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Blockage of the Deep-Sea Mining Pump Transporting Large Particles with Different Sphericity
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作者 TENG Shuang KANG Can +2 位作者 LI Ming-hui QIAO Jin-yu DING Ke-jin 《China Ocean Engineering》 SCIE EI CSCD 2023年第2期343-352,共10页
The present study aims to plumb blockage of the deep-sea mining pump transporting large particles with different shapes. A numerical work was performed through combining the computational fluid dynamics(CFD) technique... The present study aims to plumb blockage of the deep-sea mining pump transporting large particles with different shapes. A numerical work was performed through combining the computational fluid dynamics(CFD) technique and the discrete element method(DEM). Six particle shapes with sphericity ranging from 0.67 to 1.0 were selected. A velocity triangle is built with the absolute, relative, and circumferential velocities of particles. Velocity triangles with absolute velocity angles ranging from 90° to 180° prevail in the first-stage impeller. With declining sphericity, more particles follow the velocity triangle with absolute velocity angles ranging from 0° to 90°, which weakens the ability of particles to pass through the flow passage. Furthermore, the forces acting on the particles traveling in the impeller passage are analyzed. Large particles, especially non-spherical ones, suffer from high centrifugal force and therefore move along the suction surface of the impeller blades. Non-spherical particles undergo great drag force as a result of large surface area. The distribution of drag force angles is featured by two peaks, and one vanishes due to blockage.As particle sphericity declines, both magnitude and angle of the pressure gradient force decrease. Variation of the drag force and the pressure gradient force causes clockwise deflection of the centripetal force, resulting in deflection and elongation of particle trajectory, which increases the possibility of blockage. 展开更多
关键词 deep-sea mining pump particle sphericity velocity triangle force angle particle trajectory BLOCKAGE
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Microfluidic assisted 90%loading CL-20 spherical particles:Enhancing self-sustaining combustion performance 被引量:2
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作者 Ling-feng Yang Xian-rui Shi +2 位作者 Chun-zhi Li Bo Wu Chong-hua Pei 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第4期176-184,共9页
The performance of the chemical fuel determines the altitude,range and longevity of spacecraft in air and space exploration.Promising alternatives(e.g.,hypergolic ionic liquids or high-energy composites)with high-ener... The performance of the chemical fuel determines the altitude,range and longevity of spacecraft in air and space exploration.Promising alternatives(e.g.,hypergolic ionic liquids or high-energy composites)with high-energy density,heat of formation and fast initial rate are considered as potential chemical fuels.As the high-energy density material,hexanitrohexaazaisowurtzitane(CL-20)often serves as secondary explosive with poor self-propagating combustion behaviors.Herein,90%loading CL-20 microspheres with uniform particle sizes are precisely prepared by microfluid method,which exhibit unique hierarchical structure.The morphology,thermal behaviors,as well as combustion performance were further investigated.The results demonstrated that as-prepared spherical particles exhibit prominent thermal compatibility,and the enhanced self-sustaining combustion performance.This work provides an efficient method achieving the uniform high-energy density particles with excellent self-sustaining combustion performance. 展开更多
关键词 MICROFLUIDICS HEXANITROHEXAAZAISOWURTZITANE Spherical particles Thermal behavior Self-sustaining combustion
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Preparation of Spherical Tungsten Particles Assisted by Hydrothermal Method
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作者 GUO Jiawang WEN Xiaoqiang +2 位作者 WU Ying XU Jianbing ZHOU Jieying 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第6期1457-1462,共6页
We presented a strategy to prepare spherical tungsten powder by the combination of hydrothermal method and H2reduction process.In hydrothermal process,the micelle of tetraethylammonium bromide(TEAB)act as spherical te... We presented a strategy to prepare spherical tungsten powder by the combination of hydrothermal method and H2reduction process.In hydrothermal process,the micelle of tetraethylammonium bromide(TEAB)act as spherical templates for the deposition of tungsten oxide,whereas the excessive TEAB inhibit the formation of spherical tungsten oxide due to the dense molecular layer of TEAB on the tungsten oxide particles.Citric acid(CA)can control the formation rate and structure of the tungsten oxide when its concentration is more than 0.2 mol/L,because of its ability to coordinate with tungsten atoms.The synergistic effect of TEAB and CA facilitates the formation of spherical tungsten oxide with nanorod crown.After being treated by H_(2)at 600 and 650℃,the tungsten oxide particles are reduced to tungsten particles,which maintain the spherical structure of tungsten oxide and have porous structure. 展开更多
