bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase detection autofocus (PDAF) image sensor as applied to 3D imaging
Authors: Jutamulia Suganda 
Published: June 2022

Abstract
Auto-focus in a camera can be performed by comparing the image formed by light passing through a half of the imaging lens to the image formed by light passing through the other half of the imaging lens. A PDAF image sensor has an array of pixels. A microlens covers a pixel consisting of two photodiodes. In a camera using a PDAF image sensor, a photodiode receives light passing through a half of the imaging lens and the other photodiode receives light passing through the other half of the imaging lens. Thus, comparing light received by two photodiodes, a PDAF image sensor is capable of performing auto-focus of the camera. The PDAF image sensor is also capable of performing 3-D imaging.
Study on Rotating Stall of Multistage Compressor Using Wavelets
Authors: Wang Ziwei , Ma Shuai , Wang Jiantao , Li Bin , Cui Pengcheng 
Published: June 2022

Abstract
Rotating stall in the high speed compressor can lead to violent disruption of flow, damage to the blade structures and, eventually, engine shutdown. To investigate the mechanism of stall inception and stall propagation in multi-stage compressor, the onset and transient behavior of rotating stall in a transonic 2-stage compressor are simulated based on the in-house software ASPAC. Many sampling points are placed to monitor the flow variation. The analysis results of circumferential sampling points indicate that, the spectral characteristics of circumferential sampling points in steady state and unstable state are similar, the pressure pulsation is similar, but there exist phase difference. In the transition state, the main frequency is similar and the secondary frequency is slightly different, the 17th blade channel at the blade top of rotor 2 produces a disturbance with lower frequency and higher amplitude before other channels, which triggers the stall disturbance. The analysis results of axial sampling points show that the blade row interference frequency exists in the whole flow change process, and the disturbance of adjacent blade rows is dominant. The stall disturbance starts with rotor 2. This initial disturbance soon spreads to its adjacent stator 1 and stator 2. Rotor 1 is finally affected and enters into unstable state at about the 12th revolution.
Analysis of the aerodynamic characteristics of the outflow field of an SUV under the effect of side wind
Authors: Zhou Yang , Guan Qingyun , Xiao Ling , Yuan Xiayi 
Published: June 2022

Abstract
A domestic SUV model was selected, and two different side wind simulation methods of “partial car” and “partial wind” were analyzed to numerically simulate the flow field of SUV under different intensity of side wind, and the velocity-pressure distribution and aerodynamic force of the flow field under different side wind intensity were obtained. coefficients under different side wind strengths. The wind tunnel test was conducted at the same time, and the simulation results were compared and analyzed with the test results. The analysis results show that: the results of the two simulation methods are close to each other, and the trend is the same as that of the test, which is that the aerodynamic drag, lateral force and lift force gradually increase with the increase of the side yaw angle; considering the operation and difficulty of model building, the side wind simulation method is recommended to “deflect the wind”; the pressure maps of different parts of the body are analyzed to qualitatively The pressure maps of different parts of the body are analyzed to qualitatively explain the effect of side wind on the aerodynamic characteristics of SUV, which provides a reference for further research on the aerodynamic characteristics of SUV under the influence of side wind.
Flow Characteristic Study of High-speed Cavity Based on Detached-eddy Simulations
Authors: Zheng Yongqian , Zhang Jie , Li Huan , Wu Xiaojun , Jia Hongyin 
Published: June 2022

Abstract
The cavity is widely used in the advanced flight vehicle. However, there are also some new aerodynamic characteristic when cavity is exposed in high-speed flow. The flow characteristic of high-speed cavity is studied in this paper based on detached-eddy simulation method. The M219 cavity benchmark under transonic flow is used as the validation case for numerical methods and grid strategy. Comparison of predicted sound pressure levels and spectra against the wind tunnel experiment has proved that the numerical methods capture the major oscillation dynamics inside the cavity. The aerodynamic characteristic of cavity with a store is investigated in this paper, there are three vortexes in the cavity and the main vortex in the middle rotates around the store. The shear layer breaks earlier compared with clean cavity due to the turbulent flow around the store. However, the small store has little influence to the sound pressure level of cavity.
Study on the effect of inflow conditions on wind flow acceleration in mountainous micro-topography
Authors: Yin Yuan , Li Yangsen , Lin Ruizong , Liu Zhiwei , Fu Benzhao , Huang Guo , Zhang Hongjie 
Published: June 2022

