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NUMERICAL MODELING OF WAVE EVOLUTION AND RUNUP IN SHALLOW WATER

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Journal of Hydrodynamics 2009年第6期21卷 731-738页

作者： DONG Zhi ZHAN Jie-min Department of Applied Mechanics and engineering Sun Yat-sen University Guangzhou 510275 China guangdong province key laboratory of coastal ocean engineering Sun Yat-sen University Guangzhou 510275China

Based on the Navier-Stokes （N-S） equations for viscous, incompressible fluid and the VOF method, 2-D and 3-D Numerical Wave Tanks （NWT） for nonlinear shallow water waves are built. The dynamic mesh technique is applied, which can save computational resources dramatically for the simulation of solitary wave propagating at a constant depth. Higher order approximation for cnoidal wave is employed to generate high quality waves. Shoaling and breaking of solitary waves over different slopes are simulated and analyzed systematically. Wave runup on structures is also investigated. The results agree very well with experimental data or analytical solutions.

关键词： VOF method shallow water waves wave evolution wave runup

IMPROVED DEM-CFD MODEL AND VALIDATION:A CONICAL-BASE SPOUTED BED SIMULATION STUDY

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Journal of Hydrodynamics 2010年第3期22卷 351-359页

作者： RONG Liang-wan ZHAN Jie-min Department of Applied Mechanics and engineering Sun Yat-sen University Guangzhou 510275 China Department of Applied Mechanics and engineering Sun Yat-sen University Guangzhou 510275 China guangdong province key laboratory of coastal ocean engineering Sun Yat-sen University Guangzhou 510275China

An improved and efficient DEM-CFD approach is developed for spouted beds. A nonlinear Discrete Element Method （DEM）, with a concept of spring, dash-pot and friction slider, is used for tracing the movement of each individual particle. The gas flow is described by a set of reorganized governing equations. Two phases are coupled through contributions due to effects of porosity, viscosity and drag. All equations are solved with the commercial package Fluent with an implementation of User Defined Functions （UDF）. To validate the improved model, a two-dimensional conical-base spouted bed is chosen as a case study. An unstructured mesh system is adopted instead of regular grid system. The simulation also takes the Saffman force and Magnus effect into account. The calculation results show good agreement with the experimental observations which are taken from the literature.

关键词： Discrete Element Method (DEM) spouted bed Fluent User Defined Functions (UDF) unstructured mesh

The reflection of regular and irregular waves by a partially perforated caisson breakwater on a step bed

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Acta oceanologica Sinica 2009年第4期28卷 107-117页

作者： LIU Yong LIYucheng TENG Bin XIA Zhisheng key laboratory of ocean engineering ocean University of china Qingdao 266100 China State key laboratory of coastal and Offshore engineering Dalian University of Technology Dalian 116024 China key laboratory of Water ＆ Water ＆ Sediment Science and Water Hazard Prevention Changsha 410076 China

This study examines the reflection of regular and irregular waves from a partially perforated caisson breakwater located on a step bed. The step bed is treated as an idealized rubble mound foundation. Based on the linear potential theory, an analytical solution is developed to calculate the reflection coefficient of the structure subjected to regular waves. The matched eigenfunction expansion method is used for the solution. The regular wave method is also extended to irregular waves using a linear transfer function. The calculated results obtained for limiting cases are exactly the same as corresponding results given by the previous researchers. The present predictions also agree well with experimental data in the published literatures. Numerical experiments are conducted to examine the variations of the reflection coefficient versus its main effect factors, and some interesting results are presented.

关键词： partially perforated caisson step irregular waves reflection coefficient

SENSITIVITY STUDY OF THE EFFECTS OF WAVE-INDUCED VERTICAL MIXING ON VERTICAL EXCHANGE PROCESSES

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Journal of Hydrodynamics 2010年第3期22卷 410-418页

作者： LIANG Bing-chen LEE Dong-yong LI Hua-jun ZHANG Jing key laboratory of ocean engineering Shandong Province Ocean University of China Qingdao 266100 China coastal and Harbour engineering Research Center Korea Ocean Research and Development Institute AnsanKorea College of engineering Ocean University of China Qingdao 266100 China

The hydrodynamic model COHERENS-SED, developed by the present authors through introducing wave-enhanced bottom stress, wave dependent surface drag coefficient, wave-induced surface mixing, SWAN to COHERENS, is modified to account for wave-induced vertical mixing. The COHERENS-SED model can also be used for one-dimensional, two-dimensional, three-dimensional current and salinity calculations. One-dimensional model and three-dimensional model are used to study the effects of the wave-induced vertical mixing. The horizontal current velocity profiles obtained by the model are in good agreement with the analytical velocity profiles under the same input conditions. Numerical results show that higher wave height would generally generate larger vertical eddy viscosity and lower horizontal velocity. The results for fresh water in Yellow River Delta show that the wave-induced vertical mixing increases the momentum of fresh water transferring ability downwards to seabed and salt water＇s mixing with upper fresh water. Fresh water flume length is compressed considerably.

关键词： Yellow River Delta COHERENS SWAN COHERENS-SED wave-induced vertical mixing

An Improved Finite Difference Scheme for Solving the Equation of Filtration Type in Porous Textiles with Phase Change Materials

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An Improved Finite Difference Scheme for Solving the Equatio...