关键词 spherical tungsten particles spherical tungsten oxide hydrothermal method citric acid tetraethylammonium bromide
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A simple formula for predicting settling velocity of sediment particles 被引量:5
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作者 Song Zhiyao Wu Tingting +1 位作者 Xu Fumin Li Ruijie 《Water Science and Engineering》 EI CAS 2008年第1期37-43,共7页
Based on the general relationship described by Cheng between the drag coefficient and the Reynolds number of a particle, a new relationship between the Reynolds number and a dimensionless particle parameter is propose... Based on the general relationship described by Cheng between the drag coefficient and the Reynolds number of a particle, a new relationship between the Reynolds number and a dimensionless particle parameter is proposed. Using a trial-and-error procedure to minimize errors, the coefficients were determined and a formula was developed for predicting the settling velocity of natural sediment particles. This formula has higher prediction accuracy than other published formulas and it is applicable to all Reynolds numbers less than 2× 10^5. 展开更多
关键词 settling velocity spherical particle sediment particle sediment transport trial-and-errormethod
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Spherical YAG∶Ce^(3+) Phosphor Particles Prepared by Spray Pyrolysis 被引量:4
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作者 戚发鑫 王海波 朱宪忠 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第4期397-400,共4页
Spherical YAG:Ce^3+ phosphor particles with narrow size distribution were prepared by spray pyrolysis. The effects of the concentration of solution, the flow rate of cartier gas and the annexing temperature on the p... Spherical YAG:Ce^3+ phosphor particles with narrow size distribution were prepared by spray pyrolysis. The effects of the concentration of solution, the flow rate of cartier gas and the annexing temperature on the phosphor morphology were studied. The productivity of precursor particles shows a trend of drop after rising with the increase of concentration Raising the flow rate of nitrogen can improve the productivity of the precursor particles. Phosphor prepared by spray pyrolysis has obviously higher emission intensity than that synthesized by solid state reaction, spray pyrolysis makes Ce^3+ ions well distributed in the crystal lattice as the luminescent centers, and phosphor particles have regular sphericity and narrow size distribution. 展开更多
关键词 spray pyrolysis YAG white-LED spherical phosphor particles rare earths
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Effective Elastic Properties of 3-Phase Particle Reinforced Composites with Randomly Dispersed Elastic Spherical Particles of Different Sizes Dedicated to Professor Karl Stark Pister for his 95th birthday 被引量:1
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作者 Yu-Fu Ko Jiann-Wen Woody Ju 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第12期1305-1328,共24页
Higher-order multiscale structures are proposed to predict the effective elastic properties of 3-phase particle reinforced composites by considering the probabilistic spherical particles spatial distribution,the parti... Higher-order multiscale structures are proposed to predict the effective elastic properties of 3-phase particle reinforced composites by considering the probabilistic spherical particles spatial distribution,the particle interactions,and utilizing homogenization with ensemble volume average approach.The matrix material,spherical particles with radius a1,and spherical particles with radius a2,are denoted as the 0th phase,the 1st phase,and the 2nd phase,respectively.Particularly,the two inhomogeneity phases are different particle sizes and the same elastic material properties.Improved higher-order(in ratio of spherical particle sizes to the distance between the centers of spherical particles)bounds on effective elastic properties of 3-phase particle reinforced proposed Formulation II and Formulation I derive composites.As a special case,i.e.,particle size of the 1st phase is the same as that of the 2nd phase,the proposed formulations reduce to 2-phase formulas.Our theoretical predictions demonstrate excellent agreement with selected experimental data.In addition,several numerical examples are presented to demonstrate the competence of the proposed frameworks. 展开更多
关键词 particle reinforced composites MICROMECHANICS spherical particle interactions ensemble volume average HOMOGENIZATION probabilistic spatial distribution higher-order bounds multiscale
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Calculation of terminal velocity in transitional flow for spherical particle
