Aviation Components Research Articles

Design and Research of Wireless Passive High-Temperature Sensor Based on SIW Resonance

The temperature of advanced components in aviation and aerospace fields is difficult to obtain timely. In this study, we aimed to investigate microwave backscattering technology combined with the theory of substrate integrated waveguide and resonant cavity to design a wireless passive temperature sensor and explore its potential in this field. We employed silicon carbide and aluminum ceramic as the substrate to make sensors. The interrogation antenna was designed to test the sensor, which could completely cover the working frequency of the sensor and had good radiation characteristics. Based on the test results, the silicon carbide sensor was capable of bearing a temperature limit of about 1000 °C compared to the alumina sensor. From 25 °C to 500 °C, its sensitivity was 73.68 kHz/°C. Furthermore, the sensitivity was 440 kHz/°C in the range of 501 °C to 1000 °C. Moreover, we observed the surface of this sensor by using the scanning electron microscope, and the results showed that the damage to the sensor surface film structure caused by long-term high temperature is the major reason for the failure of the sensor. In conclusion, the performance of the silicon carbide sensor is superior to the alumina sensor.

A novel approach for characterization of delamination and burr areas in drilling FRP composites

Drilling of aerocomposites is very critical process in the production of aviation components. The defects in the drilled holes can lead to high stresses on the rivet and the component and thus, catastrophic failure of the structure. The economics of drilling-induced defects is significant, particularly considering the various stages related to the part as it reaches the final assembly line. In this study a novel, simple, inexpensive, and accurate AutoCAD Image Processing (ACIP) technique was developed to evaluate the damaged area in drilling FRP composites. Drilling operations are performed on woven GFRP composites without back-up plate. Scanning electron microscopic examination was conducted on representative specimens to clarify the different mechanisms of chip and burr formation with respect to fiber orientation and the instantaneous velocity vector of the cutting edge. The results revealed that the developed ACIP technique has an amazing accuracy without missing any details in the computed delamination and burr areas in comparison with the other methods. Because of the non-dimensional delamination parameters are not account the damaged area, in some cases they seems to be not suitable for representing the measured values, which considerably increased the importance of this study.

3DWoodWind: robotic winding processes for material-efficient lightweight veneer components

Winding processes are known from fiber composite technology for highly resistance lightweight components for aviation. These fiber-based processes work predominantly with synthetic composites made of carbon or glass fibers. For the construction industry, these additive processes are very promising and resource-efficient building processes, but they are still hardly used in timber construction despite the very high level of digitalization and technical development. The 3DWoodWind research project uses a continuous strip of thin veneer as a sustainable alternative as its application material. Its natural fibers are intact, continuous, and tensile. In the project, three-dimensional winding processes were developed for material-efficient hollow profile lightweight components made of wood. We describe the material system, composed of suitable combinations of veneers and adhesives, and develop computational design methods for filament layout and robotic fabrication methods. We also show an open-source prototype development method, necessary for efficient prototyping. Through several fabrication case studies, we demonstrate the capabilities of the production process, and investigate suitable architectural applications. These hollow lightweight components could save large amounts of material in timber construction and serve as a substitute for concrete or steel components in the future. We conclude by discussing possible applications in the construction industry and future research possibilities.

Hydrogenated orange oil: A waste derived drop-in biojet fuel

Orange oil was extracted by steam distillation from the peels of oranges produced as waste in the orange juice factories. This raw orange oil, a potential source for biojet fuel, was analysed by FT-IR and GC-MS, and compared with distilled orange oil and pure d-limonene, which is its main chemical constituent. Both distilled orange oil and d-limonene were hydrogenated under reaction conditions (from 3 to 18 bar) which are mild enough to be industrially feasible, to improve its properties, especially to reduce their sooting tendency. Some important properties such as density, viscosity, heating values, lubricity, flash point, crystallization onset temperature, and smoke point were measured for hydrogenated orange oil and d-limonene (as a reference for comparison) at different conversions. These hydro-biofuels were blended with Jet A1 to check their suitability as biobased blending components for aviation. Based on the results obtained for the main aviation fuel properties, it is concluded that up to 15 vol% of partially hydrogenated orange oil could be blended with Jet A1 without any significant drawback for the performance of the actual airplanes. Flammability reduction systems would be needed to further increase the blend proportion of this drop-in biofuel in Jet A1.

