircraft (SST) and the existing supersonic aircraft is the need to ensure a minimum level of environmental impact. The task of achieving highly efficient faster-than-sonic flight with minimum impact on the environment requires the development and implementation of a whole set of new technical solutions and technologies for aerodynamic layout, power plant, structural design, control system, etc. The technological advance on the topic formed in Russia to date requires verification of the effectiveness, feasibility and the possibility of integrating a set of technologies and technical solutions in the real flight conditions using a flight demonstrator of SST technologies, which will increase the level of readiness of key technologies, reduce the technical risks of developing a new generation SST and provide a basis for the development of draft regulatory requirements for the environmental performance of advanced SSTs. This paper outlines the goals and objectives of such a demonstrator and discusses some of the key technologies in the interests of creating a new generation SST.
Innovative test methodology for shelf life extension of carbon fibre prepregs
Authors: Amare Constance , Mantaux Olivier , Gillet Arnaud , Pedros Matthieu , Lacoste Eric
Published: February 2022

The aerospace industry makes extensive use of composite materials in the form of fibre fabrics pre-impregnated with thermosetting resin, called prepregs. In order to minimize the resin polymerization before curing, prepregs must be stored at -18°C (0°F). There are therefore expiration dates for prepregs before use. Although manufacturers try to minimize storage time, offcuts and time out of the freezer, it is estimated that 30% to 40% of the prepregs are not used [1]. Today, recertification of expired materials is still complex and expensive, therefore it is generally chosen to send expired prepregs to landfill. The purpose of this work is to correlate physicochemical measurements with the loss of mechanical performance in order to point out and measure the real aging effects during excessive storage time. Processability, physicochemical and mechanical tests were performed in order to understand which tests are truly representative of ageing. This study was illustrated by testing on unidirectional Hexcel carbon/epoxy prepreg. Different expiry dates of this material were studied and the properties were compared. It was shown that the main observed degradation was the processability of the prepreg while mechanical performance was minimally degraded after the expiry date. This study could lead to a simpler measurement of the actual expiry rate of prepregs, which could be useful to speed up recertification procedures or to propose new scenarios to extend the shelf-life of expired prepregs [2].
Life Cycle Inventories for Engine Blisk LCA
Authors: Fricke K , Bergs T , Ganser P , Gierlings S , Albano J
Published: February 2022

The aviation industry has been growing continuously over the past decades. To ensure sustainability and competitiveness for the aviation industry sector, a full understanding of the environmental impacts is required, not only during use phase but along the entire life cycle, including “Materials”, “Processes and Resources”, “Manufacturing and Production”, “Lifetime Services” as well as “Reuse, End-of-Life and Recycling”. Core engine components, such as integral rotors (Blisks), are comprised of high value metallic alloys that require complex and resource consuming manufacturing processes. This paper will introduce an approach for Life-Cy-cle-Inventory data acquisition during Blisk manufacturing as basis for a Life-Cycle-Assessment (LCA) according to ISO 14040. A particular focus will be set on the data quality and confidence level regarding measuring, acquisition, and analysis of in- and output flows within the Blisk manufacturing process chain in scope. This includes the stages of material generation, forming processes, heat treatments, machining, surface treatments and quality assurance. A greater emphasis is drawn to selected variations on mechanical machining processes. On this basis, first results of an LCA for Blisk-manufacturing will be presented.
A novel model-based metaheuristic method for prognostics of aerospace electromechanical actuators equipped with PMSM
Authors: Matteo D.L. , Vedova Dalla , Berri Pier Carlo , Aksadi Omayma
Published: February 2022

The prior knowledge of incipient failures of primary flight command electromechanical actuators (EMAs) with prognostic algorithms can be very beneficial. Indeed, early and proper detection and interpretation of the deterioration pattern can warn for replacing the servomechanism before the actual manifestation of the abnormal behaviour. Furthermore, such algorithms often exploit a model-based approach established on the direct comparison between the actual (High Fidelity) and the monitor (Low Fidelity) systems to identify fault parameters through optimization processes. The monitor model allows the acquisition of accurate and precise results with a contained computational effort. The authors developed a new simplified monitor model capable of faithfully reproducing the dynamic response of a typical aerospace EMA equipped with a Permanent Magnet Sinusoidal Motor (PMSM). This digital twin senses mechanical and electrical faults: friction, backlash, coil short circuit, static rotor eccentricity, and proportional gain. Fault detection and identification task are performed by comparing the output signal of the reference system (real or simulated) with the one obtained from the monitor model. After that, the Genetic Algorithm is chosen as the optimization algorithm to match the two signals by iteratively changing the fault parameters to detect the global minimum of a quadratic error function. Once a suitable fit is obtained, the corresponding optimization parameters are correlated with the considered progressive failures to evaluate the system’s health status. The high-fidelity reference models analysed in this work have been previously conceived, developed, implemented in Matlab-Simulink, and validated experimentally by researchers of the ASTRA group of the DIMEAS of Politecnico di Torino.
Model validation for a transient ECS failure case in a business jet mock-up
Authors: Lindner A J M , Pschirer M , Norrefeldt V
Published: February 2022

One of the goals of the CleanSky2 Airframe project is the maturation of model based certification methods, replacing cost intensive and sometimes even impossible tests with simulations. One such impossible test scenario is the hazard assessment in case of an ECS failure in a business jet, leading to a continuous decrease of cabin temperature by conduction to the exterior environment and thus to a potentially hazardous condition for passengers and crew. Such failures have been tested on the Business Jet Cabin Demonstrator in the Fraunhofer Flight Test Facility. With the test data, a model based on the zonal approach is validated. Zonal modelling subdivides the indoor environment into typically 100-1000 zones, thus providing a local resolution of airflow and temperature distribution while still being numerically fast enough to simulate transient profiles. As the study focusses hazard conditions, subject testing is not considered possible while modelling allows for a judgement on the risk level.