bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical study on cavitation–vortex–noise correlation mechanism and dynamic mode decomposition of a hydrofoil
Authors: Yang Chen , Zhang Jinsong , Huang Zhenwei
Published: November 2022

The large eddy simulation model coupled with the modified Schnerr–Sauer cavitation model has been used to numerically simulate the unsteady cavitation and noncavitation flow of the three-dimensional NACA66 (National Advisory Committee for Aeronautics) hydrofoil under different operating conditions. The results show that the magnitude of the cavitation number plays a decisive role in the hydrofoil cavitation quasiperiodic phenomenon. The cavitation number of 1.25 is used as a typical working condition for analysis. Using the Ffowcs Williams–Hawkings acoustic analogy approach accompanied by the vorticity transport equation splitting, the growth and shedding of cavitation also lead to the growth and shedding of the vortex structure. The cavitation–vortex interaction is mainly influenced by the vortex stretching term and vortex dilatation term and amplitude of them are larger than 500. The baroclinic torque term may be responsible for generating vorticity during the cloud cavitation collapse and has a lower amplitude about 200. The cavity volume acceleration is the main influencing factor of the low-frequency pressure fluctuation around the cavitating hydrofoil. Moreover, the NACA66 hydrofoil surface-pressure data are collected for dynamic mode decomposition to locate the hydrofoil surface noise sources. The alternate high and low amplitude regions in the mode results overlap highly with the cavitation transformation regions. The cavity transformation and pressure fluctuations are the main reason for the generation of periodic low-frequency noise source regions on the hydrofoil surface. Moreover, the corresponding frequencies of each order mode are linearly correlated with the cavitation shedding frequency of 5.70 Hz. Combined with the results of the multiple mode comparisons, it can be inferred that the hydrofoil suction surface under the cavitation effect will generate quasiperiodic waves starting from upstream and moving downstream.
Corrigendum to: Direct action of leptin, obestatin and ginkgo on hormone release by luteinised human ovarian granulosa cells
Authors: Sirotkin Alexander V. , Tarko Adam , Fabova Zuzana , Mlyncek Miloš , Kotwica Jan , Alwasel Saleh , Harrath Abdel Halim
Published: November 2022

Context: The role of metabolic hormones, medicinal plants and their interrelationships in the control of human reproductive processes are poorly understood. Aims: To examine how leptin, obestatin and ginkgo (Ginkgo biloba L.) affect human ovarian hormone release. Methods: We analysed the influence of leptin and obestatin alone and in combination with ginkgo extract on cultured human ovarian granulosa cells. The release of progesterone (P), insulin-like growth factor I (IGF-I), oxytocin (OT) and prostaglandin F (PGF) were analysed by enzyme immunoassay and enzyme-linked immunosorbent assay. Key results: Leptin addition promoted the release of all the measured hormones. Obestatin stimulated the release of P, IGF-I and OT and inhibited PGF output. Ginkgo suppressed P, IGF-I and OT and promoted PGF release. Furthermore, ginkgo changed the stimulatory action of leptin on PGF to an inhibitory one. Conclusions: Leptin and obestatin are involved in the control of human ovarian hormone release and ginkgo influences their function. Implications: Leptin and obestatin could be useful as stimulators of human ovarian cell functions. The suppressive influence of ginkgo on ovarian function should lead to the development of ginkgo-containing drugs.
Strategies to reduce wildfire smoke in frequently impacted communities in south-western Oregon
Authors: Graw Richard L. , Anderson Bret A.
Published: November 2022

Background Efforts to mitigate the adverse effects of wildfire smoke have focused on modifying human behaviour to minimise individual exposure, largely accomplished by providing smoke forecasts, monitoring, and consistent public messaging. Aims To identify a strategy to reduce the amount of wildfire smoke in frequently impacted communities. Methods We identify frequent air pathways that transport smoke into five communities in south-western Oregon. We present a case study comparing the potential change in the 24-h average PM2.5 concentration between fuels burned during a wildfire which are and are not treated prior to the incident. Key results The concentration of PM2.5 would have decreased by 41% if fuel treatments occurred just prior to the wildfire. Of six vegetative strata, canopy, wood, and ground fuels contributed 88% of the total PM2.5 emissions, with shrub, herb, and lichen/litter/moss strata comprising the remaining 12%. Conclusions Fuel treatments can substantially reduce smoke emission from subsequent wildfires and if located in consideration of meteorological patterns, these fuel treatments can reduce ambient concentrations of PM2.5. Implications Fire and land managers can use the frequent air pathways and focus fuel treatments on the fuel beds and vegetative strata with the greatest potential to emit smoke during wildfires, to reduce the duration and concentration of wildfire smoke in frequently impacted communities.
Study of a low-frequency wireless charging system crossing the metal Dewar wall of a high-temperature superconducting magnet
Authors: Liu Guanjie , Gao Runqian , Tian Chenyu , Wang Danyang , Wu Yilong , Wang Yufei , Zhang Guomin
Published: November 2022

