检索结果-内蒙古大学图书馆

Estimation of particle depth from two defocused images using the Fourier transform

Particuology 2020年第2期18卷 48-54页

作者： Wu Zhou Xu Luo Benting Chen Yukun Zhang Xiaoshu Cai School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093China

Depth from defocus is one technology for depth *** estimate particle depth information from two defocused images captured simultaneously by two coaxial cameras with different imaging *** images are processed with the Fourier transform to obtain the characteristic parameter(i.e.,the standard deviation of the relative blur kernel of these two defocused images).First,we theoretically analyze the functional relationship between the object depth and the standard deviation or variation of the relative blur ***,we verify the relationship *** analyze the influence of particle size,window size and image noise on the calibration curves using both numerical simulations and *** obtain the depth range and accuracy of this measurement system *** the verification experiments,we use a sample of glass microbeads and the irregularly-shaped dust particles on a microscope *** of these experiments present a suitable depth measurement ***,we apply the measuring system to the depth estimation of drops from a small anti-fogging *** results show that our system and image processing algorithm are robust for different types of particles,facilitating the in-line three-dimensional positioning of particles.

关键词： Depth from two defocused images Fourier transform Standard deviation of relative blur kernel Drops depth measurement Sensitivity and accuracy analysis

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Influence of Soil-Structure Interaction Models on the Dynamic Responses of An Offshore Wind Turbine Under Environmental Loads

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China Ocean engineering 2023年第2期37卷 218-231页

作者： TANG Hong-ming YUE Min-nan YAN Yang-tian LI Zhi-hao LI Chun NIU Kai-lun School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093China

Offshore wind turbines(OWTs) suffer wind, wave and earthquake loads. The investigation of OWTs' dynamic response under environmental loads is essential for structural safety assessment. The soil-structure interaction(SSI)significantly affects the responses of OWT under environmental loads. However, there is few systematic research about the difference in the dynamic response of different SSI models under environmental loads. In order to solve the problem, the OWT is modeled by shell element, and several SSI models are built. The wind, wave and earthquake loads are taken into account. Moreover, the dynamic response, fatigue and buckling analysis are performed by ANSYS. The results indicate that SSI cannot be ignored in the dynamic response of the OWT under wind and wave loads. The SSI can decrease the displacement response of the OWT by 19% under wind and wave loads and reduce the fatigue damage of the pile. Multi-layer SSI can strongly influence the OWT's dynamic response under wind and wave loads or earthquake-only load. The vertical earthquake load increases the dynamic response in three ***, in order to simulate real environment, multi-layer SSI, soil damping and vertical SSI must be considered to evaluate the displacement response of the OWT under wind, wave and earthquake loads. The earthquake and gravity loads can cause more obvious response of the OWT than that of only wind and wave loads. The top and bottom of the tower are prone to occur buckling.

关键词： OWT soil structure interaction earthquake dynamic analysis structural damage

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Investigation on the Transient Thermal Performance of a Mini-Channel Cold Plate for Battery Thermal Management

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Journal of Thermal Science 2021年第3期30卷 914-925页

作者： FANG Yidong SHEN Jiali ZHU Yue YE Fei LI Kang SU Lin School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093China

Cold plate is an important component for a liquid battery thermal management *** order to study the transient thermal performance of the cold plate under conditions with sharply increasing heat loads,the numerical model of a battery cold plate is *** validation experiment shows that the error between the simulation and experiment is around 2.5%to 5%.Effects of the coolant flow rate,the increase in heat flux,and the channel number are analyzed to study the transient thermal performance of the cold *** show that the average temperature of the cold plate at 540 s is lowered from 28.3℃ to 26.9℃ when the coolant flow rate is raised from 0.065 kg/s to 0.165 kg/*** temperature deviation is decreased when the coolant flow rate is increased from 0.065 kg/s to 0.115 kg/s;however,it is slightly increased if the coolant flow rate is further *** average temperature and temperature deviation are raised if the final heat flux is increased from11000 W/m^(2) to 16500 W/m^(2),which are 2 and 3 times of the initial,*** addition,increasing the channel number has slightly positive effect on the average temperature of the cold plate,while the temperature deviation is increased when the channel number is increased from 3 to 11 due to the non-uniform velocity distribution between each *** results of this study will be helpful during the design of cold plate for battery thermal management,especially for transient conditions with sudden rising heat loads like thermal runaway.

