bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Clustering of Material Inspection Data for Highway Construction Projects Based on Agglomerative Hierarchical Clustering
Authors: Zhang Qun , Fang Shaohong , Ye Haolong 
Published: March 2024

Abstract
In large-scale highway construction projects, the project implementers will carry out detailed testing of various material indicators used in the project. By processing and analyzing these material testing data, we can reasonably classify large-scale highway construction projects, so that each project implementer can better manage the quality of the materials, which will greatly help all parties to strengthen the quality control of the project and improve the level of project management. This study first preprocesses the material testing data to obtain a structured data set suitable for data analysis. Then statistical features are constructed for the features in the dataset, including maximum, minimum, mean, median and standard deviation, to improve the performance and accuracy of the model. Next, the clustering hierarchical clustering method is applied for classification and the classification results are visualized in the form of dendrograms. Finally, through the comparison of performance analysis and clustering evaluation indexes, it is concluded that the classification of works into 3 or 4 categories according to material performance is in line with the actual level of engineering quality.
Enhancing Flame Retardancy and Thermal Insulation Performance of Silicone Rubber Composites Using Silicon Carbide
Authors: Lou Xu , Zang Chongguang , Pan Hongwei 
Published: March 2024

Abstract
This study focuses on modifying silicone rubber using silicon carbide (SiC) to enhance the flame retardancy and thermal insulation properties of the composites. The study characterizes the thermal stability, mechanical properties, and flame retardancy of the composite materials. The results demonstrate the effective improvement in thermal stability achieved by incorporating SiC into the silicone rubber composites. At a SiC addition level of 6 wt.%, the composite material shows optimal thermal stability with an initial decomposition temperature of 487°C, which is 84°C higher compared to the pure matrix. Additionally, the SiC/SR composites system exhibits a char yield of 72.13% at 900°C, representing an approximately 9% increase compared to the pure SR matrix. Simultaneously, the incorporation of SiC significantly enhances the flame retardancy of silicone rubber. At a SiC addition level of 10 wt.%, the LOI (Limiting Oxygen Index) value increases by 10.5% to reach 30.4%, surpassing the non-additive sample. Moreover, the UL-94 classification of the composite material is V-0, meeting the standard for flame retardant materials.
Effect of Graphene Particle Diameter on Mechanical Properties of Graphene Composite Material
Authors: Ni Guanyun 
Published: March 2024

Abstract
In order to improve the mechanical properties of alloys and broaden their application fields, high-performance metal matric composites have received more and more attention. Graphene has excellent mechanical properties and is often used as a reinforcing phase for various composite materials. However, as the reinforcing phase of the composite, the number, shape, and size of graphene have a significant effect on the overall mechanical properties of the composites. Therefore, the influence of graphene particle diameter on the mechanical properties of graphene particle reinforced metal matrix composites was studied in this paper. By establishing a series of finite element models, we simulated the mechanical behaviour of composite materials under static tension loading. The relationship between graphene particle diameter and material mechanical properties is revealed.
Effect of La2O3 adding on Properties of SiC Porous Ceramic Support
Authors: Qiu Shuang , Xue RiDong , Dai Xinchao , Wu Chengjun , Deng Xiangyun 
Published: March 2024

Abstract
In this paper, 80-90 grains of SiC as the main raw material, doped La2O3 into the binder composed of potassium feldspar, kaolinite and quartz, and then graphite and activated carbon as pore-making agents to prepare silicon carbide porous ceramic carrier. The effects of doped La2O3 content on the bending strength, porosity and filtration pressure drop of porous SiC ceramics were studied. The results show that the formation of mullite phase and the bending strength of SiC porous ceramics can be improved by adding proper amount of La2O3. Under the sintering temperature of 1300°C for 90 minutes, when the content of La2O3 in the binder is 2.5wt%, the comprehensive performance is the best, the porosity is 21.5%, the bending strength is 53.5MPa, and the filtration pressure drop is low.
Overview of safety challenges associated with integration of hydrogen-based propulsion systems for climate neutral aviation
Authors: Dimos Dimitrios , Graaf Stefanie de 
Published: March 2024