Using a wireless charging method to charge high-temperature superconducting (HTS) magnets is a way to solve the existing problem of high leakage heat introduced by charging through current leads. However, the available studies on charging HTS magnets using wireless charging methods rarely involve the role of a Dewar in the charging process. Nowadays, most HTS magnets use a metal Dewar because of the high requirements of the Dewar for gas tightness and mechanical strength. How to charge the HTS magnets wirelessly through the metal walls of the Dewar is an issue that needs to be addressed. In response to the above concerns, taking into account the role of the metal Dewar, a low-frequency wireless charging system with an isolation transformer as the core is proposed in this paper, where the primary coil of the transformer is a copper coil, installed on the outside of the Dewar. The secondary coil is a superconducting coil, installed on the inside of the Dewar. A theoretical model of the proposed wireless charging system is developed, and the prototype is fabricated based on the theoretical model. Both numerical and experimental methods were used to study the operational characteristics of the prototype, and the experimental results proved the validity of the theoretical model and the numerical model in this paper. Experimental results show that the proposed wireless charging system can charge an 8.5 mH HTS magnet with a current of 48.58 A over a 6 cm transmission distance, where the 6 cm gap includes a 1.6 mm thick metal wall. The results in this paper can provide new ideas for research work on charging HTS magnets wirelessly through a metal Dewar.
CosmicNet II: emulating extended cosmologies with efficient and accurate neural networks
Authors: Günther Sven , Lesgourgues Julien , Samaras Georgios , Schöneberg Nils , Stadtmann Florian , Fidler Christian , Torrado Jesús
Published: November 2022

In modern analysis pipelines, Einstein-Boltzmann Solvers (EBSs) are an invaluable tool for obtaining CMB and matter power spectra. To significantly accelerate the computation of these observables, the CosmicNet strategy is to replace the usual bottleneck of an EBS, which is the integration of a system of differential equations for linear cosmological perturbations, by trained neural networks. This strategy offers several advantages compared to the direct emulation of the final observables, including very small networks that are easy to train in high-dimensional parameter spaces, and which do not depend by construction on primordial spectrum parameters nor observation-related quantities such as selection functions. In this second CosmicNet paper, we present a more efficient set of networks that are already trained for extended cosmologies beyond ΛCDM, with massive neutrinos, extra relativistic degrees of freedom, spatial curvature, and dynamical dark energy. We publicly release a new branch of theclasscode, calledclassnet, which automatically uses networks within a region of trusted accuracy. We demonstrate the accuracy and performance ofclassnetby presenting several parameter inference runs from Planck, BAO and supernovae data, performed withclassnetand thecobayainference package. We have eliminated the perturbation module as a bottleneck of the EBS, with a speedup that is even more remarkable in extended cosmologies, where the usual approach would have been more expensive while the network's performance remains the same. We obtain a speedup factor of order 150 for the emulated perturbation module ofclass. For the whole code, this translates into an overall speedup factor of order 3 when computing CMB harmonic spectra (now dominated by the highly parallelizable and further optimizable line-of-sight integration), and of order 50 when computing matter power spectra (less than 0.1 seconds even in extended cosmologies).
Hybrid C8-BTBT/InGaAs nanowire heterojunction for artificial photosynaptic transistors
Authors: Nie Yiling , Xie Pengshan , Chen Xu , Jin Chenxing , Liu Wanrong , Shi Xiaofang , Xu Yunchao , Peng Yongyi , Ho Johnny C. , Sun Jia , Yang Junliang
Published: November 2022

The emergence of light-tunable synaptic transistors provides opportunities to break through the von Neumann bottleneck and enable neuromorphic computing. Herein, a multifunctional synaptic transistor is constructed by using 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) and indium gallium arsenide (InGaAs) nanowires (NWs) hybrid heterojunction thin film as the active layer. Under illumination, the Type-I C8-BTBT/InGaAs NWs heterojunction would make the dissociated photogenerated excitons more difficult to recombine. The persistent photoconductivity caused by charge trapping can then be used to mimic photosynaptic behaviors, including excitatory postsynaptic current, long/short-term memory and Pavlovian learning. Furthermore, a high classification accuracy of 89.72% can be achieved through the single-layer-perceptron hardware-based neural network built from C8-BTBT/InGaAs NWs synaptic transistors. Thus, this work could provide new insights into the fabrication of high-performance optoelectronic synaptic devices.
Four-channel CWDM transmitter chip based on thin-film lithium niobate platform
Authors: Chen Kaixuan , Chen Gengxin , Ruan Ziliang , Fan Xuancong , Zhang Junwei , Gan Ranfeng , Liu Jie , Dai Daoxin , Guo Changjian , Liu Liu
Published: November 2022

