Field Of Aviation Research Articles

Reducing Ground Impact Hazards of a Solar UAV Through Modelling and Analysis

The research described was conducted by a student team dedicated to finding sustainable and long-endurance systems and outlines an innovative solar panel UAV aircraft solution. Our prototype demonstrated the feasibility of the concept, while the second aircraft, currently in the design phase, aims to improve performance further and allow for extended self-powered flight time. The sustainable approach of our project addresses the growing need to reduce the environmental impact of transportation technologies. The main objective of this study is to address the requirements of the Specific Category - Civil Drones regulation, promulgated by EASA, regarding the risk associated with the impact of the aircraft on the ground in case of an in-flight failure. To address this issue, we conducted an in-depth analysis of possible failure scenarios and their consequences on the safety of the aircraft and people on the ground. Furthermore, the team developed models for risk assessment to evaluate the risk associated with solar panel UAV operation. To mitigate the risk of impact, we considered using a parachute, the effectiveness of which was analysed using a dynamic model implemented in Simulink. The analysis allowed us to evaluate the semi-controlled descent of the aircraft with the parachute attached, providing valuable information to optimize the safety system further. In conclusion, our study significantly contributes to ensuring the safety of our model in flight and on the ground through ground-impact risk management while promoting the development of sustainable and innovative solutions in the aviation field.

Fuel consumption behaviour in aggregated air traffic metrics

Currently there exist a wide variety of models that can be used to assess the fuel consumption of a single flight, from conventional models based on physics and flight performance to more innovative ones based on avant-garde techniques such as artificial intelligence. However, the quality of the fuel consumption estimated by these models usually relies strongly on the quality of data available. As consumed fuel is impacted by a wide variety of features, such as aircraft type, engine family, meteorological conditions, flight path, etc, the more information available, the more accurate the estimations will be.However, having access to such granulated data is not always trivial and, moreover, the computational cost that could be derived from assembling data coming from different agents in the aviation field (airports, airlines, manufacturers, meteorological stations), plus the processing of the data and afterwards the computation of a refined fuel consumption model will be very high. The work presented here has been developed within the framework of the project E.R.A. (Environmentally Responsible Aviation) funded by Red.es, and it presents an extensive analysis on how consumed fuel and carbon dioxide emissions estimations could be made with limited access to information. Moreover, the aim is to be able to prove that for aggregated metrics, that being a set of flights and not a single flight, the consumed fuel can be easily estimated thus helping accounting for the carbon dioxide emissions that are produced at a global level.

Features of scientific research work of future aviation specialists

The article presents the peculiarities of research work of future aviation specialists. It is noted that higher education institutions in the aviation field pay considerable attention to ensuring the scientific and research component of the use of modern educational technologies for the professional training of future specialists. The purpose of the study was the analysis and peculiarities of the research work of aviation institutions of higher education, aimed at the formation of research skills and professional skills. The methods of research were the analysis and generalization of scientific literature on the organization of research work in higher education, ICAO documents regulating the flight safety management system for air transport. Features of research work for students of higher education at aviation institutions are singled out, in particular: application of the problem-based learning method through the analysis of aviation regulatory documents and investigation materials of aviation events; simulation of real professional situations through a business game (imitation simulation), where the student is given the opportunity to be a pilot, air traffic controller, dispatcher-instructor, aviation shift leader, etc.; student conferences as an opportunity to present professional research work; simulator (practical) training; the practically oriented character of the educational program – the involvement and use of the work experience of aviation specialists-practitioners. The criteria for ensuring the effective organization and implementation of research work of future aviation specialists are summarized, which is the complexity, consistency and comprehensiveness of learning and use of methods and technologies of conducting scientific research, implementation of their results, the continuity of research work according to training courses, the logic of the complication of methods, types and forms of scientific creativity

Study on working mechanism and performance of deep groove seal at high temperature and high speed in mixed lubrication