Experimental damage tolerance evaluation of thick fabric carbon/epoxy laminates under low-velocity and high-velocity impact and compression-after-impact

Impact experiments of thick fabric carbon/epoxy laminate specimens, with small thickness ratio, are conducted at distinct energy levels and thicknesses to characterise the damage process. These specimens and loading conditions are representative of a new generation of critical structural components in aviation, such as wing spars, landing gear beams and fittings, that are increasingly being made entirely from composites. The tests address the need to better understand the damage process for specimens with a small thickness ratio since existing experimental impact data for large thickness ratio (thin laminates) may not be directly applicable. Two energy levels, two different fabric layups and two impact methods (drop-weight and gas-cannon) were used. Data from high-speed cameras were processed in a novel way, providing the force during impact. C-scans and micrographs were used to characterise damage. The results show that specimens with a thickness ratio of 5 (20 mm thick) experience more bending compared to specimens with a ratio 2.5 (40 mm thick). For gas-cannon impacts, this results in a higher delaminated area. The drop-weight impacts show almost no differences in damage size for the thickness range analysed. The influence of layup on the global impact response is negligible, but locally it can result in significant variations in dent depth. The dent depth scales linearly with the impact energy and the delaminated area linearly with the impact velocity. There is no clear correlation between the compression-after-impact failure mechanisms and the residual strength. Impact damage, at the current energy levels, showed a minimal reduction of residual strength.

Multi-performance optimization on hard-turning for improving the product quality of high-chromium stainless steel

As steel continues to expand its current range with stronger, more ductile automotive brands, automakers are turning their attention to this. The future of vehicle weight reduction does not require a shift to alternative material systems and a complete overhaul of existing manufacturing infrastructure. When it comes to enhancing surface quality and dimensional accuracy in hardened steel, hard turning technology has been shown to be quite effective. In order to do this, it is employed in some important aviation components where the material hardness surpasses 45 HRC, such as 300 M ultra high strength steel, for finishing operations. In this context, this study focuses on optimizing cutting conditions in hard turning to reduce surface roughness, roundness, energy consumption, tool wear, and increase MRR. To this end, an experimental design (DoE) is used to study the effect of specimens with processing conditions such as cryogenic, heat-treated and obtained, cutting speed (V), feed rate (f), depth of cut (D), and heat treatment for hard turning. The L9 orthogonal matrix was performed using multiple response gray-relational analysis (GRA), and ANOVA was performed with individual characteristics and their effects.

Tailoring the strengthening-toughening behavior of the MoSi2 film by doping trace solute Au

Although the high hardness and wear resistance of transition metal silicides (TMSi) are widely used in protective films, overcoming the contradiction between hardness and toughness still faces huge challenges. Here the magnetron sputtering was used to introduce trace solute Au atoms into the MoSi2 to form a solid solution structure. X-ray diffraction and high-resolution transmission electron microscopy were used to characterize the microstructure of Mo-Si-Au film. In addition, hardness and toughness enhancement by solute Au was investigated the film through the combination of experimental and theoretical studies. The results show that the hardness and fracture toughness of Mo-Si-Au (Au/Mo atom ratio, R = 0.10) film is 15.4 GPa and 2.52 MPa m1/2, respectively. Compared with MoSi2, the hardness and toughness are increased by 41.3% and 68.0%, respectively. Density Function Theory calculations and electronic structure analyses further indicate that the increase in the hardness of the solid solution Mo-Si-Au film may be related to the increase in bulk modulus, C33, and C11. The increase in toughness is mainly due to the strengthening of the metal bonds in MoSi2 after doping a small amount of solute Au. The introduction of trace solute Au atoms in TMSi provides a new reliable scheme for overcoming the contradiction between hardness and toughness. As part of this research, a protective coating based on TMSi will be expected to be applied to aviation components.

Prospects for the application of the product life cycle system by means of the planned preventive maintenance module on the example of aviation and agricultural components

The paper describes an approach to the development of a functional software module within the subsystem of planning, rationing, preventive, routine maintenance, with the functions of accounting for the time of turning operations in the manufacture of machine parts for various purposes, in the general technological chain of the software complex of interacting ERP/MRP/CAD/CAM/CAE technologies of the enterprise, including forecasting both the time of resource operation and the production of necessary components, in order to support manufactured aviation, agricultural and other products throughout the life cycle.

