bluuebunny/crossref_metadata_2025_split huggingface dataset:
Super-cooled droplet impact and ice accretion on an aircraft engine nacelle lip
Authors: Wang Ziqi , Guan Ning , Lu Yongxiu , Gao Xiang 
Published: January 2024

Abstract
This manuscript concentrated on the icing phenomenon on the lips of an engine nacelle. Numerical simulation was employed to establish the airflow, supercooled droplet impact, and engine nacelle ice accretion models. The study investigated the airflow field near the lip, the characteristics of supercooled droplet impact, and the ice accretion near the lip under different flight conditions. The computational results indicated that due to the effects of nozzle contraction and flow extraction, a low-pressure, high-velocity, and low-temperature region appeared on the inner side of the lip, leading to ice accretion on the nearby wall. The maximum collection efficiency on the lip surface at 20, 000 ft was slightly higher than that at 10, 000 ft, with a maximum value of approximately 0.6. In the computed conditions of this study, as the flight altitude and Mach number increased, the ice thickness on the lip surface increased and the ice spread inward, posing a significant risk of ingestion after detachment.
Failure analysis of right-front wheel hub rim of nose gear of a cargo aircraft
Authors: Li Chunguang , Zhang Xiaoyue , Feng Yanpeng , Tang Haijun 
Published: January 2024

Abstract
Following a post-flight inspection of a cargo aircraft upon landing, it was discovered that the right front wheel hub rim of the nose gear had experienced a fracture. In order to determine the cause behind this fracture, a comprehensive analysis was conducted on the hub, encompassing macro-micro-morphological observation, energy spectrum analysis, microstructure examination, and mechanical testing. The findings revealed the presence of a lengthy oxide defect at a stress concentration point located on the inner corner of the hub rim. Fatigue cracks emerged at this defect site, exhibiting signs of fatigue growth, ultimately leading to high-cycle fatigue fracturing at the hub rim position. It is suggested that quality control should be strengthened during the production process of wheel hubs to avoid defects forming. Further inspection of the transition position of the wheel flange during maintenance and repair is needed to find the crack as soon as possible.
Analysis of force and wear mechanism of shield hob under conventional working conditions
Authors: Shen Dong , Cao Quan , Qi Zhizheng , Xu Xiaodong 
Published: January 2024

Abstract
In order to study the force and wear of the hob during the excavation of the composite formation, Abaqus simulation is used to simulate the stress state of the hob when breaking the rock and soil. Based on the abrasive wear mechanism, a prediction model of radial wear amount and linear wear rate suitable for a single hob is derived, and verified with actual engineering data. The results show that the normal force plays an important role in the rock breaking of the hob, and the penetration degree and the cutting edge radius are important factors affecting the normal force of the hob. When the penetration degree increases, the normal force and radial wear of the hob will increase, but the increase of radial wear will slow down due to the width of the cutting edge. Working with the “small-large-small” penetration law not only improves the boring efficiency but reduces the loss of the hob. Therefore, the study provided references for the hob wear and optimization research.
Design and accuracy analysis of new cable network topology configuration of umbrella-shaped deployable antenna
Authors: Zhang Tingrui , Ji Youzhi , Wang Bo 
Published: January 2024

Abstract
To reduce the back-pillow effect of the cable-net antenna and improve the accuracy and error uniformity of the umbrella antenna surface, a new cable-net topology of the umbrella antenna is proposed. Firstly, the cable network segment is divided to obtain a new topological configuration of the umbrella antenna. Secondly, starting from the cable net accuracy calculation method, the Gauss-Legendre integral method is used to calculate the accuracy of the umbrella sky clue network surface method. Finally, the new cab-net configuration is compared and analyzed by example, and it is of great significance to improve the accuracy of the antenna surface and improve the uniformity of error distribution.
Failure analysis of one main wheel hub bolt fracture of A320 aircraft
Authors: Ma Xiaoming , Zhang Xiaoyue , Li Chunguang , Wang Yulin , Chen Li 
Published: January 2024

Abstract
When an aircraft was performing flight tasks, it was found that one connecting bolt of No. 3 main wheel was missing during the short stop inspection. The bolt uses 148 ups and downs this time, and the use time is significantly lower than normal. It is inferred that the high probability of its fracture is not caused by long-term use, and it is speculated that the fracture reason is related to the quality of the bolt itself. Material analysis showed that there were no obvious abnormalities in the bolt material, and slight scratches were found near the bolt. The bolt is fatigue fracture and the fracture position is located at the transition arc position. Microscopic observation shows that there is a V-shaped groove on the side of the crack source area, but because the gasket is no longer in the installation position, it cannot directly determine the installation problem of the gasket. It is recommended to optimize the installation process and NDT (No Destructive Testing, NDT) detection process in the future.
Optimization design and experimental study of axial-swirling bubble generator
Authors: Chen Dekai , Tang Wenxian , Lu Yalin , Gao Hushan , Chen Kaiyun 
Published: January 2024