Abstract
Electrification through hydrogen-based fuel cells as well as hydrogen combustion in gas turbines is a key strategy in aviation for achieving substantial reduction of emissions. However, this transition presents multifaceted challenges. Besides the development and improvement of technologies required for such hydrogen-fuelled aero engines, the safety of hydrogen storage and distribution systems on aircraft is paramount. Challenges associated with hydrogen in terms of its material properties, the design and selection of components for the conditioning and distribution, as well as the system design are being presented and discussed in this work. This includes the consideration of high diffusivity, flammability and reactivity of hydrogen and the consequences of these traits: hydrogen embrittlement, hydrogen-induced cracking and leakage, for instance. The challenges elaborated in this work are pertinent to both hydrogen fuel cell-based propulsion systems and hydrogen combusting gas turbines. Design considerations were derived and are being outlined in this work. These are transferable to applications in other industries such as automotive and stationary power plants. The need for novel rigorous safety protocols to enable a sustainable future in aviation is being highlighted.
H2Electra – a platform for comparative analysis of integration concepts for hydrogen-based electric propulsion in regional aircraft
Authors: Graaf Stefanie de , Bahrs Victor , Tarbah Noah , Kazula Stefan 
Published: March 2024

Abstract
Over the past decade numerous novel concepts for electric flight have been elaborated. Each unique in its own way and based on various assumptions and technological advances projected for the future. Within each concept design decisions have to be made on component level, propulsion system level and aircraft level. In order to be able to evaluate and analyse both, advanced components technologies and innovative propulsion system architectures, as well as to understand the effect of each design decision, a common baseline platform has been developed to allow for comparative analyses.
This work presents such a platform with the hydrogen-based electrified regional aircraft concept called H2Electra. The iterative design process developed for this purpose is presented. It allows for a holistic approach to the development of an aircraft, its electrified propulsion system as well as the sizing of the components therein. Two propulsion system integration concepts are being considered in the evaluation: one partially fuselage-integrated and one nacelle-integrated. Challenges and trade-offs between the two concepts were analysed and evaluated, with safety and reliability being key design and decision-making metrics, alongside block-fuel efficiency and power density. In particular, the design decision on a suitable bus voltage and its effect on the powertrain sizing and integration were investigated.
Gappy POD model for Structural Compliance of the Wing of a Civil Tilt-rotor
Authors: Amendola Gianluca , Cinquegrana Davide , Quagliarella Domenico , Belardo Marika , Chiariello Antonio 
Published: March 2024

Abstract
The selection of the most critical load conditions is an extremely important topic as it allows the design and structural verification to be limited to a limited subset of conditions that envelop the operational thousands of the Design Limit Load (DLL) book without necessarily having to apply a direct approach. Often, thousands of analyses are performed by a Detailed Finite Element Model (DFEM, including model loading, post-processing and full stress and buckling analysis) taking a long time with a higher probability of error. This work describes the effort to set up a surrogate model of a composite wing, which aims to supply, accurately and efficiently, the structural response of the wing to several solicitation loads that populate the DLL. The surrogate model is defined by employing the Proper Orthogonal Decomposition technique (POD), trained on partial knowledge of data. The snapshots collected are composed of load solicitations and, limited to a subset of wing elements, stress and strain states resulting from the structural response to the relative load solicitation in a numerical analysis. Gappy-POD algorithm is set up to deal with this lack of data in the querying stage when only the solicitations are known. The surrogate model training starts with a selection of loads from the DLL, while its reliability is increased by iteratively adding further FEM analyses based on error maps opportunely defined.
Structural Analysis of a Large-scale Model for the Wind Tunnel Test of a Multiadaptive Flap
Authors: Sіcіm Demіrcі Mürüvvet Sinem , Pecora Rosario , Orhan Kaya Metin 
Published: March 2024

Abstract
Innovative studies on morphing wing structures with the highest potential to improve aerodynamic performance on large aircraft are running under the CleanSky2 platform to validate the morphing architectures on true-scale demonstrator through ground and wind tunnel tests. Research activities have been conducted to develop a revolutionary multi-modal camber morphing flap to enhance the aerodynamic behaviour of a new generation of regional aircraft within this challenging framework. The design and validation of the intelligent architecture capable of different morphing modes required for low-speed (take-off/landing) and high-speed (cruise)conditions. To enhance the significance and applicability of the wind tunnel test campaign, a significant scale factor of 1:3 was selected for the test article. In this study, general layout of the mechanical model and FE analysis performed both inner and outer flap will be presented. A comprehensive structural analysis of the flap test article was conducted to ensure the safety and effectiveness of the conceived mechanical solutions. Linear static analyses were performed using the finite element (FE) method within the Ansys Workbench® environment. These analyses aimed to assess the adequacy of the mechanical solutions and validate the test article’s structural integrity.
Rapid, iterative design approach for preliminary configuration of a High Altitude, Long Endurance aircraft
Authors: Deuschle Lukas , Kirchner Edgar , Obert Lara , Aust Erwin , Stoll Luca , Marr Niels , Grieb Prof. Dr.- Ing. Markus 
Published: March 2024