The deep groove seal is a kind of mechanical seal with millimeter depth grooves on the end face of the sealing ring, widely used in aviation and nuclear fields. However, its working mechanism and sealing performance are still unclear. In this research, a fluid-solid-thermal coupling numerical analysis model at high temperature and high speed in mixed lubrication is established to solve these problems. Mechanism analysis indicates that deep grooves cause circumferential waviness of micron level on the end face, strongly affecting the sealing performance. A quantitative characterization method is proposed, solving the characteristic parameters and analytical expression of deep groove seal waviness, so that the deep groove seal can be approximately equivalent to the waviness seal and be explained by the law of the waviness seal. The sealing performance can be controlled through the design of groove parameters. The results have been verified by the experiment. The fluid-solid-thermal coupling model and characterization method of equivalent waviness parameters for the deep groove seal proposed in this article provide a theoretical basis for further study of the mechanism and performance of the deep groove seal.

Experiment and Simulation on the Ferrofluid Boundary Deformation and Fluctuation Characters of a High-Speed Rotary Seal

Abstract A ferrofluid seal is a rotary seal widely used in the chemical industry, shipbuilding, aerospace, aviation, and other fields, demonstrating various advantages, such as high reliability, low wear, and low leakage rate. The reason for sealing is that the ferrofluid ring isolates the sealed gas from the atmosphere. Hence, boundary deformation and fluctuation are two significant factors to consider for the design of a ferrofluid seal. However, the ferrofluid boundary is wrapped in the shell and pole shoe, which poses a challenge in direct observation. In this paper, an experimental ferrofluid rotary seal device is presented, which can be used to monitor the boundary changes at different rotational speeds and pressure differences. According to the simulation result, the boundary fluctuation affects the pressure transfer and causes the sealing performance to deteriorate. The ferrofluid boundary obtained through the experiment is essential for an in-depth investigation into the rotary seal failure mechanism for improving the design of the ferrofluid rotary seal.

Method of 3D Coating Accumulation Modeling Based on Inclined Spraying.

In the process of repairing the surface of products in aviation, aerospace, and other fields by spraying, accurate 3D cumulative-coating modeling is an important research issue in spraying-process simulation. The approach to this issue is a 3D cumulative-coating model based on inclined spraying. Firstly, an oblique spraying layer cumulative model was established, which could quickly collect the coating thickness distribution data of different spray distances. Secondly, 3D cumulative-coating modeling was conducted with the distance between the measuring point and the axis of the spray gun and the spraying distance between the measuring points as the input parameters, and the coating thickness of the measuring point as the output parameter. The experimental results show that the mean relative error of the cumulative model of the oblique spraying layer is less than 4.1% in the case of a 170~290 mm spraying distance and that the model is applicable in the range of -80~80 mm, indicating that the data on the oblique spraying coating proposed in this paper is accurate and fast. The accuracy of the 3D cumulative-coating model proposed in this paper is 1.2% and 21.5% higher than that of the two similar models, respectively. Therefore, the approach of 3D cumulative-coating modeling based on inclined distance spraying is discovered, demonstrating the advantages of fast and accurate modeling and enabling accurate 3D cumulative-coating modeling for spraying process simulation.

Stray Light Analysis and Suppression for an Infrared Fourier Imaging Spectrometer

To improve the accuracy of infrared radiation characteristics measurement in the aviation field, an infrared Fourier transform imaging spectrometer based on a double-swing solid angle reflector was designed. This imaging spectrometer operates in the 3–5 μm wavelength range and has a field of view of 1.7° × 1.7°. This article presents a comprehensive analysis of the system’s stray light and also studies the impact of external stray light on the imaging quality, along with the influence of internal stray light on the interference effects and the spectral resolution. It also present the design of a hood that suppresses the point source transmittance of the external stray light down to the order of 10−4. Based on this, we propose a method that incorporates the introduction of wedge and inclination angles. Additionally, a numerical range is provided for the addition of these angles on the beam splitter mirror and compensation plate. This ensures the effective suppression of any internal stray light. This study fills the gap in the knowledge about Fourier transform imaging spectrometers operating in the mid-infrared band for aviation applications, and proposes a suppression method suitable for interference systems, which is also suitable for Fourier transform imaging spectrometers based on other types of interferometers. This study broadens the application field of Fourier transform imaging spectrometers in stray light, and has great significance to promote the development of Fourier transform imaging spectrometer.