Abstract
On the basis of the venturi tube bubble generator, a new axial swirl bubble generator is designed, and the numerical simulation of the bubble generator with different number of three baffles is carried out by using Fluent software, and it is found that the three-lobed type is significantly better than the two-leaf type and four-leaf type in the swirl velocity and core swirl area, and the response surface optimization method is used to optimize the key structure and analyze the interaction influence. The results show that the parameter that can most affect the bubble diameter is the throat diameter, followed by the expansion angle, the contraction angle has the least effect, the optimal parameters are 21.9°, the throat diameter is 5mm, and the expansion angle is 13.8°, and the accuracy of the numerical model is verified by experimental comparative analysis, and finally the influence of gas-liquid flow on bubble size is studied with the help of high-speed camera.
Analysis and experimental study on flow characteristic and rangeability of plug control valve
Authors: Geng Shengtao , Wang Wei , Ming You , Chen Fengguan , Yu Hongbing , Ye Xiaojie , Ni Yulong , Xu Tingting 
Published: January 2024

Abstract
According to the specific structure of the plug valve, a method for estimating the rated flow coefficient was proposed. Based on a variable diameter flow passage model, flow coefficient tests for four plug control valves with different specifications were carried out, and the experimental data were analyzed and researched. The results show that: (1) The proposed estimation method for calculating the rated flow coefficient of the plug valve, in which the deviation range is -6.58%∼4.10%, meets the requirement of the standard IEC 60534-2-4-2009 as not exceeding ±10%; (2) Due to the manufacturing errors, the actual inherent flow characteristic of the plug control valve is between equal percentage and parabola. The larger the flow capacity is, the more equal the flow characteristic gets; (3) The plug control valve has an outstanding feature of high rangeability, which can be up to R=979 and is obtained based on the flow coefficient test data.
Calculation and analysis of a ventilation and cooling scheme for aircraft brake assembly
Authors: Li Chuang , Yao Qian , Xu Wenjie , Yang Yi 
Published: January 2024

Abstract
The slow cooling of brake assembly of civil aircraft is one of the major constraints on the operational efficiency of the aircraft. Aiming at the engineering problem of brake carbon heatpacks in flight cooling, this article proposes a ventilation and cooling scheme for aircraft brake assembly, which is based on the original configuration of the main landing gear compartment of the aircraft. By adding the design of the intake duct and exhaust grille, external cooling airflow is introduced to cool the brake carbon heatpacks during flight. This article confirms the cooling effect through simulation calculations and experimental data. This article can provide a reference for the ventilation and cooling design of civil aircraft brake assembly.
Numerical simulation analysis of the temperature field in induction heating-assisted flow drilling of the 7075 aluminum alloy
Authors: Zhang Kai , Wan Hailang , Min Junying , Lin Jianping 
Published: January 2024

Abstract
Flow drill riveting (FDR) is a unique method designed for the joining of disparate materials such as aluminum alloys and carbon fiber-reinforced polymers (CFRPs). The success of FDR hinges on the frictional penetration process executed by the blind rivet. When deploying FDR for the joining of high-strength materials, a substantial penetration force often arises, leading to deformations in the workpieces and potentially causing failure in the joining process. To mitigate the excessive penetration force, the use of induction heating to pre-warm the workpiece before the FDR process has been suggested. This led to the development of the induction heating-assisted flow drill riveting (IHFDR) method. In this work, a FEM model was built for the IHFDR penetration process. This model was specifically designed for the AA7075-T6 sheet, utilizing the ABAQUS software. Induction preheating impact on the temperature of the workpiece during the rivet penetration process was scrutinized. The analysis revealed that the workpiece’s peak temperature during the rivet penetration process was elevated due to induction preheating. Furthermore, it was observed that as the preheating elevated the workpiece temperature, the rate of increase for the peak temperature lessened.
Study on mechanical properties of nickel-based tungsten carbide cladding layer based on plasma cladding process
Authors: Du Kunda , Xu Lipeng , Lv Zhifeng , Fan Weichao , Wu Zenglei , Zhang Ruikong 
Published: January 2024

