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Cuttings transport: Back reaming analysis based on a coupled layering-sliding mesh method via CFD

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Petroleum Science 2023年第6期20卷 3673-3686页

作者： Na Zhu Shi-Dong Ding Xiao-Lei Shi Wen-Jun Huang De-Li Gao MOE Key Laboratory of Petroleum Engineering China University of PetroleumBeijing102249China SINOPEC Research Institute of Petroleum Engineering Co.Ltd No.197 Baisha RoadChangping DistrictBeijing102206China

Inadequate hole cleaning is one of the main reasons for inefficient operations in extended-reach drilling.The mechanism of cuttings transport under the back reaming operation,which is frequently adopted to remove the cuttings,has been investigated in this study.To this end,a coupled layering-sliding mesh method with the Eulerian-Granular approach has been established innovatively.The dynamic layering method has been employed to simulate the axial motion of the pipe,whereas the sliding mesh method has been used to simulate the pipe rotation.The back reaming operation of a connector-furnished pipe has been simulated,and the sensitive parameter analysis has been conducted.The results thus obtained demonstrate that the increase in the initial bed height,inclination,and the diameter and length of the connector causes a significant increase in the cuttings concentration.In addition,the cuttings concentration is observed to decrease significantly with the pipe rotation speed.Furthermore,two main factors contribute towards the cuttings accumulation around the connector,namely,the difference in the cross-sectional area and the pushing effect of the connector—like a“bulldozer”.The“bulldozer”effect of the connector dominates when the tripping velocity is significant compared to the velocity of the cuttings.Conversely,the effect of the difference in the cross-sectional area becomes the leading factor for cuttings accumulation.The“bulldozer”effect of the connector causes a more severe impact on hole cleaning.In both cases,increasing the tripping velocity only mildly affects the cuttings concentration.It is therefore suggested that the tripping velocity should be slower than that of the sand during the back reaming operation.Furthermore,increased fluid velocity might lead to a higher accumulated cuttings concentration around the connector when the cuttings bed has not entirely passed through the connector.A significant flow rate can be safely applied after the cuttings have passed through the connector furnished with a large d

关键词： Drill cuttings transport Back reaming Layering-sliding mesh Hole cleaning connector

基于ArcIMS Java connector与Ajax技术构建林业WebGIS

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北京林业大学学报 2008年第S1期30卷 11-14页

作者：冯仲科祝晓轶李亚东聂敏莉隋宏大山东省林业科学研究院北京林业大学测绘与3S技术中心中国计量科学研究院热工处

该文为了解决在林业WebGIS开发中大数据量的服务器端实时验证和提高用户体验,通过将Ajax技术与ArcIMS Java connector相结合的方法,实现了林业WebGIS的大数据的服务器实时验证、记录的无刷新分页显示、无刷新的地图操作、可拖拽UI界面... 详细信息

该文为了解决在林业WebGIS开发中大数据量的服务器端实时验证和提高用户体验,通过将Ajax技术与ArcIMS Java connector相结合的方法,实现了林业WebGIS的大数据的服务器实时验证、记录的无刷新分页显示、无刷新的地图操作、可拖拽UI界面等传统方式所无法实现的功能。在林业WebGIS上实现了将两种技术成功集成的例子。

关键词： ArcIMS Java connector Ajax WebGIS

Seismic behavior of large-scale FRP–recycled aggregate concrete–steel columns with shear connectors

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Earthquake Engineering and Engineering Vibration 2019年第4期18卷 823-844页

作者： Zeng Lan Li Lijuan Yang Xianqian Liu Feng School of Civil and Transportation Engineering Guangdong University of Technology Guangzhou 510006 China MOE Key Laboratory of Disaster Forecast and Control in Engineering School of Mechanics and Construction Engineering Jinan University Guangzhou 510632 China Architectural Design and Research Institute of Guangdong Province Guangzhou 510000 China