Quantitative Detection of Defects in Multi-Layer Lightweight Composite Structures Using THz-TDS Based on a U-Net-BiLSTM Network.

Multi-layer lightweight composite structures are widely used in the field of aviation and aerospace during the processes of manufacturing and use, and, as such, they inevitably produce defects, damage, and other quality problems, creating the need for timely non-destructive testing procedures and the convenient repair or replacement of quality problems related to the material. When using terahertz non-destructive testing technology to detect defects in multi-layer lightweight composite materials, due to the complexity of their structure and defect types, there are many signal characteristics of terahertz waves propagating in the structures, and there is no obvious rule behind them, resulting in a large gap between the recognition results and the actual ones. In this study, we introduced a U-Net-BiLSTM network that combines the strengths of the U-Net and BiLSTM networks. The U-Net network extracts the spatial features of THz signals, while the BiLSTM network captures their temporal features. By optimizing the network structure and various parameters, we obtained a model tailored to THz spectroscopy data. This model was subsequently employed for the identification and quantitative analysis of defects in multi-layer lightweight composite structures using THz non-destructive testing. The proposed U-Net-BiLSTM network achieved an accuracy of 99.45% in typical defect identification, with a comprehensive F1 score of 99.43%, outperforming the CNN, ResNet, U-Net, and BiLSTM networks. By leveraging defect classification and thickness recognition, this study successfully reconstructed three-dimensional THz defect images, thereby realizing quantitative defect detection.

Stackable and Deployable Laser‐Induced Graphene Layers Toward the Flexible Manufacturing of Smart 3D Honeycombs with Multifunctional Performance

AbstractSmart honeycombs are becoming the novel structural strategy for next‐generation devices and equipments. Unfortunately, traditional surface‐coating, structural immersing, and 3D printing approaches still face significant challenges in combining structural customization and performance multifunctionality. Herein, a brand‐new processing strategy is developed to construct graphene‐based smart honeycombs by stacking and deploying laser‐induced graphene (LIG) layers with alternatively inserted adhesives. Through tuning key parameters, various LIG‐enabled smart honeycombs (LIG‐HC) can be assembled with scalable areal dimension and thickness, variable cell sizes and shapes, as well as patternable graphene clusters. By further understanding the process‐dependent structural stability and electrical conductivity, multifunctional characteristics are systematically explored, including anisotropic mechanical, electrical, piezoresistive, and electromagnetic performance. To finally demonstrate the unique honeycomb multifunctionally applied in fields of aviation, an intelligent LIG‐HC enabled aircraft‐wing model is representatively constructed for performing anti‐/de‐icing, high‐temperature warning, flame retardancy, pressure and vibration monitoring, as well as electromagnetic shielding and stealth.

Investigation of the stress–strain state of a composite blade in ANSYS WorkBench

In this paper, the static strength of a UAV blade made of composite material was calculated. Composite materials have an advantage over traditional materials (metals and alloys) in the field of aviation - gain in weight, low sensitivity to damage, high rigidity, high mechanical characteristics. At the same time, the identification of vulnerabilities in a layered structure is a difficult task and in practice is solved with the help of destructive control. Composite materials available in the ANSYS materials library were used in the modeling: Epoxy Carbon Woven (230 Gpa) Prepreg woven carbon fiber in the form of a semi–finished prepreg impregnated with epoxy resin carbon fiber with Young's modulus E=230 GPa and Epoxy Carbon (230 Gpa) Prepreg is a unidirectional carbon fiber prepreg impregnated with epoxy resin with a Young's modulus E=230 GPa. Modern software products, such as ANSYS WorkBench, allow comprehensive investigation of the layered structure. Several variants of blade designs with different fillers as the median material were investigated. The forward and reverse destruction criteria based on the Tsai-Hill theory were used. The influence of gravity was not taken into account. It is shown that the developed blade design meets the requirements. Balsa wood, pine, aspen and polyurethane foam were chosen as the middle material of the blade. Pine and aspen wood were selected according to the criteria of their availability and having the lowest density. The materials library of the ANSYS WorkBench software package used does not have characteristics for all of them, so the characteristics of the selected materials (pines and aspens) were added manually. For modeling and calculations in the ANSYS WorkBench program, such characteristics as density, axial elastic modulus, Poisson's coefficients, shear modulus and tensile and compressive strength limits are required.