Abstract
The Ni60+60%WC cladding layer was prepared on the surface of Q355 steel by plasma cladding process under different cladding currents. Through a metallographic microscope, microhardness test, shear strength test, and friction and wear test, the relationship between solidification structure and mechanical properties of Ni60+60%WC cladding layer was analyzed. Through experiments, it is concluded that when the current is 150-170 A, there is a good metallurgical bond between the cladding layer and matrix, and the bonding effect improves with the increase of the cladding current. The metallurgical bonding effect is poor when the current is 130 A or 140 A. When the cladding current is high, the hard tungsten carbide particles in the cladding layer show varying degrees of sinking phenomenon. Simultaneously, with the escalation of the cladding current, the tungsten carbide (WC) particles within the cladding layer decrease in size, and the ablation phenomenon becomes more obvious. When the cladding current is 130-160, the hardness of the obtained cladding layer increases to varying degrees compared to the matrix, with the highest hardness obtained with a current of 160 A. With an increasing distance from the cladding layer surface, there is an observed trend of hardness initially increasing and subsequently decreasing. In addition, as the cladding current goes up, the shear strength of the cladding layer goes down. The trend of abrasive resistance of cladding layers is the same as that of hardness. The abrasive resistance of the cladding layer increases with the increase of hardness.
Research on the heat treatment process of Q235A steel
Authors: Wang Yan 
Published: January 2024

Abstract
Q235A steel was heat treated by using different heat treatment process parameters. The microstructure after heat treatment was observed microscopically and its hardness was measured. The results indicated that the complete austenitization temperature has not been reached at 850°C and even under water-cooled conditions, only a very small amount of martensite can be obtained. After water cooling at 900°C, 950°C, and 1000°C, lath martensite can be obtained, which made the hardness of water cooling significantly higher than that of oil cooling, air cooling, and furnace cooling. The quenching temperature of 1000°C was too high and the microstructure obtained after water cooling, oil cooling, air cooling, and furnace cooling was relatively coarse, which was not suitable as the heating temperature for heat treatment of Q235A steel.
Effect of heat treatment on microstructure and properties of bimetallic band saw blade
Authors: Xue Tinglian , Liu Yan , Li Guimao , Zhao Gusiyang 
Published: January 2024

Abstract
Quenching and tempering treatment experimentswere conducted on the bimetallic band saw blades,and theeffect of quenching and tempering processes on the microstructure and properties of the band saw blades were studied. The results indicate that with increasing quenching temperature, the solid solution strengthening effect of the tooth tip improves the quenching hardness, but the high quenching temperature leads to martensitic coarser of the tooth back, which results in a significant decrease in the hardness. Moreover, with the increase in tempering temperature, the martensite in the microstructure of the tooth tip and tooth back was transformed into tempered trootensite and sortensite, and the primary and secondary carbides in the tooth tip became coarser, which led to the reduction of tempering hardness, and the fatigue properties changed too.
Mechanical property distribution of composites considering cured ply thickness variability
Authors: Ma Hongtu , Li Donghui 
Published: January 2024

Abstract
Variability is an essential feature of composites and directly affects the application of composite structures. Only a few studies have been conducted on the mechanical properties of composites considering cured ply thickness variability. This paper analyses the phenomena of cured ply thickness and the mechanical properties of materials obeying normal distribution after normalization. The distribution function and probability density function of the mechanical properties of composites considering the variability of cured ply thickness are derived. The correctness of the derived distributions is verified by Monte Carlo simulation, which compares the distribution of mechanical properties of composites after normalization with that considering the variability of cured ply thickness. The results showed that after considering the cured ply thickness variability, the mechanical properties showed a skewed distribution. At the lower percentile of the distribution, the mechanical properties are low compared to the normalized values, which reduces the permissible values of the composites.
Microstructural optimization of active element and reinforcement proportion of Si3N4/42CrMo joints
Authors: Wang Tianpeng , Sun Mingcheng , Cao Lin , Zhang Jie 
Published: January 2024

Abstract
Micron-TiN particles and Ti powder were introduced into the AgCu powder filler to design a particle-reinforced composite filler. This TiN particle (TiNp) modified brazing material was adopted to reliably braze Si3N4 ceramics onto 42CrMo steel. The ratio of active element Ti and TiNp reinforcement was optimized according to the joints’ microstructuret. The reaction layer’s thickness close to the Si3N4 increased by decreasing the TiNp content or increasing the Ti content according to the microstructural observation. In addition, higher Ti content would result in more Cu-Ti intermetallics precipitation in the joint and Ti2N could be detected instead of TiNp when 10 wt.% of Ti was used.
Primary columnar crystal growth characteristics affected by double stirrings in continuous casting square billet
Authors: Wu Chunlei , Wang Qiang , Sun Ye , Liu Xiaoming , Li Dewei , Shi Chunyang , Zhu Xiaowei , Zhao Lijia 
Published: January 2024