Multi-lane integrated transmitter chips are key components in future compact optical modules to realize high-speed optical interconnects. Thin-film lithium niobate (TFLN) photonics have emerged as a promising platform for achieving high-performance chip-scale optical systems. Combining a coarse wavelength-division multiplexing (CWDM) devices using fabrication-tolerant angled multimode interferometer structure and high-performance electro-optical modulators, we demonstrate monolithic on-chip four-channel CWDM transmitter on the TFLN platform for the first time. The four-channel CWDM transmitter enables high-speed transmissions of 100 Gb/s data rate per wavelength channel (i.e., an aggregated date rate of 400 Gb/s).
UME Kibble balance operating in air
Authors: Ahmedov Hacı , Orhan Recep , Korutlu Beste
Published: November 2022

The UME KB-3 operating since 2020 allows the realization of kilogram under ambient air conditions owing to its distinguishing design and operation protocol. This is possible only because the coil pair is stationary but the surrounding magnet assembly is moving. The mechanically decoupled nature of the magnet assembly allows the implementation of a local vacuum for displacement measurements rather than a vacuum covering the entire apparatus. The balance operates in single mode with simultaneous operation of weighing and moving phases instead of successive phases. A novel dynamical measurement procedure is developed in order to conform with the single phase measurements. The paper describes the apparatus and presents the measurement results for stainless steel mass artefact with a nominal value of 1 kg. The mass of the artefact is measured with a total relative uncertainty of 54 ppb.
Network meta-analysis: a statistical physics perspective
Authors: Davies Annabel L , Galla Tobias
Published: November 2022

Network meta-analysis (NMA) is a technique used in medical statistics to combine evidence from multiple medical trials. NMA defines an inference and information processing problem on a network of treatment options and trials connecting the treatments. We believe that statistical physics can offer useful ideas and tools for this area, including from the theory of complex networks, stochastic modelling and simulation techniques. The lack of a unique source that would allow physicists to learn about NMA effectively is a barrier to this. In this article we aim to present the ‘NMA problem’ and existing approaches to it coherently and in a language accessible to statistical physicists. We also summarise existing points of contact between statistical physics and NMA, and describe our ideas of how physics might make a difference for NMA in the future. The overall goal of the article is to attract physicists to this interesting, timely and worthwhile field of research.
Research on space construction and selection method of space-based information support equipment
Authors: Chang Qing , Liu Desheng , Yang Yang
Published: November 2022

With the rapid development of information technology and space technology, the important position of space-based information support equipment is increasingly prominent. However, the increasing types and quantities of space-based information support equipment also put forward higher requirements for the formulation of combat plans, decision-making and deployment of combat equipment. In this paper, based on the seven-step method, an ontology construction method suitable for space-based information support equipment is proposed, and the ontology construction tool Protégé is used to realize the ontology modeling of space-based information support equipment. By acquiring open source satellite data, the knowledge map construction tool Neo4j is used to construct the knowledge map of space-based information support equipment. Finally, the space-based information support equipment conforming to the combat mission can be obtained to provide assistance for the formulation of the combat plan and the decision of equipment utilization.
Study on the relationship between the length of mixing layer and the characteristic scale of mixing layer in multi-strut ejector
Authors: Zhou Letian , Xu Wanwu , Ye Wei
Published: November 2022

The flow structure of the multi-strut ejector based on jet segmentation has an obvious relationship with the transverse characteristic scale of the jet. Therefore, this paper studies the relationship between jet transverse characteristic size and mixing layer. Through the simulation of multi-strut ejectors with different number of struts, the development of mixing layer in the mixing process of jets with different transverse characteristic sizes is compared under the same boundary conditions. It is concluded that when there is no obvious coupling effect between the mixing layer and the shock & expansion wave, there is a linear relationship between the transverse characteristic scale of the jet and the mixing length of the flow direction, and the jet mixing with different transverse characteristic scales is consistent. When the shockwaves and expansion waves are strongly coupled with the mixing layer, the linear relationship between the jet transverse characteristic scale and the mixing layer length is not strong.
Noise simulation of wake field of solid rocket motor
Authors: Gao Yuhang , Zheng Jian
Published: November 2022

When the rocket engine works, it will produce high-temperature and high-speed gas, which will be rapidly mixed with the surrounding medium, and will produce huge jet noise. This paper studies jet flow field and sound field of rocket engine using Fluent. The broadband noise simulation shows that the noise distribution is related to the nozzle jet. The sound pressure data of transient FW-H observation points show that the noise frequency distribution is wide. At the same time, the size of the noise will increase with the increase of the inlet pressure, and the influence range will become larger with the increase of area expansion ratio.
Research on construction method of modular missile family general components based on self-organizing mapping
Authors: Guo Feiran , Yu Jianqiao
Published: November 2022

-As far as the missile family is concerned, the general components are an important part of the missile types in the missile family. At the same time, they are also a major advantage and feature of collaborative design of multiple missile types to form the missile family. In view of the poor universality of modules in traditional missile design, this paper proposes a general components construction method based on self-organizing mapping, which aggregates the components with similar structure and little difference in performance parameters as general components, so as to maximize the proportion of general components in the component library under the condition of meeting the performance index, and then improve the efficiency of missile equipment system while reducing the design cost.
Analysis of the influence of wave parameters on helicopter floating characteristics
Authors: Jiang Ting , Shi Sheng-zhe , Zheng Xiao-long
Published: November 2022