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作者 Zhang Lei Honaker Ricky +2 位作者 Liu Wenli Men Dongpo Chen Jinxiang 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第2期311-317,共7页
The terminal velocity has been widely used in extensive fields, but the complexity of drag coefficient expression leads to the calculation of terminal velocity in transitional flow (1 〈 Re ≤ 1000) with much more d... The terminal velocity has been widely used in extensive fields, but the complexity of drag coefficient expression leads to the calculation of terminal velocity in transitional flow (1 〈 Re ≤ 1000) with much more difficulty than those in laminar flow (Re ≤ 1) and turbulent flow (Re ≥ 1000). This paper summarized and compared 24 drag coefficient correlations, and developed an expression for calculating the terminal velocity in transitional flow, and also analyzed the effects of particle density and size, fluid density and viscosity on terminal velocity. The results show that 19 of 24 previously published correlations for drag coefficient have good prediction performance and can be used for calculating the terminal velocity in the entire transitional flow with higher accuracy. Adapting two dimensionless parameters (w*, d*), a proposed explicit correlation, w*=-25.68654 × exp (-d*/77.02069)+ 24.89826, is attained in transitional flow with good performance, which is helpful in calculating the terminal velocity. 展开更多
关键词 Transitional flow Drag coefficient Terminal velocity Spherical particle Calculation
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THE MOTION OF A SPHERICAL PARTICLE IN THE STOKES FLOW OUTSIDE A CIRCULAR ORIFICE
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作者 山慧贤 严宗毅 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第9期829-841,共13页
For any study ofa suspension entering a pore, the knowledge of the force and moment exerted on a solute particle in an arbitrary position outside the pore is essential, 'This paper for the first lime presents appr... For any study ofa suspension entering a pore, the knowledge of the force and moment exerted on a solute particle in an arbitrary position outside the pore is essential, 'This paper for the first lime presents approximate analytical expressions (in closed form) of all the twelve force and moment coefficienis for a sphere outsied a circular orifice, on the basis of a number of discrete data computed by Yan et al(1987).These coefficients are then applied to calculate the trajectory and angular velocity of a spherical particle approaching the pore at zero Reynolds number. The trajectory is in excellent agreement with the available experimental results. An analysis of the relative importance of the coefficients shows that the rotation effect cannot be neglected near the pore opening or near the wall, and that the lateral force effect must be taken into account in the neighborhood of the edge of the pore opening. It is due to neglecting these factors that previous theoretical results deviate from the experimental ones near the pore opening. The effects of the ratio of the particle to pore radii as well as the influences of the graritytbuoyance on the particle trajectory, velocity distribution and rotation are discnssed in detail. It is pointed out that in the experiments of neutrally-buoyant suspensions, the restriction on the density of the particle is most demanding for a large particle size.The expressions of forces and moments presenled herein are complete, relatively accurate and convenient, thus providing a good prerequisite for further studies of any problems involving the entrance of particles to a pare. 展开更多
关键词 THE MOTION OF A SPHERICAL particle IN THE STOKES FLOW OUTSIDE A CIRCULAR ORIFICE
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THE EFFECTIVE MODULI OF COMPOSITE REINFORCED BY SPHERICALCOATING PARTICLES
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作者 卢子兴 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第10期997-999,0-0+0-0+0-0,共10页
The effective moduli of composite reinforced by spherical coating particles are investigated by the four phase spheroidal model and the theory of equivalent media. The theoretical predicting formulae of bulk modulus a... The effective moduli of composite reinforced by spherical coating particles are investigated by the four phase spheroidal model and the theory of equivalent media. The theoretical predicting formulae of bulk modulus and shear modulus have been derived for this kind of composite in this paper. These formulae can reduce to the results of three phase spheroidal model which had been obtained by others for composite reinforced by particles. 展开更多
关键词 spherical coating particles COMPOSITE effective modulus
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Experimental study on influence of blade angle and particle size on particle mechanics on a batch-operated single floor of a multiple hearth furnace 被引量:1
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作者 Max Kriegeskorte Nikoline Hilse +1 位作者 Phil Spatz Viktor Scherer 《Particuology》 SCIE EI CAS CSCD 2024年第2期224-240,共17页