Abstract
This paper presents a rapid iterative design approach, used to develop a preliminary configuration of an Unmanned Aerial Vehicle (UAV), which is to perform a High-Altitude, Long Endurance (HALE) mission. First, based on a set of requirements, an initial aircraft concept is developed.
The rapid iterative design approach revolves around an energy-based flight profile simulation, which is updated with an improved aerodynamic model of the aircraft during every iteration. An aircraft configuration is defined by a set of constant parameters. A corresponding flight profile consists of an altitude and velocity profile, as a function of time. The behaviour of the aircraft is simulated based on the specified flight profile.
For sizing the aircraft components exposed to the airstream, the aerodynamic design phase aims to create an airframe which achieves the performance outlined in the flight performance simulation, utilizing the obtained aircraft parameters. Using the geometric data, a 3D-model of the aircraft is created, which is essential for the aircraft’s weight and balance calculations and for determining the airframe shape exposed to the airflow. A Computational Fluid Dynamics (CFD) simulation is conducted to obtain the actual aerodynamic characteristics of the airframe. If the performance requirement of the flight performance simulation is not met, another iteration of the aerodynamic design phase is required.
The design framework stands out due to its rapid iteration capability, accessibility, and straightforward application, making it particularly advantageous for educational settings in which students engage with aircraft design. The approach aims to offer satisfactory results for an initial aircraft conceptualization.
This design framework emerged from the DLR Design Challenge 2023, an annual competition hosted by the German Center for Aerospace Research, where student teams develop preliminary aircraft designs. This years challenge tasked the teams with designing an aircraft system to restore internet coverage over a disaster-affected region. The described approach was used to develop the Sentinel System of the DHBW Ravensburg team. However, the simulation and development process is not limited to applications within this challenge.
An event-driven link-level simulator for validation of AFDX and Ethernet avionics networks
Authors: Vera-Soto Pablo , Villegas Javier , Fortes Sergio , Pulido José , Escaño Vicente , Ortiz Rafael , Barco Raquel 
Published: March 2024

Abstract
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.
Simulation of an Aerospace Electrohydraulic Servomechanism, with different Coulomb Friction models
Authors: Alimhillaj P , Lamani L , Dalla Vedova M D L 
Published: March 2024

Abstract
The contemporary design of flight control systems demands the utilization of intricate models for the in-depth analysis of individual components or subsystems. Conversely, there is a parallel need for more foundational and synthetic models that offer sufficient accuracy, specifically tailored for preliminary design, monitoring, or diagnostic purposes.
This paper centers on electro-hydraulic servomechanisms designed for aeronautical applications, emphasizing their contemporary significance. These systems play a crucial role, particularly in primary flight commands characterized by precise position servo control.
The great variety of configurations and applications, their complexity and the criticality that characterizes this servomechanisms, deemed appropriate to devote particular attention to their modeling and the development of numerical simulation systems models that are versatile and reliable (flexible and easily applicable to different real systems but capable of providing realistic simulations). In particular, in this work are presented two innovative Coulomb friction models which are applied through MATLAB/Simulink block diagram structure to the model of the electrohydraulic servomechanism. The two friction models are foreseen to overcome the problematic of standard models for the friction, giving more realistic results, increasing the accuracy of the simulations.
Investigation of noise reduction effects of individual and combined geometrical modifications on UAM propeller blades
Authors: Skrna D , de Rosa Jacinto da Silva M , Berens M 
Published: March 2024

Abstract
The development of a future transportation concept in cities may also include transportation of passenger and cargo at various altitudes in order to reduce the load on the ground infrastructure. This is known as urban air mobility (UAM), facilitated by the application of electrical vertical take-off and landing (eVTOL) vehicles. Public acceptance is required with regard to safety aspects in densely populated areas, but also in terms of noise emissions. As with almost any aircraft, the propulsion systems, in most cases the propeller blades, are the main source of noise generation. In literature, experimental and numerical results for geometric blade modifications for the purpose of noise reduction are provided only for small diameter propellers. This paper investigates the individual features at larger diameter propellers by means of numeric aeroacoustic simulations with OpenFOAM. The modifications include serrations of the trailing edge, leading edge tubercles and blade tip adaptations. Moreover, the combination of those features is investigated in a parameter study for various rotational velocities and several flight modes. The key effect, namely a reduction of broadband noise, can be observed for several cases, but the strength of it varies. An optimization process is necessary to obtain an efficient noise reduction for all operating conditions of a particular aircraft design.
Experimental investigation of blade-shaped riblets for drag reduction on UAV applications
Authors: Bliamis C , Panagiotou P , Vlahostergios Z , Misirlis D , Yakinthos K 
Published: March 2024