When Nurses in an Emergency Situation Look for a Medical Item But Fail to See It.

Emergency department nurses may fail to see medical items in emergency cart drawers, such as syringes and tubes, while handling emergency situations, which can often contribute to a delay in managing the case. This is a phenomenon known as Looked-but-failed-to-see (LBFTS) and occurs when the observer fails to detect a visible visual stimulus among various other stimuli. LBFTS is a group of human errors, including inattentional blindness (IB), satisfaction of search, and biased search processes, and is associated with constraints on human visual processing. LBFTS has been studied extensively in the fields of aviation, military, radiology, and road safety; however, the role of LBFTS in hospital ED has generally been overlooked. Hence, a key aim of this study was to investigate the possibility of the occurrence of LBFTS among ED nurses while searching for a particular medical item during a real-life emergency. An observational cross-sectional blinded study was conducted to determine the occurrence of LBFTS in a real-life visual search task during resuscitation cases in ED. The A-B-C (antecedent-behavior-consequence) observation and recording naturalistic observation technique was used. A total of 45 ED nurses who were assigned to either the crash cart or the intubation trolley at the time of data collection agreed to participate and were included in the analysis. The results revealed that LBFTS accounted for 66% of the cases where emergency items were brought from another location. Participants missed seeing an item, although the item was directly in front of their eyes. Factors such as the perception of cognitive workload at the time of data collection positively impacted the increase in LBFTS (P = .021). Taken together, the results of the present study and recent visual studies support the occurrence of LBFTS among nurses working in ED. Devising successful strategies to reduce this phenomenon could translate directly into saved lives.

Analysis of Springback Characteristics of Bending Unloading for Stainless Steel tubes

Stainless steel tubes are widely used in piping systems in aviation, aerospace and other high-tech fields because of their high strength, excellent corrosion and high-pressure resistance, and good resistance to high-temperature oxidation. This paper takes 304 stainless steel pipe as the research object, based on ABAQUS finite element platform, the springback behaviour of stainless steel pipe in the process of precise bending and forming has been studied in depth. The results show that: pipe bending unloading bending springback angle increases with the increase of the bending angle. The results of the study have important theoretical and practical significance for improving the accurate forming and springback of stainless steel tube bending.

In situ creation of aramid fiber surface coating with polymerizable deep eutectic solvents and their interfacial bonding properties with rubber

AbstractThe coating was created on the surface of aramid fibers (AFs) by solution dip‐coating and in situ UV curable method, using a polymerizable deep eutectic solvent (PDES), dissolved poly(ethylene imine), and poly(ethylene glycol) diacrylate (PEGDA). Fourier transform infrared spectroscopy and thermogravimetry confirmed the successful construction of the coating on the AF surface, which accounted for 12%–17% of the total fiber mass. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images revealed a 2 μm increase in fiber diameter and a maximum fiber surface average roughness (Ra) of 263.7 nm when the polyethyleneimine content was 0.5% (AF‐PDES‐0.5). Based on these results, H pull‐out samples of fiber/rubber composites were fabricated. The results indicated that the H pull‐out force of AF‐PDES‐0.5 samples increased by 109.74% than that of untreated fiber, and reached 12.92 N of the maximum strength. In summary, the method is simple, rapid, non‐polluting, capable of continuous, and intelligent construction of coatings on the surface of AF. Thus, making it highly promising for application in the field of aviation tires.Highlights Using PDES, green, and low‐carbon preparation processes. Solution dip‐coating and UV reaction for improved reaction speed and workability. Quantitative of interface thickness and modulus using EDS and AFM.