Foreign countries have accumulated rich experience in the research of helicopter floating characteristics. From the model test in the 1950s to the current numerical simulation and extrapolation evaluation, its technical maturity is significantly higher than that in domestic related fields. In order to fully study the influence of wave parameters on helicopter floating characteristics, sort out and refine the model test methods suitable for the study of helicopter floating characteristics, this paper takes a helicopter model as the research object, and carries out the research on the helicopter model test technology with emergency buoys, focusing on the influence range of wave parameters and wave direction on helicopter test results. The results show that the motion response of the helicopter under regular wave conditions presents typical periodic changes. When the helicopter encounters the influence of transverse wave, the rolling amplitude decreases with the increase of wavelength, and the acceleration amplitude of the nose and in the aircraft first increases and then decreases with the increase of wavelength; Under other wave direction conditions, the rolling angle, the acceleration amplitude of the nose and in the machine first increase and then decrease with the increase of the wavelength.
The Satellite Coverage Analysis is Based on a Combination of STK and MATLAB
Authors: Zhang Cheng , Wang Xuegang , Liu Yunzheng
Published: November 2022

In maritime military operations, reconnaissance satellites can provide all-around and efficient reconnaissance and surveillance of target areas in established orbits, regardless of territorial, airspace, and territorial sea restrictions, and are a beneficial means of leadership in today's military. STK can construct satellite motion models, and MATLAB can invoke the STK function module to achieve complex scene generation. The two are combined, respectively, with Walk Constellation grouping and single-satellite simulation of specific target areas at sea, resulting in coverage analysis reports with good results.
Mars Ascent Trajectory Optimization Based on Convex Optimization
Authors: Lan Yu , Li Ji
Published: November 2022

In this paper, a Mars ascent trajectory optimization algorithm based on convex optimization is designed for the Mars ascent trajectory optimization problem. The main accomplishment of this paper is the trajectory optimization of the second-stage ignition based on the convex optimization. For the first-stage ignition, open-loop guidance is used. In this stage, the ascender flies using the maximum thrust to track the attitude profile, thus completing the ascent flight control. In the presence of errors in the first-stage ignition, the experiment generates multiple sets of first-stage shutdown point data and completes simulation verification experiments based on them. The simulation verifies that the second-stage ignition trajectory optimization based on convex optimization algorithm can achieve high accuracy into orbit despite the large starting point deviation.
The dynamic model of the high-thrust orbital maneuvering engine with storable propellant
Authors: Su Qingdong , Wang Jinjin , Yan Mingxia , Sun Zhensheng , Zha Bailin , Huang Weifeng
Published: November 2022

The storable propellant rocket engine has the advantages of long-term storage and rapid use. A new design of a large-thrust orbital maneuvering engine is proposed for the first time and the dynamic model for working process is established by the multi-disciplinary dynamics simulation software AMEsim. The accurate model parameters of hydraulic and combustion components are obtained through actual unit tests. The dynamic characteristics of the engine are calculated and evaluated in detail, and the results show that the system has good robustness to disturbance parameters. The fluctuation of the propellant tank pressure has little influence on operating parameters. The peak pressure of the water hammer, especially at the tank outlet pipe, is about 17 times higher than the stable state. The starting sequence influences working conditions of the mixing ratio regulator and the thrust chamber for less than 0.1s, and has no influence on the stable working state of the engine. The research provides an effective method for designing a high-thrust orbital maneuvering engine system, which has broad prospects in low-Earth orbit transportation and military missions.
Structural Optimization of Single Crystal Turbine Blade Based on Recrystallization Critical Stress
Authors: Li Shifeng , Chen Suling , Ren Siyuan
Published: November 2022

In view of the problem that the surface structural recrystallization (SRR) is very easy to occur in the splitting gap area of the single crystal blade. A method to control the residual stress is proposed that based on the critical stress of single crystal recrystallization, and the structural details are optimized by combined with the numerical calculation and experimental verification. To reduce the residual stress level and change the residual stress distribution in the single crystal blade splitting gap. So as to control the level of residual stress, which is no more than the recrystallization critical stress. Finally, the experimental verification is completed by the optimized blade. The verification results show that the maximum residual stress is reduced by about 10% in the tail splitting region, and the recrystallization structure is completely eliminated in the original structure. It is proved that this method is a great effectiveness to control the structural integrity and surface structure connectivity of the single crystal blade.
Influence of brake-disc friction characteristics on anti-skid braking control system of aircraft
Authors: Du Xiaoqiong , Li Bin , Luo Linyin
Published: November 2022