Abstract
The acceleration of wind flow in mountainous areas can cause the destruction or collapse of transmission towers. The wind speed and direction of inflow have a significant impact on the flow acceleration in mountainous areas. The mountain terrain in the coastal area of Fujian was selected to study the influence of the inflow wind speed and direction on the acceleration effect. By analyzing the radar chart of the wind speed acceleration ratio of the monitoring points under 24 wind direction angles, the variation law of the wind speed acceleration ratio is consistent with the trend of the influence law obtained by the analysis of the surrounding terrain. The obtained simulation results are correct and credible, which can be used to correct the design wind speed of transmission lines in mountainous areas.
Application research on matching design of suspended AUV propeller based on CFD
Authors: Wu Pengxing , Liu Xianlong , Ling Zhengcheng , Chen Cheng 
Published: June 2022

Abstract
Combined with practical engineering application cases, this paper introduces a matching design method of suspended AUV propeller based on CFD. From theoretical design to practical engineering application, it is described from five aspects: demand analysis, design process, CFD simulation and experimental verification. The final results show that the designed propeller fully meets the application requirements, and this method is fully suitable for engineering practical application.
Research on Building Ventilation Condition and Numerical Simulation Based on Fluid Mechanics Model
Authors: Hao Huijuan 
Published: June 2022

Abstract
The article is based on the theory of computational fluid dynamics. We qualitatively analyse the difference between the total pressure on the windward side and the leeward side by numerical method, and compare and analyse the wind environment around the ground floor non-overhead courtyard building with the same width and height. The distribution of the velocity field, pressure field and trace map around the courtyard building with the ground floor fully overhead and the courtyard building with the ground floor not completely overhead are obtained. By introducing the CFD numerical simulation method, introducing finite element, Navier-Stokes equation, k-ε equation turbulence model, etc., combined with traditional ventilation design, the advantages of artificial ventilation and natural ventilation are integrated to obtain the optimal ventilation design scheme.
The axial fan design and commissioning test with nonuniform inlet flow
Authors: Qu Xiaoli , Ren Zebin , Yang Wenguo , Luo Yuanqiang 
Published: June 2022

Abstract
According to the two-dimensional flow theory of the axial fan rotor blades and the aerodynamic characteristics of the low speed wind tunnel, combined with the fan aerodynamic efficiency and wind tunnel pressure loss coefficient, a new equation which points out the inherent relationship of the fan blade setting angle, fan rotating speed and flow rate in wind tunnel circuit is derived. So a new method for fan rotor blade setting angle adjustment to satisfy the fan performance at off-design point by getting the test results of fan operating parameters but without the fan total pressure rise in the low speed wind tunnel is developed. Following the new method, the fan rotor blade setting angle adjusting value was provided directly only with the fan rotating speed and flow velocity in the wind tunnel test section, the adjusting target was achieved successfully by the new blade setting angle, the cost of the wind tunnel commissioning test were saved. The test results show that, after increasing the fan rotor blade setting angle by 4.5 degrees, when the flow velocity in the wind tunnel test section reaches 60m/s, the fan rotating speed is 570rpm, the deviation from the predicted fan rotating speed value of 575rpm is 0.9%. For the same test section flow velocity, the predicted value and the real value of the fan rotating speed are in good agreement, it proves that this method is reliable and accurate in practical application.
CFD-DEM based wind-deposited sand high concentration slurry pipe transport characteristics and erosion study
Authors: Wu Boqiang 
Published: June 2022