An Intercontinental Study of Employee and Employer Human Factor Issues Put Up in Aerospace and Aviation Industry

Through my recent swot i understood that the topic of human factor is continually gaining higher level of visibility in all the spheres of aviation and aerospace engineering; however, the elements that drive future human interactions with emerging technologies have room for further studies. A considerable amount of effort has been invested in improving the physical motor skill-centric design considerations. Emerging aerospace organisations face the challenges of properly interpreting and implementing the emerging human factor requisites. A lot of the emphasis in the average design organization is typically centred around the hardware and software components, the system performing to its stated requirements, meeting the reliability specification, and the system’s impact safety of flight but lower is the overall focus on all the facets of human in the loop irrespective of employee and employer. A mastery of human factors (HF) in such complex systems as air traffic management (ATM)and air traffic control (ATC) is crucial to maintain the efficiency and safety of the systemand the well being of those working within,it is an very fundamental issue specially in the field of aviation and aerospace industry.

A comprehensive assessment method for manned confined space layouts taking into account operational posture comfort supported by artificial intelligence algorithm

Given its specialized design application, the layout design of confined spaces for human occupancy has a significant impact on the efficiency of operators, especially in the design processes aimed at aviation, aerospace, navigation, and other significant engineering fields. The influence of operational posture on layout comfort is crucial, yet existing assessment methods have limited considerations for the impact of operational posture on layout comfort. Therefore, this study proposes a layout decision support method that integrates posture recognition, simulation, and simulation-based comfort comprehensive assessment. By combining intelligent recognition technology, simulation technology, and comprehensive evaluation methods, it aims to provide a highly reliable comprehensive evaluation result for layout design and decision recommendations. To validate the effectiveness of the method, we conducted a comfort experimental evaluation involving seven individuals in the layout design of human-occupied confined spaces at Northwestern Polytechnical University. The results indicate that the proposed method offers a more objective and comprehensive means for layout design and optimization. This Improvement method not only addresses the deficiencies in existing spatial layout evaluation methods and provides a theoretical basis for architectural layout planning evaluation but also offers new perspectives and methodological support for scientific layout design and planning.

Research on Measurement Technology of Coefficient of Thermal Expansion of Honeycomb Structure

Honeycomb structure is widely used as the main sandwich layer of load-bearing structure in aviation, aerospace and other fields because of its light weight and high strength. Under some service conditions, the deformation of the honeycomb structure affected by high and low temperature will affect the overall mechanical performance of the structure. Therefore, accurate evaluation of the thermal expansion performance of the honeycomb structure becomes the key to structural design. However, the existing measurement methods of thermal expansion coefficient mainly have problems such as the hollow structure cannot be effectively contacted, the area of the grid optical target is limited and difficult to detect. In view of the above conditions, in this paper, a method for measuring the thermal expansion coefficient of honeycomb structure is proposed, and the measurement system is built, and the thermal expansion performance of honeycomb structure is effectively obtained by testing the honeycomb structure. At the same time, the measurement accuracy of the system is verified by using standard test pieces. The experimental results show that the method has high measurement accuracy.

Self‐healing polymers for aviation applications and their impact on circular economy

AbstractPolymers have swiftly replaced conventional metallic materials in aviation due to their lightweight and easy processability. Usages of polymers are presently mostly limited to non‐critical components. Flight safety is paramount in aviation and overrides all other factors. The aviation industry is averse to the usage of polymeric materials in critical component applications owing to the nature of failure being catastrophic. The review has covered various polymeric component failures and their root cause reasons. To overcome the inherent weakness in polymers currently used, a strategy to mimic nature is being explored by researchers. Self‐healing polymers can overtake metals if coupled with safe fail technology. Such materials have additional advantages in terms of enhanced longevity and ultimate life cycle. This review critically analyzed various factors driving research and development of self‐healing material for aviation applications. Various extrinsic and intrinsic self‐healing materials have been reviewed in the present work. Composites with an extrinsic self‐healing mechanism possess good healability and strength and can potentially replace current materials. Further, candidate polymeric materials with intrinsic self‐healing capability for the aviation field are extensively reviewed. Various aviation‐grade polymers like epoxy, Poly(methyl methacrylate), polycarbonate, and elastomeric materials with possible chemistries of intrinsic healing like Diel‐Alder reaction, Shape memory assisted self‐healing and covalently adaptable networks have been critically examined. Authors believe that extrinsic self‐healing technology is mature enough for use in the secondary structure of aircraft. At the same time, present technologies of intrinsic materials are not mature enough for flight safety reasons in aircraft; however, they are candidate materials for UAVs. Fast‐growing aviation field, coupled with the entry of UAVs, calls for environmentally sustainable material support. Therefore, this review explores materials within the sphere of high mechanical properties coupled with a low environmental impact.