The low-frequency landing gear walk of aircraft during braking processis studied. Firstly, by virtual of LMS Virtual.Lab motion software, the multi-body dynamic model of the landing gear is established, the motion pair and internal and external loads are applied, and the torsion spring is set at the connection between the landing gear and the fuselage to simulate the flexibility of the landing gear. Then, the variation of friction coefficient of brake discis considered in the model of braking pressure and torque. When the braking control system works, if the braking pressure is less than the limit value, the gear walk is less affected by the friction characteristics of the brake disc. If the braking pressure reaches the limit value, the law of gear walk is the same as that of the pilot's manual control of the braking pressure. At this time, the gear walk is only affected by the positive and negative slope of the friction coefficient of the brake disc. If the friction coefficient curve of the brake disc presents a negative slope, it may cause gear walk, and the greater the absolute value of the slope, the more obvious the gear walk is. Improving the friction characteristics of brake discs can provide a new strategy forgear walk control.
General compensation control method of flexible manipulator driven by tendon-sheath mechanism
Authors: Zhang Cunxiang
Published: November 2022

Flexible manipulator has been widely used because of its flexibility. In addition, the tendon-sheath mechanism has the advantages of compact structure and strong flexibility, and it can be used as the driving transmission mode of the flexible manipulator. However, the nonlinear and hysteretic characteristics of the tendon-sheath mechanism directly affect the motion accuracy of the manipulator. Firstly, the kinematic and static models of the flexible manipulator are analyzed considering the influence of multi section coupling. In addition, the mechanical transmission process of the tendon-sheath mechanism is analyzed. On this basis, a general feedforward compensation method for the flexible manipulator is established. The proposed model-based compensation control method can be applied to all flexible manipulators, and it is of great significance to promote the practical application of the manipulator.
Design and optimization of booster gliding model guided rocket scheme
Authors: Zhang Yifan , Zhao Meng , Tao Zhengxin , Mao Wabu , Luo Shijin , Bai Xibin , Peng Ke
Published: November 2022

In order to meet the needs of rocket innovation practice learning that takes into account both low-cost and high-level engineering practical training, the design of flight mission of the model guided rocket is proposed and the technical index analysis is carried out in the present study. The design of the rocket thrust system is completed using two paralleled YSR-32 motor, whose total engine impulse is 296.14𝑵 ∙ 𝒔; The mathematical model of the integrated aerodynamic / ballistic design optimization problem of rocket is constructed, adopting the aerodynamic configuration of side strip wing and x-shaped tail rudder and using Boost-Glide trajectory. Take the farthest range as the objective function, the influence of 8 variables on it is analyzed; By using Astrolab, a rapid overall design optimization platform of the rocket, the integrated simulation process of the aerodynamic / ballistic performance of the rocket is established; The maximum range of the optimization results is 1.29 𝒌𝒎, the takeoff mass is 2.8 𝒌𝒈, the speed at the shutdown point is 93.6 𝒎/𝒔, and the maximum flight time is 28.4s; The single use cost of the guided rocket is not exceed 1300 yuan.
Active vibration control of a piezoelectric composite laminate
Authors: Chen Hongxia , Liu Wenguang
Published: November 2022

An active vibration control method of the piezoelectric composite laminated plate under the external disturbance is studied. Firstly, the dynamic model of the piezoelectric composite laminated plate is derived based on the classical laminated plate theory and the Hamilton's principle. And subsequently, a sliding mode observer is developed for the external disturbance, and the stability of the observer is verified by the Lyapunov equation, and also the LQR controller is designed based on the observed state. The particle swarm algorithm is adapted to optimize the weighting matrix. In the end, the impacts of the geometric parameters and the stacking sequences on the dynamic behavior of the piezoelectric composite material plate is analyzed. Results indicate that the sliding mode observer can accurately track the original state, and the vibration of the piezoelectric composite material plate can be suppressed effectively by the LQR control based on the particle swarm
Dynamic Response Analysis of the Aircraft Exposed to the Lateral Travelling Gust
Authors: Jing Zhiwei , Tang Chu
Published: November 2022

The travelling gust from detonation is an interesting and severe excitation for a flying aircraft, and it is characterized by high emanating speed and takes strong energy. Previous investigations on the dynamic response characteristics of the aircraft in the tail-on or head-on travelling gust have been carried out. This paper focuses on the lateral travelling gust and its influence on the dynamic response of the aircraft. Based on conventional flight dynamics equations, the dynamics modelling and simulation technique of the rigid aircraft exposed to the lateral travelling gust is established. By employing the static pressure distributions, one quasi-steady aerodynamics computation method is presented to determine the aerodynamic force and moment on the aircraft in the travelling gust. Simulation results show that the approach presented in this paper is effective and can deal with the engineering requirement. Results also indicate that the enveloping process of the travelling gust increases the aerodynamic moment of the x-axis significantly and subsequently influences the dynamic responses along the x-axis.
Design and Analysis of the Wing Functioning as a Ramp for a Spitfire Flight Simulator
Authors: Zhang Yichong
Published: November 2022

