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Numerical Simulation of the Vortex-Induced Vibration of A Curved Flexible Riser in Shear Flow

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China Ocean Engineering 2018年第3期32卷 301-311页

作者： ZHU Hong-jun lin peng-zhi State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University

A series of fully three-dimensional(3 D) numerical simulations of flow past a free-to-oscillate curved flexible riser in shear flow were conducted at Reynolds number of 185–1015. The numerical results obtained by the two-way fluid–structure interaction(FSI) simulations are in good agreement with the experimental results reported in the earlier study. It is further found that the frequency transition is out of phase not only in the inline(IL) and crossflow(CF) directions but also along the span direction. The mode competition leads to the non-zero nodes of the rootmean-square(RMS) amplitude and the relatively chaotic trajectories. The fluid–structure interaction is to some extent reflected by the transverse velocity of the ambient fluid, which reaches the maximum value when the riser reaches the equilibrium position. Moreover, the local maximum transverse velocities occur at the peak CF amplitudes, and the values are relatively large when the vibration is in the resonance regions. The 3 D vortex columns are shed nearly parallel to the axis of the curved flexible riser. As the local Reynolds number increases from 0 at the bottom of the riser to the maximum value at the top, the wake undergoes a transition from a two-dimensional structure to a 3 D one. More irregular small-scale vortices appeared at the wake region of the riser, undergoing large amplitude responses.

关键词： vortex-induced vibration flexible riser shear flow fluid–structure interaction computational fluid dynamics

Depth-resolved numerical model of dam break mud flows with Herschel-Bulkley rheology

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Journal of Mountain Science 2022年第4期19卷 1001-1017页

作者： TANG Jin-bo lin peng-zhi CUI peng State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China Key Laboratory of Mountain Hazards and Earth Surface Processes Chinese Academy of SciencesInstitute of Mountain Hazards and EnvironmentChinese Academy of Sciences and Ministry of Water ConservancyChengdu 610041China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Mud flows are common phenomena in mountainous areas,which can threaten human safety and cause property losses under certain extreme *** the dynamic characteristics of mud flows,especially in the vertical direction,is helpful for risk reduction and hazard *** this study,a 2D depth-resolved numerical model based on Herschel-Bulkley rheology was developed to study the vertical structures of unsteady mud flows with a *** numerical model was solved by the projection method,and the free surface of mud flows was captured through the VOF *** fully validate this new model,a series of laboratory experiments involving dam break mud flows were conducted,and the mud flow heights,bottom pressures and envelopes of mud residuum were *** numerical model proposed in this study was first validated by the steady-state solution for uniform flows of Herschel-Bulkley fluid on an inclined ***,the simulated and measured mud flow heights,bottom pressures at different x locations and envelopes with different bed slopes showed good ***,the numerical results for a Herschel-Bulkley fluid dam break flow were used to validate the proposed model,which further revealed good *** that,the scenarios in which mud flows impact on a structure were numerically studied,and the vertical profiles of the front velocity and impact pressure on the structure were analyzed and *** results show that a plug layer was formed in the mud flow under unsteady and nonuniform flow conditions,and the impact pressure on the structure was dominated by the dynamic *** addition,the vertical position with the maximum impact pressure acting on the structure was not at the bottom or the surface of the mud flows,and the normalized vertical position rose as the yield stress and consistency coefficient increase for Herschel-Bulkley fluids.

关键词： Mud flows Herschel-Bulkley rheology Depth-resolved model Numerical simulation Vertical profiles

A NOVEL ADAPTIVE σ COORDINATE MODEL AND ITS APPLICATIONS TO WAVE AND STRUCTURE INTERACTION

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Journal of Hydrodynamics 2012年第3期24卷 323-331页

作者： SU Xiao-hui ZOU De-gao ZHANG Jian-tao LESCHKA Stefan lin peng-zhi ZHANG Kai-lin School of Energy and Power Engineering Dalian University of Technology Dalian 116023 China Institute of Earthquake Engineering Dalian University of Technology Dalian 116024 China Institute of Water Resource and Hydropower Dalian University of Technology Dalian 116023 China DHI-NTU Water and Environment Research Center and Education Hub Singapore 760330 College of Water Resource and Hydropower Sichuan University Chengdu 610065 China

In this paper, a novel adaptive mesh σ coordinate model is proposed for the studies of Wave and Structure Interaction （WSI）. The model is validated by using the case of a solitary wave movement in an open channel with constant water depth and the case of nonbreaking solitary wave propagating over a step. Numerical results agree well with the analytical solutions obtained based on the Boussinesq theory, the laboratory data and other numerical model results. The proposed model is then used to study a solitary wave interacting with a suspended fixed structure.