In industry,multiple hearth furnaces are used for the thermal treatment of particulate material.The current contribution concentrates on the experimental analysis of particle mechanics for a batch-operated single floo... In industry,multiple hearth furnaces are used for the thermal treatment of particulate material.The current contribution concentrates on the experimental analysis of particle mechanics for a batch-operated single floor of a multiple hearth furnace.The particles are agitated on the circular floor by a single,rotating rabble arm equipped with three flat rabble blades of 10 mm thickness.The blade angle,defined as the angle,which the blade is inclined against the tangential direction,is varied from 0°to 90°.A single layer of spherical polyoxymethylene(POM)particles with three different diameters(5,10 and 20 mm)is placed on the floor.To analyze the results,two parameters have been extracted from image analysis when the bed of particles is agitated,first,the area not covered by particles and second,the frequency distribution of the mean distance among the particles.The particle free surface area increases with the inclination of the blades.The evolution of the particle free surface area differs for the different particle diameters.In general,the maximum particle free area for all blade angles is the largest for the 5 mm particles followed by the 20 mm particles.For the 10 mm particles,the particle free surface area starts for a blade angle of 0°at larger values than for the 20 mm particles but the values fall below the values for the 20 mm particles for larger blade angles.The reason for this behavior is discussed in detail.The mean distance among the particles is a parameter characterizing the length scales dominating the effects on the floor.The frequency distribution of the mean distance among particles provides infor-mation about the morphology of the particle bulk,for example,whether the free surface area is inter-spersed with particles. 展开更多
关键词 Hearth furnace floor particle movement Spherical particles particle free surface area Mean distance among particles
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Ray tracing particle image velocimetry-Challenges in the application to a packed bed 被引量:1
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作者 Christin Velten Mirko Ebert +1 位作者 Christian Lessig Katharina Zahringer 《Particuology》 SCIE EI CAS CSCD 2024年第1期194-208,共15页
Ray tracing Particle Image Velocimetry(RT-PIV)is an optical technique for high resolution velocity measurements in challenging optical systems,such as transparent packed beds,that uses ray tracing to correct for disto... Ray tracing Particle Image Velocimetry(RT-PIV)is an optical technique for high resolution velocity measurements in challenging optical systems,such as transparent packed beds,that uses ray tracing to correct for distortions introduced by transparent geometries in the light paths.The ray tracing based correction is a post processing step applied to the raw PIV particle images before classical PIV evaluation.In this study,RT-PIV is performed in the top layer of a body centred cubic(bcc)sphere packing with gaseous flow,where optical access is obtained by the use of transparent N-BK7 glass balls with a diameter of d=40 mm.RT-PIV introduces new experimental and numerical challenges,for example a limited field of view,illumination difficulties,a very large required depth of field and high sensitivity to geometric parameters used in the ray tracing correction.These challenges and their implications are the main scope and discussed in the present work.Further,the validation of the ray tracing reconstruction step is presented and examples for the obtained corrected vector fields in a packed bed are given.The results show the strength of the method in reconstructing velocity fields behind transparent spheres that would not have been accessible by optical measurement techniques without the ray tracing correction. 展开更多
关键词 Ray tracing particle image velocimetry(RT-PIV) Transparent spherical particles Packed bed Distortion correction Gas flow
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Particle morphology control for spherical powder fabrication using the ball milling process with DEM simulation
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作者 Battsetseg Jargalsaikhan Khulan Uranchimeg +2 位作者 Amgalan Bor Kyung Sung Kim Heekyu Choi 《Particuology》 SCIE EI CAS CSCD 2024年第7期41-50,共10页
