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Effects of finite-size neutrally buoyant particles on the turbulent channel flow at a Reynolds number of 395

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Applied Mathematics and Mechanics(English Edition) 2019年第2期40卷 293-304页

作者： zhaosheng yu Chenlin ZHU yu WANG Xueming SHAO State Key Laboratory of Fluid Power and Mechatronic System Department of MechanicsZhejiang University

A direct-forcing fictitious domain(DFFD) method is used to perform fully resolved numerical simulations of turbulent channel flows laden with large neutrally buoyant particles. The effects of the particles on the turbulence(including the mean velocity,the root mean square(RMS) of the velocity fluctuation, the probability density function(PDF) of the velocity, and the vortex structures) at a friction Reynolds number of 395 are investigated. The results show that the drag-reduction effect caused by finite-size spherical particles at low particle volumes is negligibly small. The particle effects on the RMS velocities at Re_τ = 395 are significantly smaller than those at Re_τ = 180, despite qualitatively the same effects, i.e., the presence of particles decreases the maximum streamwise RMS velocity near the wall via weakening the large-scale streamwise vortices,and increases the transverse and spanwise RMS velocities in the vicinity of the wall by inducing smaller-scale vortices. The effects of the particles on the PDFs of the fluid fluctuating velocities normalized with the RMS velocities are small, regardless of the particle size, the particle volume fraction, and the Reynolds number.

关键词： turbulent channel flow finite-size particle direct numerical simulation(DNS)

Combination of direct-forcing fictitious domain method and sharp interface method for dielectrophoresis of particles

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Particuology 2010年第4期8卷 351-359页

作者： Yang Shi zhaosheng yu Xueming Shao State Key Laboratory of Fluid Power Transmission and Control Department of Mechanics. Zhejiang University Hangzhou 310027 China

In this paper, we combine the direct-forcing fictitious domain （DF/FD） method and the sharp interface method to resolve the problem of particle dielectrophoresis in two dimensions. The flow field and the motion of particles are solved with the DF/FD method, the electric field is solved with the sharp inter- face method, and the electrostatic force on the particles is computed using the Maxwell stress tensor method. The proposed method is validated via three problems： effective conductivity of particle compos- ite between two planar plates, cell trapping in a channel, and motion of particles due to both conventional and traveling wave dielectrophoretic forces.

关键词： Direct-forcing fictitious domain method Sharp interface methodMaxwell stress tensor method Dielectrophoresis Direct numerical simulation Cell trapping

Hydrodynamics characterization of a choanoid fluidized bed bioreactor used in the bioartificial liver system： Fully resolved simulation with a fctitious domain method

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Particuology 2017年第3期15卷 39-48页

作者： Jingyuan Sun zhaosheng yu Shangjun Ye Department of Mechanics State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University Hangzhou 310027 China

Choanoid fluidized bed bioreactors （CFBBs） are newly developed core devices used in bioartificial liver- support systems to detoxify blood plasma of patients with microencapsulated liver cells. Direct numerical simulations （DNS） with a direct-forcing/fictitious domain （DF/FD） method were conducted to study the hydrodynamic performance of a CFBB. The effects of particle-fluid density ratio, particle number, and fil- ter screens preventing particles flowing out of the reactor were investigated. Depending on density ratio, two flow patterns are evident： the circulation mode in which the suspension rises along one sidewall and descends along the other sidewall, and the non-circulation mode in which the whole suspension roughly flows upward. The circulation mode takes place under non-neutral-buoyancy where the particle sedimentation dominates, whereas the non-circulation mode occurs under pure or near-neutral buoy- ancy with particle-fluid density ratios of unity or near unity. With particle-fluid density ratio of 1.01, the bioartificial liver reactor performs optimally as the significant particle accumulation existing in the non-circulation mode and the large shear forces on particles in the circulation mode are avoided. At higher particle volume fractions, more particles accumulate at the filter screens and a secondary counter circulation to the primary flow is observed at the top of the bed. Modelled as porous media, the filter screens play a negative role on particle fluidization velocities; without screens, particles are fluidized faster because of the higher fluid velocities in the jet center region. This work extends the DF/FD-based DNS to a fluidized bed and accounts for effects from inclined side walls and porous media, providing some hydrodynamics insight that is important for CFBB design and operation optimization.