Concept, Essence and Characteristics of Aviation Personnel in the System of the Aviation Component of the Internal Affairs of Ukraine

The scientific research is focused on studying the concept and essential characteristics of aviation personnel in the system of aviation component of Internal Affairs of Ukraine. The relevance of the article is due to global trends, which are associated with the fact that aviation is becoming a key element in the development of many countries. The use of airspace for various purposes is becoming an increasingly important and sometimes a priority direction in the political, military and social strategy of most countries, including Ukraine. Legal issues of interaction between the Ukrainian system of internal affairs and the aviation system are important for Ukraine in addition to specific domestic economic, technical and legal problems in this area. A legal issue in regard to the organization of the movement of aircraft is a systemically interconnected group of special legal principles of air law. A special place in the system is occupied by the regulation of labor relations of aviation personnel. Accordingly, addressing the problems that arise in the framework of labor relations in the field of aviation is one of the important components of the analysis of aviation as a component of the internal affairs system. The concept of aviation personnel in both civil and state aviation has been studied in the framework of this article. The purpose of theoretical research is a systematic review and clarification of the concept of "aviation personnel for further analytical work and in-depth study of existing problems that may arise in the system of aviation component of Internal Affairs of Ukraine. Certain concepts were generalized; key differences between aviation and aviation ground personnel were identified; and basic conceptual imperfections were identified through the synthesis and analysis.

A novel cold expansion process for improving the surface integrity and fatigue life of small-deep holes in Inconel 718 superalloys

Hole cold expansion is an effective anti-fatigue manufacturing technology, which is widely used in hole strengthening of aviation components. In this paper, a novel small-deep hole (with the diameter less than 2 mm and the depth greater than 10 mm) cold expansion process, called the multi-spherical bump rotating cold expansion process (MBR-CEP), was proposed and verified by experiments on the Inconel 718 superalloy. The MBR-CEP tool with multi-spherical bumps produced by the laser texturing process (LTP) was first designed, and the MBR-CEP with different expansion degrees (δ = 2.1%, 2.6%, and 3.1%) was conducted on small-deep hole specimens. The surface integrity of the small-deep holes before and after the MBR-CEP in the inlet, middle, and outlet areas was studied. Results showed that compared with the small-deep hole after reaming, the hole treated by the MBR-CEP with different δ formed a plastic deformation layer with a maximum depth of 32.73–85.54 μm, a minimum surface roughness of 0.115–0.138 μm in Ra, and a compressive residual stress (CRS) layer with a depth of 0.39–1.077 mm. In addition, the CRS increased by up to 84%, and the microhardness increased by up to 13%. The microstructure evolution on the top surface and sub-surface of the small-deep hole wall was observed by transmission electron microscopy (TEM), which showed that nanocrystals with the size of 48–90 nm and a large number of dislocations and deformation twins formed. Finally, the effectiveness of the proposed process was verified by fatigue tests with different δ at 400 °C. The average fatigue life increased by 3.66 and 8.05 times under δ = 2.1% and 2.6%, respectively. The fatigue fracture surface was examined with scanning electron microscopy (SEM), which revealed that low surface roughness and existence of a plastic deformation layer could effectively reduce the probability of crack initiation.

A comprehensive combustion chemistry study of n-propylcyclohexane

Alkylated cycloalkanes are vital components in gasoline, aviation, and diesel fuels; however, their combustion chemistry has been less investigated compared to other hydrocarbon classes. In this work, the combustion kinetics of n-propylcyclohexane (n-Pch) was studied across a range of experiments including pressurized flow reactor (PFR), jet stirred reactor (JSR), shock tube (ST), and rapid compression machine (RCM). These experiments cover a wide range of conditions spanning low to intermediate to high temperatures, low to high pressures at lean to rich equivalence ratios. Stable intermediate species were measured in PFR over a temperature range of 550–850 K, pressure of 8.0 bar, equivalence ratio (φ) of 0.27, and constant residence time of 120 ms. The JSR was utilized to measure the speciation during oxidation of n-Pch at φ of 0.5–2.0, at atmospheric pressure, and across temperature range of 550–800 K. Ignition delay times (IDTs) for n-Pch were measured in the RCM and ST at temperatures ranging from 650 to 1200 K, at pressures of 20 and 40 bar, at φ=0.5,1.0. In addition, a comprehensive detailed chemical kinetic model was developed and validated against the measured experimental data. The new kinetic model, coupled with the breadth of data from various experiments, provides an improved understanding of n-Pch combustion.