Characteristics of spherical particles on copper powder and changing sizes were studied in a ball mill under various experimental conditions,such as different ball diameters,high rotation speeds,and milling times,usin... Characteristics of spherical particles on copper powder and changing sizes were studied in a ball mill under various experimental conditions,such as different ball diameters,high rotation speeds,and milling times,using a discrete element method(DEM)simulation.This experiment has investigated the characteristics of spherical particle morphology evolution involved in the mechanical alloying of copper powder.The morphological evolution of the copper particle was analyzed using scanning electron microscopy(SEM).A spherical copper particle was shown with a roundness value using imageJ software.The DEM was used to simulate the ball motion in a planetary ball mill,and the impact energy and shear energy generated during the collision were analyzed to estimate the contact number between the ball and the ball wall.Therefore,as the size of the ball decreased,the number of ball-to-ball and ball-to-wall contacts increased accordingly,and the spherical shape of the copper powder changed. 展开更多
关键词 Planetary ball mill DEM simulation Spherical particle morphology Copper powder Ball diameter
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Effect of Mg-based spherical quasicrystal on microstructures and mechanical properties of ZA54 alloy 被引量:6
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作者 张金山 张永青 +3 位作者 张焱 许春香 王晓明 严杰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第7期1199-1204,共6页
To improve the strength, toughness and heat-resistance of magnesium alloy, the microstrucmre and mechanical properties of ZA54 alloy reinforced by icosahedral quasicrystal phase (/-phase) particles were studied. Exc... To improve the strength, toughness and heat-resistance of magnesium alloy, the microstrucmre and mechanical properties of ZA54 alloy reinforced by icosahedral quasicrystal phase (/-phase) particles were studied. Except α-Mg, φ-phase and τ-phase, MgZnYMn I-phase particles can be obtained in ZA54-based composites by the addition of icosahedral quasicrystal-contained Mg-Zn-Y-Mn master alloy. The introduction of MgZnYMn I-phase into ZA54 alloy has great contribution to the refinement of matrix microstructures and the improvement of mechanical properties. When the addition of Mg-based spherical quasicrystal master alloy is up to 3.5% (mass fraction), the macro-hardness of ZA54-based composites is increased to HB 68. The impact toughness of composites reaches the peak value of 18.3 J/cm^2, which is about 29% higher than that of ZA54 mother alloy. The highest tensile properties at ambient and elevated temperatures with master alloy addition of 2.5% (473 K) are also obtained in ZA54-based composites with 3.5% (mass fraction) Mg-Zn-Y-Mn master alloy addition. The ultimate tensile strength of composites at ambient and elevated temperatures are 192.5 MPa and 174 MPa, which are 23.4% and 33.8% higher than that of ZA54 mother alloy, respectively. The improved mechanical properties are mainly attributed to the pinning effect of I-phase on grain boundaries. 展开更多
关键词 magnesium alloy spherical quasicrystal particles ZA54 alloy composite strengthening heat-resistance ~: magnesium alloy spherical quasicrystal particles ZA54 alloy composite strengthening HEAT-RESISTANCE
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High Cr(Ⅵ) adsorption capacity of rutile titania prepared by hydrolysis of TiCl4 with AlCl3 addition 被引量:2
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作者 Shun Wu Xiao-bo He +1 位作者 Li-jun Wang Kuo-Chih Chou 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第8期1157-1163,共7页
Rutile titania(TiO2)was successfully prepared via hydrolysis of TiCl4 in the presence of AlCl3.The powders were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),and Brunauer-Emmett-Tell... Rutile titania(TiO2)was successfully prepared via hydrolysis of TiCl4 in the presence of AlCl3.The powders were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),and Brunauer-Emmett-Teller(BET)surface area analysis.In the present system,AlCl3 functions as a nucleating agent and induces the formation of rutile TiO2.The influences of HCl and isopropanol concentrations on the purity and morphology of the rutile TiO2 were investigated.The purity of the rutile TiO2 increased with increasing concentration of HCl.Evenly dispersed rutile TiO2 particles with a spherical morphology were obtained when the HCl and isopropanol concentrations were 0.5 and 1 mol·L-1,respectively.Furthermore,the prepared TiO2 powders were used in adsorption tests of the heavy metal pollutant Cr(Ⅵ).Rutile TiO2 sample S-9 demonstrated greater adsorption performance and a removal efficiency that was greater than 99.95%after60 min of adsorption when the Cr(Ⅵ)concentration was 200 mg·L-1.The maximum adsorption capacity on rutile TiO2 was 28.9 mg·g-1.This work provides an easy path to prepare a high-performance rutile TiO2 adsorbent with potential applications in water pollution treatment. 展开更多
关键词 rutile titania HYDROLYSIS spherical particles adsorption
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Surface deformation under overlapping impacts of solid particles 被引量:1
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作者 Xuerui ZANG Xuewen CAO +3 位作者 Zhenqiang XIE Jun ZHANG Farzin DARIHAKI Yang LIU 《Friction》 SCIE EI CAS CSCD 2023年第2期280-301,共22页