Abstract
In order to study the conveying process of wind-accumulated sand slurry pipeline, this study simulates the flow process of wind-accumulated sand slurry at 1m/s inlet flow rate with straight pipe bend and uphill by coupled CFD-DEM method. The fluid flow, particle motion and position distribution, pipe erosion and force during the whole process are analyzed based on the selection of a suitable traction model. The results show that the flow velocity of highly viscous slurry at the wall of the pipe is small which can easily lead to the deposition of sand particles, which is proved by the particle velocity cloud diagram. The extent of erosion and the degree of erosion increase with time, and the peak of erosion occurs at the bend. The force changes along the Y-direction in different parts of the pipe show that the extreme values of force and erosion are located at the bend. This part is the weak point of the whole pipeline slurry flow and erosion project should pay attention to reinforcement or monitoring.
Study on the flow around a cylinder by candle flame
Authors: Huang Junwei , Zhang Pengyu , Xie Zhuoxuan , Zhao Haojie , Xu Chenkun , Chi Jing , Lu Huiping 
Published: June 2022

Abstract
Interferometric measurement, schlieren method and shadow graph are commonly used to observe the low-speed steady flow. It is difficult to directly observe the flow direction in the experiment of flow around a cylinder at medium and high Reynolds number. On this premise, this paper mainly studies the relationship between the movement state of candle flame and the direction of candle airflow. This paper studies the influence of different wind speeds on the flow around a circular cylinder at medium and high Reynolds numbers. The innovation of this paper is to propose a new idea to directly observe the complex air flow, and to compare the candle flame state under different experimental conditions and the calculation images of different turbulence models.
Flow Field Analysis of Gas Injection and Brine Discharge in Natural Gas Storage Salt Cavern
Authors: Zhang Yi , Huang Wei , Cen Xueqi , Zhao Dandi , Chai Guoxing 
Published: June 2022

AbstractGas injection and brine discharge is the key link in the construction and safe operation of the salt cavern gas storage. Accurate description of the bottom flow field of the salt cavern in the process of gas injection and brine extraction is the basis and premise for determining the depth of the brine drainage string. According to the characteristics of gas injection and brine discharge, a numerical simulation calculation model of the brine flow field near the inlet of the brine discharge tubing was established. The brine flow field under different working conditions is simulated, and the safe brine drainage rate at different residual brine depths in the later stage of gas injection and brine drainage is determined, which provides technical support for the adjustment of gas injection brine drainage rate in the later stage of construction.
Rotordynamic characteristic of water lubricated plain journal bearing under transient load
Authors: Chen Pingwei , Wang Tong , Ma Wensheng , Chen Jie , Cao Rui 
Published: June 2022

Abstract
Transient startup operating parameter has a serious influence on the stability of water-lubricated bearings. In this study, CFD method was used to predict the rotordynamic coefficients of water lubricated bearings under transient loads. The stiffness and damping coefficients versus transient time for water-lubricated bearings are given. The stiffness and damping coefficients versus different transient loads for water-lubricated bearings are also given. The results show that the stiffness and damping coefficients will increase rapidly in a very short time. With the increase of impact time, both of them come to a steady value. With the increase of impact load, the direct stiffness and the direct damping coefficients of water lubricated bearing will increase. The value of cross-coupling stiffness and the cross-coupling damping coefficients will decrease.
Flow regulation and bottom hole pressure control under gas influx condition based on RMR system
Authors: Zhang Wenzhen , Zhang Jie , Wang Zhiheng , Sun Ruitao , Yu Sheng , Yang Zhijun 
Published: June 2022