关键词： Choanoid fluidized-bed bioreactor Particle-laden flows Direct numerical simulation Direct-forcing/fctitious domain method Hydrodynamic characteristics

碳减排约束下不同能源类型垃圾转运车适用性竞争力分析——以深圳市为例

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环境卫生工程 2024年第3期32卷 1-8页

作者：彭晓为唐玉婷钟日钢余昭胜林延吴浩东莞职业技术学院智能汽车产教融合创新中心广东东莞523000 华南理工大学电力学院广东广州510640 惠州深能源丰达电力有限公司广东惠州516000 中国科学院广州能源研究所广东广州510640 深圳能源环保股份有限公司广东深圳518000

以柴油、LNG、纯电动和氢能垃圾转运车为研究对象,从车辆的续航能力、全生命周期使用成本、碳排放水平、长期竞争力等不同维度对车辆的适用性进行综合对比研究。结果表明:纯电动转运车受限于续航里程短、充电时间长,在8 h连续工作时间内... 详细信息

以柴油、LNG、纯电动和氢能垃圾转运车为研究对象,从车辆的续航能力、全生命周期使用成本、碳排放水平、长期竞争力等不同维度对车辆的适用性进行综合对比研究。结果表明:纯电动转运车受限于续航里程短、充电时间长,在8 h连续工作时间内,其工作临界运距为23.7 km;基于全生命周期使用成本和未来碳价上涨趋势,相比于LNG转运车,短运距(≤23.7 km)情景下氢能和纯电动转运车的竞争力时间点分别为2030年和2050年;长运距(>23.7 km)情景下,氢能转运车竞争力时间点为2035年,但纯电动转运车长期不具备竞争优势;现阶段垃圾转运车清洁化替代方案宜采用“以气为主、电氢为辅”的策略,并以场景为导向构建差异化的综合能源补给设施。

关键词：生活垃圾转运能源类型碳排放竞争力

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红层泥岩路基填料分类与高效利用技术

公路工程 2024年第4期49卷 51-56,94页

作者：陈晓斌喻昭晟李志勇周雨晴刘先锋中南大学土木工程学院湖南长沙410018 湖南省交通科学研究院有限公司湖南长沙410114 西南交通大学土木工程学院四川成都610031

红层泥岩广泛分布于我国的西南、西北、华中及华南地区,就近采用红层泥岩填筑路基有助于提高经济效益、降低能源消耗、减小环境破坏,然而红层填料的高效利用技术还有待开展进一步研究。由于红层泥岩特殊的水理特性,红层泥岩的科学分类... 详细信息

红层泥岩广泛分布于我国的西南、西北、华中及华南地区,就近采用红层泥岩填筑路基有助于提高经济效益、降低能源消耗、减小环境破坏,然而红层填料的高效利用技术还有待开展进一步研究。由于红层泥岩特殊的水理特性,红层泥岩的科学分类极其重要,不同等级的红层泥岩需要不同的工程处置方法,对红层泥岩进行科学的分类是高效利用红层泥岩的前提。基于红层泥岩路基病害调研,分析了病害产生的原因及分类。通过岩石耐崩解试验及DEM数值模拟揭示了“湿度-荷载”耦合下红层泥岩的宏观及细观崩解机制,得到了耐久性控制指标。基于耐崩解指数I d的红层泥岩分类方法可有效区分不同红层泥岩填料长期工程特性。最终总结了红层泥岩填料高效利用技术,并成功运用于实际工程施工中。

关键词：路基填料红层泥岩崩解指标填料分类利用技术

NUMERICAL FLOW VISUALIZATION OF A MIXING LAYER

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Journal of Hydrodynamics 1998年第4期10卷 45-53页

作者： Lin, Jianzhong yu, zhaosheng Shao, Xueming Zhejiang Univ Hangzhou China

Kelvin-Helmhotz roll up of the 3-D time-developing mixing was simulated numerically. The dye lines or fluid interfaces were presented by computing a passive scalar at high Peclet number. The hydric bubbles were also simulated numerically. To help understanding the visualization results, the behaviour of coherent structures were analyzed. A comparison between vortical structure and passive scalar contours indicates that the wrapping by the vortices largely dominates the evolution of passive scalar.