关键词： battery thermal management cold plate transient analysis temperature distribution mini-channel

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3D particle streak velocimetry by defocused imaging

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Particuology 2023年第1期72卷 1-9页

作者： Xiangrui Dong Xiaoxiao Wang Wu Zhou Fangting Wang Xinran Tang Xiaoshu Cai School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer for Power Engineering Shanghai 200093China

Particle streak velocimetry (PSV) has become one of the important branches of flow filed measurements. It extracts velocity information from particle trajectories captured by single frame long exposure images. Since the defocus of moving particle is inevitable during a long exposure time and under a large magnification, a novel three-dimensional (3D) velocity measurement method named defocusing particle streak velocimetry (DPSV) is proposed in this paper. On the one hand, an extension from two-dimensional (2D) to 3D velocity measurement with a monocular system is carried out. The depth information of the particle, which reflects the position in the third dimension, is indicated by the defocusing degree (characteristic parameter σ) of the particle images. The variation of σ along the trajectory is recognized by surface fitting of the gray value distribution of particle images, assuming that σ varies linearly along the trajectory. On the other hand, based on the linear fitting for the straight trajectory, an arc fitting model is developed for curved trajectories which are commonly captured in turbulent flow. The relationship between σ and the particle depth position z is experimentally calibrated using a LED light and a diaphragm. Finally, the DPSV method is verified in a submerged jet flow field as well as in a microchannel flow field to obtain the 3D velocity field with single monocular system.

关键词： Defocusing particle streak velocimetry Curve trajectory Three-dimensional velocity Gray value distribution

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Research on the Influence of Helical Strakes on Dynamic Response of Floating Wind Turbine Platform

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China Ocean engineering 2017年第2期31卷 131-140页

作者： DING Qin-wei LI Chun School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093 China

The stability of platform structure is the paramount guarantee of the safe operation of the offshore floating wind turbine. The NREL 5MW floating wind turbine is established based on the OC3-Hywind Spar Buoy platform with the supplement of helical strakes for the purpose to analyze the impact of helical strakes on the dynamic response of the floating wind turbine Spar platform. The dynamic response of floating wind turbine Spar platform under wind, wave and current loading from the impact of number, height and pitch ratio of the helical strakes is analysed by the radiation and diffraction theory, the finite element method and orthogonal design method. The result reveals that the helical strakes can effectively inhibit the dynamic response of the platform but enlarge the wave exciting force; the best parameter combination is two pieces of helical strakes with the height of 15%D （D is the diameter of the platform） and the pitch ratio of 5; the height of the helical strake and its pitch ratio have significant influence on pitch response.

关键词： floating wind turbine platform helical strakes orthogonal design

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Neural network-based interface reconstruction algorithm for two-phase fluid flow

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Fundamental Research 2025年

作者： Gong, Junhua Chen, Yujie Yu, Bo Sun, Dongliang Wang, Bohong Shi, Guoyun Chen, Bin State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China School of Mechanical Engineering Beijing Institute of Petrochemical Technology Beijing 102617 China School of Petroleum Engineering Yangtze University Wuhan 430100 China National & Local Joint Engineering Research Center of Harbor Oil & Gas Storage and Transportation Technology/Zhejiang Key Laboratory of Pollution Control for Port-Petrochemical Industry Zhejiang Ocean University Zhoushan 316022 China Kunlun Digital Intelligence Technology Company Beijing 102266 China

In two-phase fluid flow, the vapor-liquid interface tends to behave as a curved shape under the influence of surface tension. Curve reconstruction favors improving the resolution of bubbles or droplets in numerical studies. Based on artificial neural network (ANN) and convolutional neural network (CNN), two curve reconstruction algorithms, namely CIR-ANN and CIR-CNN, are proposed in this study. Both algorithms can achieve high-precision prediction of the center and radius when reconstructing interfaces using a portion of a standard circle, especially for the CIR-CNN algorithm. A strict mass conservation strategy is also proposed to ensure the reliability of the neural network predictions. In comparison with interface reconstruction algorithms such as piecewise linear interface construction (PLIC) algorithm, efficient least squares volume-of-fluid interface reconstruction algorithm (ELVIRA), quadratic spline based interface (QUASI) reconstruction algorithm after the first interface correction, Circle-based Interface Reconstruction (CIR), and CIR-ANN algorithm, the proposed CIR-CNN demonstrates good advantages in static interface reconstruction, with average accuracy ratios of 48.40, 86.69, 26.34, 4.07 and 2.26. However, when capturing the bubble under a complex rotation and shear recovery flow field, the advantage of the proposed algorithms decreases due to the increased complexity of the fluid volume fraction distributions. Regarding the computational time cost of reconstructing random circular interfaces, the proposed algorithms achieve average reduction ratios of 4.16, 7.86, and 34.14, respectively, compared to the CIR, ELVIRA, and QUASI algorithms. © 2025

关键词： ANN CNN Curve reconstruction Neural network Two-phase flow

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Implementation of an efficient segregated algorithm-IDEAL on 3D collocated grid system

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Chinese Science Bulletin 2009年第6期54卷 929-942页

作者： SUN DongLiang QU ZhiGuo HE YaLing Tao WenQuan State Key Laboratory of Multiphase Flow in Power Engineering School of Energy & Power Engineering Xi'an Jiaotong University Xi'an 710049 China

The segregated algorithm-IDEAL (inner doubly-iterative efficient algorithm for linked-equations) is an efficient and stable algorithm. In this algorithm, there exist inner doubly-iterative processes for pres-sure equation, which almost completely overcome two approximations in SIMPLE algorithm. Thus the coupling between velocity and pressure is fully guaranteed, greatly enhancing the convergence rate and stability of iteration process. In this paper, implementation of the IDEAL algorithm on a 3D collo-cated grid system is conducted. The interface velocity is calculated by the modified momentum inter-polation method (MMIM), by which the converged result is independent of the under-relaxation factor. Finally, five three-dimensional incompressible fluid flow and heat transfer problems are provided to compare the convergence rate and robustness between the IDEAL and three other most widely-used algorithms (SIMPLER, SIMPLEC and PISO). By the comparison it can be concluded that the IDEAL al-gorithm is more robust and efficient than the three other algorithms.