To improve the accuracy of erosion prediction,the effect of subsequent particles impacting the same area while the first single particle rebounds from the substrate must be considered.This issue has rarely been consid... To improve the accuracy of erosion prediction,the effect of subsequent particles impacting the same area while the first single particle rebounds from the substrate must be considered.This issue has rarely been considered in studies pertaining to erosion damage.In the present study,the ABAQUS software is used to investigate the erosion crater morphology and stress distribution on a target material subjected to overlapping impacts of spherical particles.Subsequently,the validated model is applied to investigate the effect of the overlapping impacts of particles on the target.Accordingly,the correlation between erosion severity and the impact locations of the two incident particles is quantified.The results show that the horizontal distance between two solid particle impact locations can significantly affect the erosion magnitude and pattern.The interactions of the resulting craters diminish when the horizontal distance exceeds 0.6 times the particle diameter.When the horizontal distance is approximately 0.06 times the particle diameter,the energy loss originating from collisions reaches the maximum,which modifies the crater morphology.The present study is expected to provide in-depth insights into erosion mechanisms and erosion modeling. 展开更多
关键词 overlapping impact spherical particle surface morphology energy dissipation ABAQUS simulation
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Standard Model Masses Explained
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作者 T. R. Mongan 《Journal of Modern Physics》 2021年第7期983-987,共5页
The Standard Model of particle physics requires nine lepton and quark masses as inputs, but does not incorporate neutrino masses required by neutrino oscillation observations. This analysis addresses these problems, e... The Standard Model of particle physics requires nine lepton and quark masses as inputs, but does not incorporate neutrino masses required by neutrino oscillation observations. This analysis addresses these problems, explaining Standard Model particle masses by describing fundamental particles as solutions of Einstein’s equations, with radii 1/4 their Compton wavelength and half of any charge on rotating particles located on the surface at each end of the axis of rotation. The analysis relates quark and lepton masses to electron charge and mass, and identifies neutrino masses consistent with neutrino oscillation observations. 展开更多
关键词 Standard Model Masses Spherical Fundamental particles Einstein’s Equations
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Combustion characteristics of low-quality lignite for different bed material sphericities in a circulating fluidized bed boiler:A numerical study
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作者 Barış Gürel Gülşah Karaca Dolgun +1 位作者 Osman İpek Ali Keçebaş 《Particuology》 SCIE EI CAS CSCD 2024年第7期364-382,共19页
This study delves into the combustion behavior of various lignite types within a circulating fluidized bed boiler(CFBB),with a primary focus on the impact of different bed material sphericity ratios(0.5,0.7,and 0.9).U... This study delves into the combustion behavior of various lignite types within a circulating fluidized bed boiler(CFBB),with a primary focus on the impact of different bed material sphericity ratios(0.5,0.7,and 0.9).Utilizing bed material with a sphericity ratio of 0.9 sourced from theÇan power plant and verified through experimentation,the research reveals several key findings.Notably,furnace temperatures tended to rise with higher sphericity ratios,albeit with variations between lignite types,particularly highlighting the complexity of this relationship in the case of GLI-Tunçbilek lignite.Pressure levels in the combustion chamber remained consistent across different sphericity ratios,indicating minimal influence on pressure dynamics.Improved combustion efficiency,especially at the bottom of the boiler,was observed at lower sphericity levels(0.5 and 0.7)forÇan lignite,as reflected in CO_(2) mole fractions.While NO_(x) emissions generally decreased with lower sphericity,the sensitivity to sphericity varied by lignite type,with Ilgın lignite showcasing low NO_(x) but high SO_(2) emissions,underscoring the intricate interplay between lignite properties,sphericity,and emissions.Overall,this study advances our understanding of CFBB combustion dynamics,offering insights valuable for optimizing performance and emissions control,particularly in lignite-based power. 展开更多
关键词 Circulating fluidized bed boiler Computational particle fluid dynamics method particle sphericity ratios NO_(x)and SO_(2)emissions Energy production efficiency
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Settling behavior of spherical particles in vertical annulus:Experimental study and model development 被引量:3