Abstract
During the drilling process of RMR system, when the gas reservoir is drilled, the bottom hole pressure and formation pressure are in an unbalanced state, and the formation fluid invades the bottom hole under the action of pressure difference, further causing complex situation such as overflow and kick. In order to effectively control the bottom hole pressure during drilling and ensure drilling safety, a bottom hole pressure calculation model of RMR system under gas influx condition is established based on the gas-liquid two-phase flow theory. Three flow regulation methods of increasing the outlet flow of drilling pump and subsea pump at the same time, reducing the outlet flow of subsea pump while the outlet flow of drilling pump remains unchanged, and increasing the outlet flow of drilling pump while reducing the outlet flow of subsea pump are selected to dynamically simulate the change process of bottom hole pressure after flow regulation. Through data fitting, The relationship equation between them and bottom hole pressure is obtained, and the flow regulation method of RMR system when controlling bottom hole pressure under gas influx condition is formed.
Numerical simulation of saturated oil process based on digital pore model
Authors: Liu Haibo 
Published: June 2022

Abstract
In order to study the saturated oil process in the digital pore model, numerical simulations are performed by building a model. The results show that the direction of the capillary force is judged according to whether there is an odd or even number of fluid segments in the throat, and the odd segments cancel each other out, while the even segments have a capillary force; Three cases need to be considered when calculating the drag coefficient: (1) only single-phase fluid exists in the throat; (2) the corner of the throat is in the wetted phase, while the center of the throat is in the non-wetted phase; (3) the corner is in the wetted phase and the center of the throat is a multi-phase fluid. After performing saturated oil simulation calculations, the digital pore model can visualize the saturated oil process and results, which is realistic, fast, accurate and low cost, and is of great significance to the subsequent research on efficient reservoir development methods.
Uncertainty Quantification of Multivariate Correlated Output in the Simulation of Airfoil Flow
Authors: Zhang Chao , Chen Jiangtao , Zhao Wei , Wu Xiaojun 
Published: June 2022

Abstract
Due to the limitation of human cognition, there are uncertainties in the turbulence model closure coefficients that cannot be ignored. The key to assess model objectively is quantifying the uncertainty of model coefficients scientifically. In the CFD simulation of flow around the airfoil, wall pressure distribution is a multivariate correlated quantity. This paper developed a surrogate model method based on artificial neural network to characterize the mapping relationship between multivariate input and multivariate output. In order to reduce the output dimension and modelling difficulty, this paper use Proper Orthogonal Decomposition (POD) method. An RAE2822 benchmark case under transonic conditions is used to study the uncertainty of Spalart-Allmaras (SA) turbulence model coefficients and verify the method developed by this paper.
Optimal pacing strategy modeling of cycling individual time trials
Authors: Feng Jiafan , Liu Xiaowen , Deng Shaochun 
Published: June 2022

Abstract
Improving the performance of professional cyclists during individual time trials has been a challenge for several decades. In this study, the fatigue power profiles of male and female professional cyclists were characterized and a novel optimal pacing strategy model was established to determine the output power distribution based on the simulated annealing algorithm. Moreover, the model was implemented on the male 2021 UCI ITT course and the female 2021 Olympic ITT course. Compared with the actual performance of the professional cyclists, the race scores predicted by this model are among the best, which indicates that the model is highly practical and instructive. Considering riders are unlikely to follow the detailed plan exactly and their output power can deviate from the optimal power, a sensitivity analysis was conducted and the results demonstrated the high stability and reliability of the model.
The Relationship between Constructive Real Numbers and Left Number in Constructive Mathematics
Authors: Tang Jiamu , Wang Zhe , Wang Yunihan , Zhao Minxi 
Published: June 2022

Abstract
Generally, construction real numbers are considered constructive real numbers that coherently relate to some construction approaches. The analysis of this paper primarily focuses on the perspectives of left numbers in the study of constructive reviews. The review of this essay created a general connection between different concepts put together through the discovery and consideration of the available references. That was based on the assessment and introduction of these concepts based on the conditions and perspectives of constructive mathematics. The paper’s analysis also discussed and utilized specific propositions to prove and simplify the overall findings of this study. Further, the results indicate that the context of constructive mathematics has an existing algorithm available in any constructive number. Through this, constructive mathematics can produce a corresponding Left (L) number under the assumption that equivalent Left numbers can be the output with equivalent constructive real numbers (CRN). The findings of this analysis indicates that there is an existing algorithms that defines any constructive real number in the context of constructive mathematics. Through such correspondent relationship can generate a corresponding Left number. That is based on the assumption that in the context of equivalent real numbers, the possible output in this context is equivalent to Left number. Additionally, this assessment extensively utilized the Spector sequence while proving that the converse statement is false. We further suggest that the study can introduce more individuals to the basic concepts and applications of theories in the analysis.
Fuzzy Matching Model for Color Selection and Increasing Color Variety Based on Monte Carlo Simulation
Authors: Gao Jiefei , Zhu Guorui , Xin Yuankang , Wang Kunsheng , Fu Yingjie 
Published: June 2022