Brittle-ductile transition in compliant finishing of HVOF sprayed hard WC-Co coating

WC-Co coating with nanolevel surface finish is required in some special components in aviation, automobile and forming industries. In this study, compliant finishing of WC based coating is carried out using an in-house fabricated wheel based SAG tool. Theory of contact mechanics and the interactions of active abrasive particles with the workpiece surface are considered to develop a material removal rate (MRR) model. The brittle-to-ductile transition of WC-Co coating is investigated during compliant finishing with diamond abrasive pads having different particle size. It is observed that the material is purely removed through ductile mode when 6 μm polishing pad is used and the critical chip thickness for brittle to ductile transition lies in the range of 60–100 nm. Moreover, the lower wheel compression and higher wheel speed can slightly enhance the possibility of ductile machining. A low surface roughness of 21 nm is achieved using multistep compliant finishing operations with decreasing abrasive particle size in a sequence. The residual stress of the finished coating is found to be −78 ± 8 MPa which is almost 28% of the ground surface. The cross-section of the finished coating is analysed and no appreciable sub-surface damage is detected.

Research on the Manufacturing Quality of Co-Cured Hat-Stiffened Composite Structure.

The stringer-stiffened structure is widely used due to its excellent mechanical properties. Improving the manufacturing quality of stringer-stiffened structure which have complex geometry is important to ensure the bearing capacity of aviation components. Herein, composite hat-stiffened composite structures were manufactured by different filling forms and bladders with various properties, the deformation of silicone rubber bladder in co-curing process was studied by using the finite element method. The thickness measurement at different positions of the hat-stiffened structure was performed to determine the best filling form and bladder property. Moreover, in view of the detection difficulties in R-zone of stringer, numerical simulation was performed to get the sound pressure and impulse response of at the R-zone of stringer by Rayleigh integration method, and an effective equipment which could stably detect the manufacturing quality of R-zone was designed to verify the correctness of sound field simulation and realize the detection of stringer. With the optimum filling form and bladder properties, hat-stiffened composites can be manufactured integrally with improved surface quality and geometric accuracy, based on co-curing process.

Thermomechanical pretreatment of Al-Zn-Mg-Cu alloy to improve formability and performance during creep-age forming

Abstract Thermomechanical treatment is often conducted to improve the formability and performance of high-strength aluminum alloys simultaneously. This paper presents an improved creep-age forming (CAF) processing technology that combines thermomechanical pretreatment and CAF. The proposed processing technique is expected to enhance the forming efficiency and comprehensive properties of Al–Zn–Mg–Cu alloys subjected to CAF. Creep-aging behavior and properties of the 7150 aluminum alloy undergoing retrogression and re-aging (RRA) with 3 % pre-strain treatment was experimentally investigated in this study. Results obtained reveal greater creep deformation in thermomechanically pretreated samples than in those pretreated using RRA or 3 % pre-strain exclusively. Mechanical properties, electrical conductivity, and exfoliation corrosion of creep-aged samples with thermomechanical pretreatment were closely match those of the traditional RRA-treated sample. Microstructure observation discovered η2 phase in the creep-aged RRA pretreated sample in addition to conventional GP / η’ phase, η phase and coarse and discrete grain-boundary precipitates. Low concentration of solutes in matrix in RRA pretreated sample impeded dislocation motion less and pre-strain-induced dislocations increased the creep strain significantly. Moreover, hardening effect of η2 phase and dislocation hardening compensated the strength loss due to precipitation coarsening. The proposed thermomechanical pretreatment process provides an appropriate initial temper for CAF of Al–Zn–Mg–Cu alloys, thereby improving the creep formability and comprehensive properties remarkably. The findings of this study could aid in the development of CAF technology for Al–Zn–Mg–Cu alloys, especially in terms of manufacturing aviation components.

Новые методы атомно-абсорбционного определения содержания металлов в авиационном и автомобильном бензинах

New methods for direct atomic absorption determination of lead and lithium as antiknock additives components in aviation and automotive gasoline in the concentration ranges 100–1700 (Pb) and 2.5/0.25–100 (Li) mg/L have been developed. To overcome the difference in analytical signals for samples and standard solutions due to concentration values and matrix effects the proper sample dilution and the addition of the blank as pure reagent hydrocarbons mixture in the solutions have been offered. The methods have high precision, are simple and may be recommended for gasoline quality control and identification procedures.