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作者 Zhaopeng Zhu Mengmeng Zhou +5 位作者 Xianzhi Song Shuo Zhu Gensheng Li Zhengming Xu Xuezhe Yao Buwen Yu 《Particuology》 SCIE EI CAS CSCD 2022年第9期114-123,共10页
Coiled tubing(CT)drilling technology offers significant advantages in terms of cost and efficiency for exploitations of unconventional oil and gas resources.However,the development of CT drilling technol-ogy is restri... Coiled tubing(CT)drilling technology offers significant advantages in terms of cost and efficiency for exploitations of unconventional oil and gas resources.However,the development of CT drilling technol-ogy is restricted by cuttings accumulation in the wellbore due to non-rotation of the drill string and limited circulating capacity.Cuttings cleaning becomes more difficult with the wall resistance of pipe-wellbore annulus on the cutting transport.Accurate description of particle transport process in the pipe-wellbore annulus is,therefore,important for improving the wellbore cleanliness.In this study,high-speed cam-era is used to record and analyze the settling process of particles in the transparent annulus filled with power-law fluids.A total of 540 tests were carried out,involving dimensionless diameters of 0.10-0.95 and particle Reynolds Numbers of 0.01-12.97,revealing the effect of the dimensionless diameter and particle Reynolds number on the annulus wall effect,and the wall factor model with an average relative error of2.75%was established.In addition,a dimensionless parameter,Archimedes number,independent of the settling velocity,was introduced to establish an explicit model of the settling velocity of spherical particles in the vertical annulus,with the average relative error of 7.89%.Finally,a calculation example was provided to show how to use the explicit model of settling velocity in annulus.The results of this study are expected to provide guidance for field engineers to improve the wellbore cleanliness of coiled tubing drilling. 展开更多
关键词 Coiled tubing drilling Micro annulus Spherical particle Wall effect Settling velocity
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Controllable preparation of particles with microfluidics 被引量:16
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作者 Guangsheng Luo Le Du Yujun Wang Yangcheng Lu Jianhong Xu 《Particuology》 SCIE EI CAS CSCD 2011年第6期545-558,共14页
This paper reviews recent development and achievements in controllable preparation of nanoparticles, micron spherical and non-spherical particles, using microfluidics. A variety of synthesis strategies are presented a... This paper reviews recent development and achievements in controllable preparation of nanoparticles, micron spherical and non-spherical particles, using microfluidics. A variety of synthesis strategies are presented and compared, including single-phase and multiphase microflows. The main structures of microfluidic devices and the fundamental principles of microflows for particle preparation are summarized and identified. The controllability of particle size, size distribution, crystal structure, morphology, physical and chemical properties, is examined in terms of the special features of microfluidic reactors. An outlook on opinions and predictions concerning the future development of powder technology with microfluidics is specially provided. 展开更多
关键词 Microfluidics Nanoparticles Micron spherical particles Micron non-spherical particles Preparation technology
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Efficient approaches of determining the motion of a spherical particle in a swirling fluid flow using weighted residual methods 被引量:2
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作者 Seiyed E. Ghasemi M. Vatani D.D. Ganji 《Particuology》 SCIE EI CAS CSCD 2015年第6期68-74,共7页
The motion of a spherical particle released in a swirling fluid flow is studied employing the least-squares method and method of moments. The governing equations are obtained and solved employing the two methods. The ... The motion of a spherical particle released in a swirling fluid flow is studied employing the least-squares method and method of moments. The governing equations are obtained and solved employing the two methods. The accuracy of the results is examined against the results of a fourth-order Runge-Kutta numer- ical method. The effects of various parameters, namely the initial radius, initial radial velocity, initial angular velocity, and drag-to-inertia ratio, on the non-dimensional velocity profiles and particle position distribution are considered. The results show that the radial velocity increases over time while the angular velocity decreases, and that an increase in the initial radial velocity increases the particle radial distance and angular velocity but decreases the radial velocity profile. 展开更多
关键词 Spherical particle Swirling flow Radial velocity Angular velocity Least-squares method Method of moments
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