Abstract
The primary columnar crystal deviates due to forced flow induced by a mold electromagnetic stirrer (M-EMS). On this basis, the flow field can be qualitatively analyzed. As the growth characteristics of primary columnar crystal by double stirrings are still unknown, an electromagnetic swirling flow in the nozzle (EMSFN) approach was applied with M-EMS during a plant trial of continuous casting square billet. We first investigated the deflected angle of the primary columnar when using M-EMS or EMSFN solely. The deflected angle reduces gradually from the billet surface to the center when using only M-EMS. With increasing the EMSFN current, the deflected angles increase first, then reduce. When double stirrings with opposite directions are applied, the deflected angles fluctuate between positive and negative values near the billet surface. When the current is 600 A, the ratio of negative angles reaches 45%. This fluctuation of growth direction forms an interlaced dendrite structure, which restrains the solute migrating to the billet center.
Wildfires exacerbate inequalities in indoor pollution exposure
Authors: Krebs Benjamin , Neidell Matthew 
Published: January 2024

Abstract
Wildfires lead to dramatic increases in fine particulate matter pollution concentrations. Based on the premise that higher-income households purchase more defensive investments to reduce the degree to which outdoor pollution infiltrates indoors, in this study, we investigate how income contributes to outdoor–indoor pollution infiltration rates during wildfire events. Using crowd-sourced data from the PurpleAir Real-Time Air Quality Monitoring Network and econometric models that explore variations in monitor readings over time, we find increases in outdoor pollution lead to significant increases in indoor pollution, but disproportionately so in lower-income areas. The results highlight a new inequality in pollution exposure: not only are outdoor pollution levels higher for lower-income individuals, but indoor pollution levels are higher even for similar outdoor pollution levels.
Tetrahedron equation and quantum cluster algebras
Authors: Inoue Rei , Kuniba Atsuo , Terashima Yuji 
Published: January 2024

Abstract
We develop the quantum cluster algebra approach recently introduced by Sun and Yagi to investigate the tetrahedron equation, a three-dimensional generalization of the Yang-Baxter equation. In the case of square quiver, we devise a new realization of quantum Y-variables in terms q-Weyl algebras and obtain a solution that possesses three spectral parameters. It is expressed in various forms, comprising four products of quantum dilogarithms depending on the signs in decomposing the quantum mutations into the automorphism part and the monomial part. For a specific choice of them, our formula precisely reproduces Sergeev’s R matrix, which corresponds to a vertex formulation of the Zamolodchikov-Bazhanov-Baxter model when q is specialized to a root of unity.
Interface fluctuations associated with split Fermi seas
Authors: Walsh Harriet 
Published: January 2024

Abstract
We consider the asymptotic behaviour of a family of unidimensional lattice fermion models, which are in exact correspondence with certain probability laws on partitions and on unitary matrices. These models exhibit limit shapes, and in the case where the bulk of these shapes are described by analytic functions, the fluctuations around their interfaces have been shown to follow a universal Tracy–Widom distribution or its higher-order analogue. Non-differentiable bulk limit shape functions arise when a gap appears in some quantum numbers of the model, in other words when the Fermi sea is split. We show that split Fermi seas give rise to new interface fluctuations, governed by integer powers of universal distributions. This breakdown in universality is analogous to the behaviour of a random Hermitian matrix when the support of its limiting eigenvalue distribution has multiple cuts, with oscillations appearing in the limit of the two-point correlation function. We show that when the Fermi sea is split in the lattice fermion model, there are multiple cuts in the eigenvalue support of the corresponding unitary matrix model.
Comparison of TLS and SLAM technologies for 3D reconstruction of objects with different geometries
Authors: Szrek Aleksandra , Romańczukiewicz Kinga , Kujawa Paulina , Trybała Paweł 
Published: January 2024

Abstract
Technological advances have made the 3D mapping process easily available and simpler. However, there are still aspects that need to be improved and enhanced. The efficient acquisition of 3D data and reconstruction of objects with high accuracy continues to be a challenge for the scientific community. One of the most frequently used 3D mapping methods is Terrestrial Laser Scanning (TLS), which allows the collection of high-resolution and precise data. Another method gaining popularity among researchers and professionals is mobile scanning technology, which enables real-time data capture. Its mobility and speed make it an effective alternative to traditional scanning technologies. This article compares two mapping technologies: SLAM (Simultaneous Localization and Mapping) and TLS taking into account the technical aspects of the instruments, processing methods, time and cost, and concluding with an assessment of the final accuracy. The geometry of several selected objects was analyzed. The resulting root mean square error (RMSE) for the compared distances on the two point clouds was 5 cm, which proves that the SLAM technology can be successfully applied for scenarios requiring centimeter-level accuracy.