This paper designed and analysed the wing for a Spitfire Mk9 Flight Simulator using three-dimensional modeling, finite element analysis and fatigue analysis methodologies with 3D EXPERIENCE, ABAQUS/FE-SAFE software. The results demonstrated that by using the wing structure as the access ramp to the cockpit simulator, the accessibility, safety and structural integrity could be improved vastly in comparison with the existing Spitfire flight simulators.
Advances in Resilience Engineering for Air Traffic Management Applications
Authors: Yi Jianmin , Ma Cunbao , Zhao Jin
Published: November 2022

As an emerging safety perspective, resilience engineering is attracting increasingly attentions in aerospace industry. Numerous researches have been carried out to explore ATM resilience properties from different aspects. Nevertheless, there appear to be significant variations on the research objects, issues concerned, methods employed and indexes used. As far as we know, there seems to be an absence of a dedicated literature review to explore the application status of resilience in ATM area. To this end, our work is concentrated on the research situation and progress of resilience in ATM. A wide range of databases are retrieved to obtain an extensive coverage of the literature. Subsequently, the research works are reviewed on the basis of different classifications followed by a brief introduction of related findings and implications. Attempting to provide some reference for further studies, promising directions are pointed out in view of the challenges and requirements. It is desired that this work may throw some light on further explorations of ATM resilience.
Simulation of Combustion Performance of High Salinity Organic Waste Liquid Incinerator
Authors: Li Wen-Kai , Qian yong-kang , Qian Xin-yu
Published: November 2022

High-salinity organic waste liquid is one of the important industrial pollution sources and the main by-product of petrochemical enterprises in China. Incineration is the mainstream technology for treating this kind of waste liquid. A three-dimensional numerical simulation of a practical 18t/h waste liquid incinerator was carried out using Fluent. The velocity, temperature, component concentration and particle trajectory distribution in the incinerator were obtained, proposing a corresponding incinerator performance optimization scheme according to the simulation results. The results demonstrate that the numerical combustion model established in this paper can accurately simulate the distribution of flow, combustion and heat transfer in the incinerator, verifying the reliability of the numerical model; The overall temperature and flow field organization of this type of waste liquid incinerator is relatively reasonable, with heat exchange reported only in the flue corner and some heat exchange surfaces. The flow field and temperature field distribution in the incinerator can be effectively modified so as to improve the boiler operation and maintenance cycle by optimizing the corner flow line and furnace structure.
Comparative study on the performance of turbulence models in flow separation of large expansion ratio nozzle
Authors: Wang Le , Tian Zhengyu , Yu Hang , Zhang Ye , Li Hua
Published: November 2022

The asymmetry of flow separation inside the nozzle with large expansion ratio is the main factor for the generation of side-load in the engine, so the accurate prediction of the flow separation is of great significance. The turbulence model is the key to the prediction, but in different scenarios, the performance of the turbulence model can introduce huge uncertainties. In this paper, a typical thrust-optimized nozzle (VOLVO-S1) is simulated and analyzed for three widely used turbulence models: SST

k - ω 、
RNG k - ε
and Spalart-Allmaras model. The results show that all these models can effectively predict the mode of shock separation phenomenon. The comprehensive performance of SST k - ω
is the best; The Spalart-Allmaras model has better prediction performance under low pressure ratio, and the RNG k - ε
model has better prediction effect under high pressure ratio.
Design of mini airborne emergency power supply based on super capacitor
Authors: Li Jian , Li Guoxing , Guo Yonglin
Published: November 2022

In order to solve the problem that it is difficult to install emergency battery with limited space on some flight planes, a micro emergency power supply based on super capacitor was designed in combination with the good energy storage characteristics of super capacitor. The selection calculation of capacitor and the design process of main control module and charge and discharge module are discussed in detail. In the laboratory environment, a small airborne test system was built to carry out verification experiments. The results show that the device meets the basic requirements of the system for backup power supply, and has the advantage of taking up less space and avoiding maintenance, which provides a new choice for the backup power supply selection of the future in-flight test system.
Overall design and sensitivity analysis of solar aircraft based on feasible region planning method
Authors: Zhang Liang , Ma Dongli , Yang Muqing , Yao Yuan
Published: November 2022

Solar aircraft has the ability of 24-hour uninterrupted cruise, so it has become a research hotspot all over the world. The existing overall design method of solar aircraft generally obtains the design scheme through the iterative operation of the balance equations. However, the overall parameters satisfying the boundary conditions are not unique, but distributed in a specific interval. This paper presents a method to construct the radial feasible region of the overall parameters based on the balance equations, and studies the sensitivity of the feasible region to the task indicators and performance indicators respectively, which provides suggestions for the optimization direction of the subsystem in the overall design stage. Finally, based on the above methods and research conclusions, the design scheme of a 15m wingspan solar aircraft is introduced. This paper provides an intuitive overall design method for solar aircraft, and offers scientific basis for multidisciplinary collaborative optimization.
Bearing capacity analysis of large deflection thin plate for civil aircraft
Authors: Zhang Kaiwen , He Zhouli , Huang Longhui
Published: November 2022