The application of fi ber-reinforced polymer (FRP) composites for the development of high-performance composite structural systems has received signifi cant recent research attention. A composite of FRP–recycled aggregate concrete (RAC)–steel column (FRSC), consisting of an outer FRP tube, an inner steel tube and annular RAC fi lled between two tubes, is proposed herein to facilitate green disposal of demolished concrete and to improve the ductility of concrete columns for earthquake resistance. To better understand the seismic behavior of FRSCs, quasi-static tests of large-scale basalt FRSCs with shear connectors were conducted. The infl uence of the recycled coarse aggregate (RCA) replacement percentage, shear connectors and axial loading method on the lateral load and deformation capacity, energy dissipation and cumulative damage were analyzed to evaluate the seismic behavior of FRSCs. The test results show that FRSCs have good seismic behavior, which was evidenced by high lateral loads, excellent ductility and energy dissipation capacity, indicating RAC is applicable in FRSCs. Shear connectors can signifi cantly postpone the steel buckling and increase the lateral loads of FRSCs, but weaken the deformation capacity and energy dissipation performance.

关键词： recycled aggregate concrete (RAC) fi ber-reinforced polymer (FRP) FRP–RAC–steel column (FRSC) shear connector seismic behavior

A Position and Orientation Compensation Mechanism for Automatic Docking Device of Launch Rocket

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第6期35卷 1064-1072页

作者： Zhou Cheng Yu Cungui School of Mechanical Engineering Nanjing University of Science and Technology

A position and orientation compensation mechanism for the automatic docking device of a launch rocketwas established.The docking process was simulated,and the maximum docking deviation was used for the prototype testing of the compensation mechanism.The compensation mechanism mainly comprises four column pairmotion branch chains with the same structure.When the position of the ground connector panel changes relative to the moving platform,the sliding rods in the four motion branch chains move and rotate to either compress or stretch the connected spring,thereby compensating the position and orientation.First,the dynamic simulation model of the compensation mechanism was established.The docking process was then simulated under the maximum docking deviation.Bench testing of the automatic docking device prototype was carried out.Afterwards,the device was manufactured,and a maximum load test and maximum deviation test were carried out.The results demonstrate that the compensation mechanism meets the design requirements,and the spring stiffness was found as the most important factor in determining the mechanical properties of the system.The proposed compensation mechanism has a number of advantages,including a simple structure,large load bearing capacity,small size,simple installation,and adjustment.

关键词： priming connector position and orientation compensation mechanism spring dynamic simulation prototype test

Numerical Simulation of Mechanical Characteristics of a Metal Net for Deep-Sea Aquaculture

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Journal of Ocean University of China 2019年第6期18卷 1273-1281页

作者： CHEN Changping LIU Hangfei HUANG Yu YANG Jie LIANG Xinyu ZHANG Chaobi LOU Yafei ZHANG Yu Liaoning Provincial Key Laboratory of Coastal Engineering Dalian Ocean UniversityDalian 116023China Key Laboratory of Environment Controlled Aquaculture Ministry of EducationDalian 116023China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

The investigation on hydrodynamic characteristics of a cage is important for its application in the deep-sea aquaculture in our country.With finite element method,the beam element is used to simulate a three-dimensional metal chain net,and the connector element is introduced as the interaction between metal net lines.A mechanical model for the metal net is constructed to simulate the hydrodynamic characteristics of a metal net subjected to fluid current forces.The static simulation results show that the relative errors of the displacements are 2.13%,4.19%,6.64%,and 11.35% compared with static concentrated load tests under concentrated forces of 20,40,60,and 80 N,respectively.Both the transient hydrodynamic deformations and drag forces of the netting structures under different current velocities are obtained by solving the hydrodynamic equation of the netting structure.The average relative error of the current forces obtained by numerical simulations shows an 8.13%deviation from the drag tests of the metal nets in the tank under five current velocities.The effectiveness and precision of the simulation approach are verified by static and dynamic tests.The proposed simulation approach will provide a good foundation for the further investigation of the hydrodynamic characteristics of deep-sea aquaculture metal cages and the parameter design for the safety of such cage systems.

关键词： metal net finite element method connector element mechanical characteristics numerical simulation

3D defect detection of connectors based on structured light

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Optoelectronics Letters 2021年第2期17卷 107-111页

作者：纪越陈扬宋丽梅杨燕罡杨怀栋 Key Laboratory of Advanced Electrical Engineering and Energy Technology Tiangong UniversityTianjin 300387China School of Mechanical Engineering Tianjin University of Technology and EducationTianjin 300222China Department of Precision Instrument Tsinghua UniversityBeijing 100084China

In order to realize the rapid detection of three-dimensional defects of connectors, this paper proposes a method for detecting connector defects based on structured light. This method combines structured light with binocular stereo vision to obtain three-dimensional data for the connector. Point cloud registration is used to identify defects and decision trees are used to classify defects. The accuracy of the 3D reconstruction results in this paper is 0.01 mm, the registration accuracy of the point cloud reaches the sub-millimeter level, and the final defect classification accuracy is 94%. The experimental results prove the effectiveness of the proposed three-dimensional connector defect detection method in connector defect detection and classification.