Abstract
This study presents an experimental investigation of blade-shaped riblets for drag reduction in unmanned aerial vehicle (UAV) applications. UAVs have gained significant attention since they can perform various missions, including surveillance, reconnaissance, and package delivery. However, their aerodynamic performance, specifically the high drag associated with their exposed surfaces, remains a key challenge for enhancing their efficiency and extending their flight endurance. To address this issue, riblet geometries are proposed as a potential solution, which can reduce the turbulent skin friction drag by up to 8%. The experimental investigation involves wind tunnel testing of blade-shaped riblets, with various spacing-to-height (s/h) ratios and constant groove cross-sectional area (Ag). The riblets are designed for application on the wing, empennage, and fuselage surfaces of a UAV. The investigations are performed on a flat plate for various flow conditions, including different freestream velocities, to evaluate the drag reduction effectiveness of the riblet configuration. The drag force is measured using a force balance system and flow visualization techniques are employed to assess the position where the boundary layer has transitioned to fully turbulent. The results demonstrate the drag-reducing effect of blade-shaped and trapezoidal riblets and the different performances observed for the various s/h ratios. The cases with s/h=1 result in the smallest drag coefficients, while the cases with s/h=2 have significantly increased drag values, compared to the smooth flat plate, due to the increased wetted surface area. These findings highlight the potential of riblets as an effective drag-reduction technique for UAV applications, enabling increased endurance and/or enhanced payload capacity.
Enabling Human-Autonomy Teaming in Aviation: A Framework to Address Human Factors in Digital Assistants Design
Authors: Bjurling O , Müller H , Burgén J , Bouvet C J , Berberian B 
Published: March 2024

Abstract
The introduction of artificial intelligence (AI) tools in aviation necessitates more research into human-autonomy teaming in these domain settings. This paper describes the development of a design framework for supporting Human Factors novices in considering human factors, improving human-autonomy collaboration, and maintaining safety when developing AI tools for aviation settings. Combining elements of Hierarchical Task Analysis, Coactive Design, and Types and Levels of Autonomy, the design framework provides guidance in three phases: modelling and understanding the existing system and associated tasks; producing a new function allocation for optimal Human-Autonomy Teaming (HAT); and assessing HAT-related risks of the proposed design. In this framework, designers generate a comprehensive set of design considerations to support subsequent development processes. Framework limitations and future research avenues are discussed.
Air Travel Itinerary Market Share Prediction using Artificial Intelligence
Authors: Serrano-Ortega A , Cano-González Á , Toledo-Garrote A , Chamoso P 
Published: March 2024

Abstract
The widely used Quality Service Index (QSI) model estimates air traffic by considering attributes such as capacity, connectivity, and travel time, which impact an itinerary market share (MS) in the origin-destination (OD) market. To determine itinerary attractiveness, the conventional QSI model combines these features, weighting them based on their significance and generates a score for each option. The key is therefore to select the optimal combination of weighted attributes that are able to forecast the MS with the desired accuracy. However, traditional QSI models rely on expert knowledge and assume that the traffic generation and allocation is always based in the same market principles, hindering their ability to generalize and identify new features. To address this, the present work, which is part of a research project entitled ERA funded by Red.es, introduces a generalized rationale based on Artificial intelligence using historical data, a challenge that has been faced in the early stages of the project. This approach enables the identification and understanding of key features in the aviation traffic and the development of a forecasting model capable of capturing more complex feature relationships.
Analysis of Film Cooling for a 3kN LOX/butane Demonstrator Engine
Authors: Ashford Z A R 
Published: March 2024

Abstract
Regenerative cooling has been the primary cooling method for every modern launch vehicle engine, except for the Viking: a film-cooled (with ablative throat) N2O4 / UH25 engine used on the first stage of the Ariane rockets 2-4. Despite this, film-cooling as a stand-alone cooling method has traditionally been considered insufficient for the high combustion temperatures and long burn times associated with launcher engines. This study explored the feasibility of a solely film-cooled engine at the demonstrator scale (3 kN), as a prototype for a lightweight launcher engine. A wide range of liquid oxygen (LOX)/butane engines were modelled and from this a relationship was determined to predict chamber wall temperature for a given oxidiser-to-fuel ratio (O/F), chamber pressure, and amount of film cooling. Notably, this equation was found to apply to both a 3 kN and a 30 kN engine. Numerical modelling of engine specific impulse (Isp) using this equation then found the conditions yielding optimal engine performance.