关键词：隔离算法网格系统理想 SIMPLE算法 3D 压力方程收敛速度迭代过程

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Dynamic Response of Offshore Wind Turbine on 3×3 Barge Array Floating Platform under Extreme Sea Conditions

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China Ocean engineering 2021年第2期35卷 186-200页

作者： LIU Qing-song MIAO Wei-pao YUE Min-nan LI Chun WANG Bo DING Qingwei School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093China

Offshore wind farm construction is nowadays state of the art in the wind power generation ***,deep water areas with huge amount of wind energy require innovative floating platforms to arrange and install wind turbines in order to harness wind energy and generate *** conventional floating offshore wind turbine system is typically in the state of force imbalance due to the unique sway characteristics caused by the unfixed foundation and the high center of gravity of the ***,a floating wind farm for 3×3 barge array platforms with shared mooring system is presented here to increase stability for floating *** NREL 5 MW wind turbine and ITI Energy barge reference model is taken as a basis for this ***,the unsteady aerodynamic load solution model of the floating wind turbine is established considering the tip loss,hub loss and dynamic stall correction based on the blade element momentum(BEM)*** second development of AQWA is realized by FORTRAN programming language,and aerodynamic-hydrodynamic-Mooring coupled dynamics model is established to realize the algorithm solution of the ***,the 6 degrees of freedom(DOF)dynamic response of single barge platform and barge array under extreme sea condition considering the coupling effect of wind and wave were observed and investigated in *** research results validate the feasibility of establishing barge array floating wind farm,and provide theoretical basis for further research on new floating wind farm.

关键词： Barge floating platform extreme sea conditions dynamic response stability

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Study on the self-diffusion coefficients of binary mixtures of supercritical water and H 2 , CO, CO 2 , CH 4 confined in carbon nanotubes

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Water Research 2025年 283卷 123856页

作者： Bowei Zhang Xiaoyu Li Jie Zhang Junying Wang Hui Jin State Key Laboratory of Multiphase Flow in Power Engineering (SKLMF) Xi’an Jiaotong University 28 Xianning West Road Xi’an 710049 Shaanxi PR China

Nano-confined binary mixtures are prevalent in the chemical industry, geology, and energy sectors. Investigating their mass transfer behavior can enhance process intensification. This study examines the confined self-diffusion coefficients of binary mixtures of supercritical water (SCW) with H 2 , CO, CO 2 and CH 4 in carbon nanotubes (CNT) using molecular dynamics (MD) simulations at temperatures of 673-973 K, a pressure of 25-28 MPa, solute molar concentrations of 0.01-0.3, and CNT diameters of 9.49-29.83 Å. We developed a novel machine learning (ML) clustering method to optimize abnormal MSD- t data, effectively extracting information and providing algorithmic enhancements for calculating the diffusion coefficient. We analyzed the effects of temperature, solute molar concentration, and CNT diameter on the confined self-diffusion coefficient and energy input. Results indicate that over 60 % of the solute energy input derives from the Lennard-Jones effect of the CNT wall. The confined self-diffusion coefficient of solutes increases linearly with temperature, saturates with increasing CNT diameter, and remains relatively constant with varying concentration. Finally, based on the unique relationship between CNTs and the confined self-diffusion coefficient, we developed a new mathematical model for prediction. The regression line exhibits an R 2 value of 0.9789, offering a new method for predicting the properties of nano-confined fluids.

关键词： Chemical industry

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Experimental analysis on adjusting performance of vapor-liquid two-phase flow controller

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Journal of Harbin Institute of Technology(New Series) 2006年第5期13卷 525-530页

作者：李慧君屠珊 School of Energy and Power Engineering North China Electric Power UniversityBaoding 071003ChinaState Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an 710049China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an 710049China

The vapor-liquid self-adjusting controller is an innovative automatic regulating *** order to ensure adjusted objects run safely and economically,the controller automatically adjusts the liquid flux to keep liquid level at a required level according to physical properties of vapor-liquid two-phase *** adjusting mechanics,the controller’s performance and influencing factors of its stability have been analyzed in this *** theoretical analysis and successful applications have demonstrated this controller can keep the liquid level steady with good *** actual application in industry has shown that the controller can satisfactorily meet the requirement of industrial production and has wide application areas.

关键词： vapor-liquid two-phase flow adjusting performance liquid level controller

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