On the Issue of a Comprehensive Evaluation of the Effectiveness of Using Airship Systems As a Means of Rescuing Space Crews.

This paper presents approaches to selecting criteria and conducting a com-prehensive evaluation of the comparative effectiveness of using manned innovative dirigibles in the search and rescue system for space crews in various climatic and geographical zones. The evaluation can be carried out for existing and prospective means that provide the ground, sea and aviation components of nominal and emergency search and evacuation of crews of new-generation manned transport spacecraft in the conditions of the Vostochny cosmodrome, which are characterized by special natural and geographical parameters.

Synthesis of high-titer alka(e)nes in Yarrowia lipolytica is enabled by a discovered mechanism

Alka(e)nes are ideal fuel components for aviation, long-distance transport, and shipping. They are typically derived from fossil fuels and accounting for 24% of difficult-to-eliminate greenhouse gas emissions. The synthesis of alka(e)nes in Yarrowia lipolytica from CO2-neutral feedstocks represents an attractive alternative. Here we report that the high-titer synthesis of alka(e)nes in Yarrowia lipolytica harboring a fatty acid photodecarboxylase (CvFAP) is enabled by a discovered pathway. We find that acyl-CoAs, rather than free fatty acids (FFAs), are the preferred substrate for CvFAP. This finding allows us to debottleneck the pathway and optimize fermentation conditions so that we are able to redirect 89% of acyl-CoAs from the synthesis of neutral lipids to alka(e)nes and reach titers of 1.47 g/L from glucose. Two other CO2-derived substrates, wheat straw and acetate, are also demonstrated to be effective in producing alka(e)nes. Overall, our technology could advance net-zero emissions by providing CO2-neutral and energy-dense liquid biofuels.

An error analysis and optimization method for combined measurement with binocular vision

The accurate measurement of surfaces of large aviation components is vital for the assessment of manufacturing and assembly quality of such components. To satisfy the measurement requirement of large-size components, most current researches pay more attention to combined measurement methods utilizing different measuring instruments, but the related researches on error analysis and optimization methods are not taken enough attention. This paper proposes a combined laser-assisted measurement method with feature enhancement techniques, and it also develops an error propagation model of the main factors affecting the overall measurement error in detail. Firstly, the surface of a large-size component is measured by the measurement system at multiple stations. Secondly, a control point coordinate system is established as a bridge to unify all local measurement data into the global coordinate system. To improve the overall measurement accuracy, the pixel extraction error as a key factor causing the overall measurement error is analyzed in detail. Next, the error propagation model is established, and some optimization strategies of layout for minimizing measurement error and transformation error are researched. Finally, experiments are carried out to verify the effectiveness of the proposed method. The results show that the measurement error of the proposed method reaches 0.073% and 0.14% with a 1D standard ruler and a flat plate, respectively.

Development of the Concepts for Providing Close Air Support

Abstract The main objective of the study is to trace the perceptions of the task of an aviation component to provide direct aviation support to both ground and naval forces. Part of the study is devoted to tracing the combat experience gained during the assignment by the Bulgarian Air Force in the final combat operations against the Wehrmacht during the Second World War 1944-1945. The state of the conceptions at the present stage regarding the accomplishment of the task in conducting defensive and offensive battles and operations is also considered. Emphasis is also placed on the development of the perceptions of the task in the armies of the United States and Russia.

Modeling of the transport and production complex in the growing of agricultural crops, taking into account the aviation component

Studies of the transport and technological process of growing crops revealed that it is a complex dynamic system. It is proved that the complexity of this system consists in the presence of a large number of heterogeneous subsystems, including transport, which is an important component for growing crops. Due to the system approach to the study of transport support of the crop growing process, it became possible to identify functional features of using ground and aviation vehicles. The properties of each stage of the growing process and involvement of certain types of vehicles are determined. The scheme of transport support of the crop growing process is developed and the influence of the aviation component at certain stages in the introduction of resource-saving No-till technology is determined. Experimental studies showed that the use of aviation transport contributes to the introduction of resource-saving No-till technology by minimizing the mechanical processing of sown areas, which reduces the anthropogenic load on the soil. The developed mathematical model for analyzing the use of the transport and production complex in growing crops allows making a rational choice of ground and aviation vehicles, depending on the parameters of technologies, types of crops. Thus, there is reason to argue that it is possible to make timely and reasonable management decisions in the organization and management of agricultural production in order to maximize profits