关键词： adaptive mesh σ coordinate solitary wave wave structure interaction

Numerical Studies of Turbulent Flows in Channels with Abrupt Cross-sectional Changes

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南水北调与水利科技 2013年第1期11卷 J0007-J0015页

作者： CHEN Hao-liang lin Quan-hong Cheong Hin Fatt lin peng-zhi Singapore-MIT Alliance for Research and Technology Singapore 138602 Department of Civil & Environmental Engineering National University of Singapore Singapore 117576 State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065 China

The turbulent flows through the channels with abrupt cross-sectional changes are common and importantphysical process in *** a better prediction of the mean flow and turbulent characteristics for this problem,atwo-dimensional depth-averaged numerical model is *** model is robust and accurate in reproducing therecirculation flow behind a groyne and turbulent flows in channels with abrupt cross-sectional changes,when com-pared to the available experimental data of mean velocities and turbulence kinetic *** results reveal that theabrupt cross-sectional change of a channel can affect the flow pattern significantly and introduces the complex turbu-lence *** particular,when the channel has an abrupt expansion,the mean flow pattern is mainly in lon-gitudinal direction with rather small transverse ***,a recirculating region forms behind the expan-sion position and the turbulence has very strong intensity within this *** the flow in the channel with an ab-rupt contraction,the longitudinal component of the flow is decreased by the obstruction on one side and accelerated onthe other side,whereas the transverse velocity is *** turbulence is extraordinarily strong in the regions adja-cent to the contraction wall in the narrow *** both cases of abrupt cross-sectional changes,the TKE is genera-ted dominantly by the shear of the longitudinal velocities.

关键词： turbulent flow open channel abrupt expansion abrupt contraction shallow water equation

High-Performance Germanium Waveguide Photodetectors on Silicon

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Chinese Physics Letters 2020年第3期37卷 81-85页

作者： Xiu-Li Li zhi Liu lin-zhi peng Xiang-Quan Liu Nan Wang Yue Zhao Jun Zheng Yu-Hua Zuo Chun-Lai Xue Bu-Wen Cheng State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083 Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049

Germanium waveguide photodetectors with 4μm widths and various lengths are fabricated on silicon-on-insulator substrates by selective epitaxial *** dependence of the germanium layer length on the responsivit.y and bandwidth of the photodetectors is *** optimal length of the germanium layer to achieve high bandwidth is found to be approximately 8μ*** the 4×8μm^2 photodetector,the dark current density is as low as 5 mA/cm^2 at^-1 *** a bias of-1 V,the 1550 nm optical responsivity is as high as 0.82 A/*** as high as 29 GHz is obtained at-4 *** opened eye diagrams at 50 Gbits/s are demonstrated at 1550 nm.

关键词： waveguide Waveguide Germanium

Design and Implementation of WebGIS Based on SOAP

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Wuhan University Journal of Natural Sciences 2003年第04A期8卷 1085-1089页

作者： Feng Yu-cai, Yi Bao-lin, Tan zhi-peng College of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China College of Computer Science and Technology Huazhong University of Science and Technology Wuhan Hubei China

Most popular applications currently running on the Internet, the World Wide Web is of an exponential growth in size, which results in network congestion and server overloading. In this paper, we analyze the characteristics of SOAP (Simple Object Access Protocol) and the state-of-art techniques, which have been used in WebGIS. Then, the basic characteristics of DM3 database system were introduced; Furthermore, a novel N-tier WebGIS architecture based on SOAP and the framework supported both server-based and client\|based solutions are proposed. Finally, some experiments and implementations are shown.

关键词： SOAP WebGIS spatial databases

Study of River Water Environment Simulation on WebGIS

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International English Education Research 2014年第3期 58-62页

作者： Niu Maojing Liu Xing lin peng Wu zhi Han Kai (Anhui University of Science & Technology Huaman Anhui 232001

Along with economic development, river pollution has become a serious phenomenon. It＇s rational to simulate variation of pollutants by using water quality model. Thus, relevant departments could take appropriate measures to improve the water environment. However, the traditional image of mathematical modeling is not intuitive. The advantage of WebGIS is the ability of visualization on web browser by the combination ofgeospatial data and pollution attribute data.

关键词： WebGIS: River: Water Quality Model.

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废旧聚苯乙烯(泡沫)塑料资源化综述

塑料工业 2005年第B5期33卷 31-33页

作者：林志鹏福建省福建师范大学化学与材料学院福建福州350007

介绍了废旧聚苯乙烯(泡沫)塑料应用较广泛的资源化技术,包括建材利用、再生利用、改性再利用、焚烧和热解,并介绍了各项技术的新进展。

关键词：废旧聚苯乙烯泡沫综述资源化技术塑料应用再生利用再利用焚烧

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上博馆藏楚竹书《周易》校释七则

周易研究 2009年第2期 7-11页

作者：林志鹏北京大学中国语言文学系北京100871

本文对上海博物馆藏战国楚竹书《周易》简文中部份疑难字词提出解释,如将第十四简"可豫悔"、"猷豫"释为"歌豫悔"、"谣豫";释第二十一简"勿药有菜"为"勿药有瘥";释简二十四"■经于北涯"为"拂径于丘、洍"。并讨论第二简的"■"、第十五简的... 详细信息

本文对上海博物馆藏战国楚竹书《周易》简文中部份疑难字词提出解释,如将第十四简"可豫悔"、"猷豫"释为"歌豫悔"、"谣豫";释第二十一简"勿药有菜"为"勿药有瘥";释简二十四"■经于北涯"为"拂径于丘、洍"。并讨论第二简的"■"、第十五简的"■"等字。透过本文的讨论,对于许多《周易》爻辞的文义可以得到较清楚的理解。

关键词：周易楚竹书爻辞