At present, the analysis of thin plate structure with small deflection and linear deformation is very mature, but the thin plate structure with large deflection and nonlinear deformation is often used in practical engineering design. Aiming at the thin plate structure with large deflection under out of plane load, this paper studies the bearing capacity of thin plate structure with large deflection under out of plane load by combining theoretical analysis, finite element simulation analysis and experimental analysis. According to the research, it is found that the process of theoretical analysis is complex and the workload and difficulty are too large. In practical engineering, some analysis results can be obtained quickly by using empirical formula and looking up the chart, but the application scope of these analysis results is small, and only the local stress results can be obtained. At present, designers usually use finite element simulation analysis to get the stress distribution of the whole structure. It should be noted that the geometric nonlinearity must be considered in the finite element analysis. The simulation results can provide a certain reference for engineering research and can be applied in practical engineering.
A New Design of the 3D Deployable Solar Array in the Aerospace Field and Kinematic Analysis during Deployment
Authors: Sun Jiayi
Published: November 2022

The paper focuses on a new design of the 3D deployable solar array for spacecraft and landers. Compared with existing solar array designs, the main advantage of this new design is the further increase in the area of the solar array. The principles of spatial rings and domes are used for this new design. This design consists of a large dome and four smaller rings. The model is constructed using Solidworks, and different configurations during the deployment are shown. The kinematic analysis shows that the length ratios of elements are independent of the input angle θ. It proves that this deployable structure has only one mobility. The configuration can be determined by a specific input angle. When the input angle θ increases, the top-view area of the structure increases, while the maximum height of the structure decreases. The volume of the increases and then decreases with the increasing θ. The maximum volume occurs at θ = 110°. In addition, the shape of the top-view geometry for a particular design is determined by two design parameters. It is found that the length ratios of elements increase with the increasing value of two design parameters.
Numerical simulation of jet atomization process of swirl nozzle
Authors: Gao Na , Zhang Xiaobin
Published: November 2022

As the initial conditions of evaporative combustion, the jet atomization formed by the swirl nozzle has the characteristics of large distribution space and small atomization particle size, which is very important for the study of the jet atomization of the swirl nozzle. In this paper, the cross-scale VTD model is used to comprehensively consider the actual situation of multi-scale and multi-phase flow coupling in the atomization process. The evolution process and the breaking shape of the rotating cone liquid film during the atomization and crushing process are studied. The results show that the complete broken shape formed by the rotating cone liquid film can be divided into three areas along the axial direction: continuous liquid film, primary crushing, and secondary crushing. Among them, the appearance of irregularly distributed small holes is a significant feature of primary crushing. The sign of secondary crushing is that the liquid filaments are broken into small-scale droplet particles; after the primary and secondary crushing, the fully developed cone-shaped liquid film will appear to move up the position of the primary crushing cavity and reduce the scope. At the same time, the initial position of the secondary crushing will move up.
Formation of H2CO and CH3OH in the Protoplanetary Disks
Authors: Xiao Lin , Liu Xia , Zhang Li
Published: November 2022

It is known that the complex organic molecules in planetary systems may be formed by the organic chemistry of gases and particles in protoplanetary disks. Among these molecules, H2CO and CH3OH are potential precursors of essential organic compounds like glycolaldehyde. We calculate the physical and chemical structures of the protoplanetary disks around LkCa 15 and MWC 480 stars, compare the obtained column densities with the observed values. Our results mostly show reasonable agreements with observations. We identify the formation of H2CO to be through the both gas-phase and dust surface reactions, while CH3OH is dominantly formed by surface chemistry in the original astrolabe and then released into the gas-phase by surface exothermic chemical reactions in the LkCa 15 disk. We studied the synthesis of complex organic molecules (NH2CHO and CH3OCHO) in the protoplanetary disk to predict the observable species and Molecular abundance. In the disks around LkCa 15 and MWC 480 stars, we suggest that the strong spectral line observation of NH2CHO belonging to band 4 may obtain good results with ALMA, the observation of CH3OCHO may be challenging.
According transformer parameters to design a high voltage power
Authors: Zhang Junling , Jin Renbo
Published: November 2022