关键词： Bubbles (in fluids) Computer applications Flow of water Hydrodynamics Laminar flow Turbulent flow

Lattice water fuels acidic water oxidation

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Science China Chemistry 2024年第7期67卷 2132-2133页

作者： Minyue Zhao Jianyong Feng zhaosheng Li Zhigang Zou Collaborative Innovation Center of Advanced Microstructures National Laboratory of Solid State MicrostructuresCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210093China Jiangsu Key Laboratory for Nano Technology Nanjing UniversityNanjing 210093China

In comparison to commercial alkaline water electrolysis technologies,proton-exchange membrane water electrolyzers(PEMWEs)offer intriguing advantages for hydrogen production,such as high current density,compact system ... 详细信息

关键词： Lattice alkaline system

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Slip rate and interseismic coupling along the Moxi-Shimian segment of the Xianshuihe fault, Eastern Qinghai-Xizang Plateau

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Geodesy and Geodynamics 2024年第4期15卷 338-351页

作者： Xinyu Zhao Gang Liu zhaosheng Nie Wei Xiong Wei Chen Mu Lin Dijin Wang Qi Li Jiansheng yu Dongzhen Wang Pengfei yu Institute of Seismology China Earthquake AdministrationWuhan 430071China Key Laboratory of Earthquake Geodesy.China Earthquake Administration Wuhan 430071China State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China

On September 5,2022,the Luding M6.8 earthquake occurred in the Moxi-Shimian segment of the Xianshuihe fault,coinciding with the historical ruptured zone of the 1786 Moxi *** seis-mogenic environment provides a foundation for comprehending the mechanism of the earthquake and its future *** the Moxi-Shimian segment,we establish a series of near-field Global Navigation Satellite Systems(GNsS)stations to enhance the spatial resolution of observational data for the inversion of the interseismic kinematic *** this study,with an elastic screw dislocation model con-strained by GNsS observations,the slip rate of the Moxi-Shimian segment is estimated to be 10.9±1.0 mm/yr,while the locking depth is 15.7±6.2 ***,we utilize a block-dislocation model to invert the interseismic fault coupling along the Kangding-Moxi-Shimian *** result indicates a gradual deepening of the locking depth along the section from Kangding to *** coseismic rupture of the 2022 event occurred within the high coupling regions in the Kangding-Moxi-Shimian segment,which indicates that the rupture kinematics in this event might be controlled by the interseismic *** seismic moment accumulated within the ruptured zone of the Luding earthquake since 1786 ranges in[1.42-3.40]×10^(19) N-m,which is significantly greater than the seismic moment released during the 2022 *** a result,we infer that the Luding earthquake released only a portion of the accumulated energy within the original rupture zone since 1786,indicating that the 2022 event has not caused a complete rupture in the Moxi-Shimian ***,there remains a substantial seismic hazard in this area.

关键词： Moxi-Shimian segment of Xianshuihe fault Luding earthquake Global positioning system Interseismic kinematic parameters

Geochemical Characteristics and Hydrocarbon Generation Modeling of the Paleocene Source Rocks in the Jiaojiang Sag,East China Sea Basin

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Journal of Earth Science 2024年第2期35卷 642-654页

作者： Chuang Lei Shiyan Yin Jiaren Ye Jingfu Wu zhaosheng Wang Bin Gao Collaborative Innovation Center of Green Development and Ecological Restoration of Mineral Resources North China University of Science and TechnologyTangshan063210China Key Laboratory of Tectonics and Petroleum Resources China University of GeosciencesMinistry of EducationWuhan430074China CNOOC Research Institute Ltd Beijing100028China

Jiaojiang sag in the East China Sea Basin is at the earlier exploration stage,where characterizing hydrocarbon generation of source rocks is important to understand oil-gas exploration *** geochemical and basin modeling analysis,hydrocarbon generation capacity and process of the Paleocene E_(1)y,E_(1)l and E_(1)m formations were *** show that E_(1)y and E_(1)l mudstones are high-quality source rocks with Type Ⅱ kerogen,which is dominated by both aquatic organisms and terrestrial higher plants deposited in sub-reduced environment.E_(1)m mudstone interbedded with thin carbonaceous mudstone and coal is poor-quality source rock with Type Ⅲ kerogen,whose organic matter was originated from terrestrial higher plants under oxidized *** by burial and maturity histories,E_(1)y and E_(1)l source rocks experienced two hydrocarbon generation stages,which took place in the Late Paleocene and in the Middle to Late Eocene,respectively,and had high hydrocarbon generation capacity with cumulative hydrocarbon volume of 363 and 328 mg/g,respectively.E_(1)m source rock only had one hydrocarbon generation process in the Late Eocene,which had low hydrocarbon generation capacity with cumulative hydrocarbon volume of only 24 mg/*** future oil-gas exploration in the Jiaojiang sag should focus on hydrocarbon generation center and select targets in the central uplift formed before the Miocene with high-quality traps.

关键词： East China Sea Basin Jiaojiang sag source rock geochemical characteristics hydrocarbon generation basin modeling petroleum geology