Transfer Learning-Based Remaining Useful Life Prediction Method for Lithium-Ion Batteries Considering Individual Differences

With the wide utilization of lithium-ion batteries in the fields of electronic devices, electric vehicles, aviation, and aerospace, the prediction of remaining useful life (RUL) for lithium batteries is important. Considering the influence of the environment and manufacturing process, the degradation features differ between the historical batteries and the target ones, and such differences are called individual differences. Currently, lithium battery RUL prediction methods generally use the characteristics of a large group of historical samples to represent the target battery. However, these methods may be vulnerable to individual differences between historical batteries and target ones, which leads to poor accuracy. In order to solve the issue, this paper proposes a prediction method based on transfer learning that fully takes individual differences into consideration. It utilizes an extreme learning machine (ELM) twice. In the first stage, the relationship between the capacity degradation rate and the remaining capacity is constructed by an ELM to obtain the adjusting factor. Then, an ELM-based transfer learning method is used to establish the connection between the remaining capacity and the RUL. Finally, the prediction result is adjusted by the adjusting factor obtained in the first stage. Compared with existing typical data-driven models, the proposed method has better accuracy and efficiency.

Design and Manufacture Method of Aviation Face Gear With High Load-Bearing Based on Gear Skiving Process

Abstract Face gear drive has been widely investigated in the aviation field as a power split device on the helicopter main reducer. However, high-speed and heavy-load condition makes the face gear prone to tooth surface pitting, leading to deterioration of transmission performance. To improve the load-bearing capacity of face gear, this paper proposes a design and modification method based on gear skiving process for face gear drives. First, gear skiving mathematical models for a face gear pair are established, and a continuously profile-shifted modification method is presented based on these mathematical models. Then, the load-bearing capacity of the modified face gear pair is minutely analyzed and discussed through contact analysis. The contact stress of the modified face gear is reduced by 47.78% on the right side and 41.1% on the left side compared with an unmodified face gear. Finally, gear skiving experiments and meshing performance tests of face gear pairs are conducted. The measurement results show consistency with the calculation results. Thus, the proposed design and continuously profile-shifted modification method based on the gear skiving process is feasible and contributes to load-bearing capacity improvement.

Research on Fabrication of Phononic Crystal Soft-Supported Graphene Resonator.

In aviation, aerospace, and other fields, nanomechanical resonators could offer excellent sensing performance. Among these, graphene resonators, as a new sensitive unit, are expected to offer very high mass and force sensitivity due to their extremely thin thickness. However, at present, the quality factor of graphene resonators at room temperature is generally low, which limits the performance improvement and further application of graphene resonators. Enhancing the quality factor of graphene resonators has emerged as a pressing research concern. In a previous study, we have proposed a new mechanism to reduce the energy dissipation of graphene resonators by utilizing phononic crystal soft-supported structures. We verified its feasibility through theoretical analysis and simulations. This article focuses on the fabrication of a phononic crystal soft-supported graphene resonator. In order to address the issues of easy fracture, deformation, and low success rate in the fabrication of phononic crystal soft-supported graphene resonators, we have studied key processes for graphene suspension release and focused ion beam etching. Through parameter optimization, finally, we have obtained phononic crystal soft-supported graphene resonators with varying cycles and pore sizes. Finally, we designed an optical excitation and detection platform based on Fabry-Pérot interference principle and explored the impact of laser power and spot size on phononic crystal soft-supported graphene resonators.