When the load is empty pulse width modulation high frequency and high voltage power’ stabilization depth can easily cause oscillation, and when the full load of the voltage regulation is too shallow the voltage regulation effect is not good, the reason for this phenomenon is because the equivalent ratio and load correlation. The first thing you need to do is to find out why you can avoid the problem early in the design. To find out the cause, should to know the influence of the high voltage rectifier circuit on the total gain of the circuit and the dispersed parameters of the high frequency and high voltage transformer.
Dynamic load identification based on piecewise fitting trend term and smooth curve
Authors: Gao Wei , Ren Zhuoyu
Published: November 2022

wilson – θ back analysis method is a good load identification method. However, there are some problems, such as unsatisfactory load identification results caused by acceleration measurement errors. By deriving the recurrence formula of cumulative acceleration error of velocity and displacement, the different situations of displacement and velocity error are summarized. This paper introduces an algorithm for identifying the extreme points of trend items. The correction speed and displacement are modified by subsection fitting. The midpoint smoothing fitting of the load data after the initial identification is proposed which can better improve the accuracy of the load identification wilson – θ back analysis method. Finally, a simulation example shows that the displacement, velocity and the identified load error level are well controlled.
The Numerical Simulation of Cavitation Phenomenon in a Venturi Tube
Authors: Zhou Zibo , Li Qinglian , Liang Tao , Gong Shaotian
Published: November 2022

Venturi tubes are an important component of the liquid rocket engine to achieve extensive thrust regulation. On the basis of the existing venturi tube model, the relevant numerical simulation is carried out by the Mixture model and the k – ε turbulence model. Elaborated the typical cavitation flow field structure, cavitation area length and critical pressure ratio and analyzed the influence of outlet pressure on cavitation flow field in cavitation tubes. It was found that cavitation is always produced against the wall, and there is a core area of Cavitation. Cavitation in the core area is the most severe and the temperature is the lowest. From the core area outward, the gas phase area shows a patchy distribution, and there exists a gradient. Also, the critical pressure ratio that can produce cavitation is calculated. It is concluded that under the condition that cavitation can occur, the decrease of outlet pressure will lead to the lengthening of the cavitation area and the larger maximum temperature difference in the Venturi tube.
The principle and state-of-art applications of Hawking radiation
Authors: Guo Chunyu
Published: November 2022

Hawking radiation, firstly discovered in 1974 by Stephen Hawking, is a crucial quantum phenomenon, which proves that a black hole has been losing its mass since its formation. In this paper, the method of information retrieval and literature analysis are fully applied to introduce the principle and state-of-art applications of Hawking radiation. Three parameters used to describe the evaporation of black holes are analyzed. Furthermore, the tunnelling effect of entangled pairs near event horizon is described to explain Hawking radiation from a microscopic perspective. Then, the evaporating black holes are observed under wave optical conditions by the Fourier transformation of the spatial correlation function and detected in Laboratory condition by equivalenting entangled pairs to surface wave packets with sum-zero energy. Finally, a prediction is made that the widely used of extra-dimensional theory and high-energy particle technology as well as numerical researches in laboratory conditions will be strongly pushing the observation of Hawking radiation. Overall, these results shed light on further exploring the universe in terms of Hawking radiation.
Design of INS/GNSS Precise Posture Measurement and Positioning System for Complex System
Authors: Han Rong , Yang Jianfen , Tang Yumin , Yang Liben
Published: November 2022

In this paper, aiming at the robustness of the UAV control system and the accuracy of positioning and mapping in complex situations, the visual odometry is used as the front end of the positioning and mapping system, and the data of the IMU inertial sensor is fused on the basis of the monocular camera. The analysis completes the loosely coupled initialization process; the back-end constructs the cost function to realize the tightly coupled optimization, and uses the loop closure detection relocation and the four degree of freedom graph optimization to realize the nonlinear optimization. It is verified by simulation that the algorithm can improve the visual robustness in time when the UAV moves quickly or the scene has wrong results, so that the trajectory captured by the camera and the real-time construction map maintain global consistency, effectively eliminating the integral drift of the IMU, and correcting The noise of the IMU improves its positioning accuracy.
Habitability of Exoplanets around Black Hole
Authors: Hu Zhe , Jiang Qingyao , Li Miao
Published: November 2022

Contemporarily, investigation for habitability of exoplanets around black hole remains a hot topic. In this paper, the state-of-art experimental results relevant to the topic as well as the basic principles will be summarized. To be specific, basic information about black holes will be introduced first, including the 4 categories and detection method. Based on several observations for the effect of black hole towards near-by planets, this paper mainly focuses on the effect of black hole radiation and infrared echo on the habitability of exoplanets and the subsequent impact from radioactive power on biological features. These result shed light on guiding further study about relationship between exoplanets and black holes.
Experimental study on ignition and lean blowout characteristics of high temperature rise combustor
Authors: Luo Rui , Fu Yi , Jiang Jintao , Shi Pengyu , Liu Penghui , Wang Zhisheng , Fan Wei
Published: November 2022

Ignition and lean blowout characteristics are an important performance index of the Aeroengine combustor, which is directly related to the reliability of the whole engine. The ignition process of the combustor was filmed by a CCD camera, and three stages of successful ignition were obtained. By changing the intake conditions, the variation of the minimum ignition energy in the fuel-air ratio (FAR) is tested. With the decrease of the FAR, the minimum ignition energy increases and there is a sudden increase process. As the room temperature and pressure conditions, the lean blowout (LBO) FAR is roughly 0.014, and Increasing kerosene temperature can improve the LBO performance in the combustor.