关键词： defect connector light

SOFTWARE RELIABILITY MODEL FOR COMPONENT INTERACTION MODE

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Journal of Electronics(China) 2011年第4期28卷 632-642页

作者： Wang Qiang Lu Yang Xu Zijun Han Jianghong School of Computer ＆ Information Hefei University of Technology Hefei 230009 China GOCOM Information Technology Co. LTD Hefei 230088 China

With the rapid progress of component technology,the software development methodology of gathering a large number of components for designing complex software systems has matured.But,how to assess the application reliability accurately with the information of system architecture and the components reliabilities together has become a knotty problem.In this paper,the defects in formal description of software architecture and the limitations in existed model assumptions are both analyzed.Moreover,a new software reliability model called Component Interaction Mode(CIM) is proposed.With this model,the problem for existed component-based software reliability analysis models that cannot deal with the cases of component interaction with non-failure independent and non-random control transition is resolved.At last,the practice examples are presented to illustrate the effectiveness of this model.

关键词： Component connector Software architecture Reliability model

OPTICAL TELEPHONE CORD PASSING THROUGH LONG PIPE WITH SPIRAL FLOW

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Chinese Journal of Aeronautics 1991年第2期6卷 133-140页

作者： K.Horii Y.Matsumae Cheng Xiaoming M.Takei E.Yasukawa B.Hashimoto Shirnyuri Women's College 1-25 Midorigaoka Chofu-shi Tokyo 182 JAPAN Shirnyuri Women's College 1-25 Midorigaoka Chofu-shi Tokyo 182 JAPANShirnyuri Women's College 1-25 Midorigaoka Chofu-shi Tokyo 182 JAPANShirnyuri Women's College 1-25 Midorigaoka Chofu-shi Tokyo 182 JAPANShirnyuri Women's College 1-25 Midorigaoka Chofu-shi Tokyo 182 JAPANShirnyuri Women's College 1-25 Midorigaoka Chofu-shi Tokyo 182 JAPAN

A new effective technique, useful in telecommunications industry for passing an optical telephone cord attached to a connector through pipeline,has been developed using the spiral flow. Using this technique, the cord could be passed through a straight pipeline 150 meters long and a roll of vinyl tube 50 meters long. However, under the same condition, the cord could not pass through when using the turbulent flow. To obtain a high speed stable spiral flow, a nozzle with an annular slit connected to a conical cylinder was used. A pressurized fluid with no tangential flow was supplied through this slit and the fluid, passing through the conical cylinder, was deformed into spiral flow with the steeper axial velocity distribution compared to that of turbulence pipe flow due to Coanda effect and instability. As a result, the cord was attracted to the axis area of the pipe, which effectively increased the ability for the work of cord passing. This high ability for cord passing is attributed mainly to the

关键词： turbulent turbulence cylinder passing pipeline deformed straight tangential connector Reynolds

Academic health sciences libraries as connectors to knowledge beyond literature

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中华医学图书情报杂志 2018年第1期27卷 6-10页

作者： Paul Schoening Bernard Becker Medical Library Washington University in St. Louis660 South Euclid Avenue Campus Box 8132 St. Louis Missouri USA 63110

Libraries at large academic medical centers in the United States are undergoing a transformation from their traditional role as knowledge repositories to a new role as connectors to knowledge. This transformation is fueled by the move away from library-held print resources as the primary source of information used by researchers,clinicians and students. Knowledge resources critical to the missions of academic medical centers now include online books and journals,very large data sets,software tools,and expertise far beyond the walls of the library. This article illustrates how Bernard Becker Medical Library at Washington University in St. Louis has seized the opportunity to recast itself as a connector to knowledge beyond literature and strengthen its vital role within the university as a catalyst for learning and discovery.

关键词： Knowledge repositories connector Knowledge resources Academic medical centers Recast Beyond literature