Abstract
Manufacturers of mosaic tiles often need to continuously improve the richness of their tile colors, adding one or several new colors to the existing several tile colors so that they can meet the needs of more users. In this thesis, this problem is discussed in terms of color fuzzy matching, combining Monte Carlo simulation and second-order diffusion decay model for mosaic tile color selection, and the addition of one or several new colors. The obtained results are visualized and displayed. This method of color enrichment can be applied to the construction industry, home improvement industry, and other industries to solve practical problems.
A model for the simulation of the Mars EDL process
Authors: Xu Miao , Xu Yiteng , Xiang Shiqi , Qiu Zheyong 
Published: June 2022

Abstract
In order to analyse the influence of the control operation during the soft landing on Mars and design the control operation, this paper designs a model to simulate the EDL process (i.e., entry, descent and landing) of the space probe, and uses the computer numerical simulation method to simulate. Its main advantage is that it can accurately analyse the impact on various control operations on the overall mission design, which can more intuitively to help aerospace personnel design control schemes for computer numerical simulation in actual engineering tasks. The detailed derivation process is given. The simulation results show the validity and practicability of the model.
Relationship Between the Evolution of Solar Magnetic Field and Flares in Different Active Regions
Authors: Tian Yunshuo 
Published: June 2022

Abstract
Two comparative active regions, NOAA AR 11283 and AR 11654 are studied. Both active regions have big sunspot numbers, and large areas. However, AR 11283 erupted two X-class flares, AR 11654 erupted little flares. Through investigating the evolution of magnetic field, the active region with complex magnetic configuration has more possibility to create big flares. NOAA is National Oceanic and Atmospheric Administration
Pulse Wave Signal Identification Method Based on EMD-CNN Model
Authors: Wang Hui , Pei Hongxing 
Published: June 2022

Abstract
in the research on the method of using pulse wave signal for identity recognition, this paper uses empirical mode decomposition (EMD) to decompose the pulse signal to obtain multiple intrinsic mode function (IMF) components distributed in different frequency bands. Each IMF component is screened and reconstructed with the correlation coefficient as the index, The IMF components used to reconstruct the pulse wave signal are identified by multi-channel parallel convolution neural network. In this paper, 30 healthy adults were identified, and the final recognition accuracy was 92.38%.
Wideband precision stabilization of the -18.6kV retarding voltage for the KATRIN spectrometer
Authors: Rodenbeck C. , Wüstling S. , Enomoto S. , Hartmann J. , Rest O. , Thümmler T. , Weinheimer C. 
Published: June 2022

Abstract
The Karlsruhe Tritium Neutrino Experiment (KATRIN) measures
the effective electron anti-neutrino mass with an unprecedented
design sensitivity of 0.2 eV (90 % C.L.). In this experiment, the
energy spectrum of beta electrons near the tritium decay endpoint is
analyzed with a highly accurate spectrometer. To reach the KATRIN
sensitivity target, the retarding voltage of this spectrometer must
be stable to the ppm (1 × 10-6) level and well known on
various time scales (μs up to months), for values around
-18.6 kV. A custom-designed high-voltage regulation system
mitigates the impact of interference sources in the absence of a
closed electric shield around the large spectrometer vessel. In this
article, we describe the regulation system and its integration into
the KATRIN setup. Independent monitoring methods demonstrate a
stability within 2 ppm, exceeding KATRIN's specifications.