Development of an integrated model system to simulate transport and fate of oil spills in seas

2007国际计算力学研讨会

作者： Q.Y.Zhu~(1 2*) 1 ocean engineering Research Center School of engineering Zhongshan University Guangzhou 510275 china 2.guangdong province key laboratory of coastal ocean engineering Zhongshan University Guangzhou 510275 china ocean engineering Research Center School of EngineeringZhongshan UniversityGuangzhou510275China guangdong province key laboratory of coastal ocean engineering Zhongshan University Guangzhou 510275 China

＜正＞In this paper an improved finite difference scheme is investigated to solve the equation of filtration type in porous textiles with phase change materials（PCM）,which can be expressed as a nonlinear source term. Due to the effects of source term,the constructed scheme is total variation bounded（TVB）.On the basis of this scheme thermal buffering effect of PCM is *** distributions of the temperature,saturated degree in the porous media with PCM were numerically computed by this *** the comparison the distributions of the temperature,saturated degree in the porous media without PCM were also numerically *** results indicate that this method is satisfactory.

关键词： improved finite difference scheme porous textiles phase change material

来源： cnki会议评论

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Science china(Technological Sciences) 2010年第11期53卷 2423-2434页

作者： WANG JinHua & SHEN YongMing State key laboratory of coastal and Offshore engineering,Dalian University of Technology,Dalian 116023,china State key laboratory of coastal and Offshore engineering Dalian University of Technology

A three-dimensional integrated model is developed for simulating transport and final fate of oil spills in *** model contains two main modules,flow and transport-fate *** flow module uses an unstructured finite-volume wave-ocean coupling *** unstructured meshes provides great flexibility for modeling the flow in complex geometries of tidal creeks,barriers and *** the transport-fate module the oil dispersion is solved using a particle-tracking *** diffusion is simulated using random walk techniques in a Monte Carlo framework,whereas the vertical diffusion process is solved on the basis of the Langeven *** model simulates the most significant processes that affect the motion of oil particles,such as advection,surface spreading,evaporation,dissolution,emulsification and turbulent diffusion as well as the interaction of the oil particles with the shoreline,sedimentation and the temporal variations of oil viscosity,density and surface *** model simulates either continuous or instantaneous oil spills,and also other toxic *** model has been applied to simulate the oil spill accident in the Bohai *** comparison with the observations,the numerical results indicate that the model is reasonably accurate.

关键词： oil-spill modeling finite-volume method oil particles 3-D unstructured grid

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The theoretical study on diagonal wave interaction with perforated-wall breakwater with rock fill

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Acta oceanologica Sinica 2009年第6期28卷 103-110页

作者： LIU Hongjie LIU Yong LI Yucheng Zhejiang Provincial Planning Design ＆ Research Institute of Communications Hangzhou 310006 China College of engineering Ocean University of China Qingdao 266100 China State key laboratory of coastal and Offshore engineering Dalian University of Technology Dalian 116023 China

The interaction of diagonal waves with perforated-wall breakwater partially filled with rock fill is studied using the linear potential theory. By means of the matched eigenfunction expansion method, an analytical method is presented to calculate the reflection coefficient and the wave force coefficient of the breakwater. The calculated results of the reflection coefficient for limiting cases are the same to the existing results. The main effect factors of the reflection coefficient and the wave force coefficient are analyzed by numerical examples. With the increasing of thickness of rock fill, the wave force coefficient on the perforated wall generally decreases, while the reflection coefficient increases. With the increasing of the incident angle of the wave, the reflection coefficient of the breakwater first decreases, reaches its minimum, and then increases monotonously.

关键词： diagonal wave perforated wall rock fill reflection coefficient wave force

A three dimensional k-ε-Ap model for water-sediment movement

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International Journal of Sediment Research 2010年第1期25卷 17-27页

作者： LIU Cheng1 and SHEN Yong-Ming2 1Ph.D.,Pearl River Hydraulic Research Institute,Guangzhou,510611,china 2Prof.,State key laboratory of coastal and Offshore engineering,Dalian University of Technology,Dalian 116024,china Ph.D. Pearl River Hydraulic Research Institute Guangzhou 510611 China Prof. State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

A three-dimensional k-ε-Ap two-fluid turbulence model is proposed to study liquid-particle two-phase flow and bed deformation. By solving coupled liquid-phase and solid-phase governing equations in a finite-volume method, the model can calculate the movement of both water and sediment. The model was validated by water-sediment transport in a 180° channel bend with a movable bed. The validation concerns two-phase time-averaged velocities, bed deformation, water depth, depth-averaged streamwise velocity, cross-stream bed profiles, and two-phase secondary flow velocity vectors. The agreement between numerical results and experimental results was generally good. The comparisons of the numerical results of different models show that the three-dimensional k-ε-Ap two-fluid turbulence model has a relatively higher accuracy than one-fluid model.

关键词： Three dimensional k-ε-Ap model Liquid-particle flow Two-fluid model Channel bend Bed deformation Curvilinear coordinates

Atmospheric correction of HJ-1A/B CCD images over Chinese coastal waters using MODIS-Terra aerosol data

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Science china(Technological Sciences) 2010年第S1期53卷 191-195页

作者： TIAN LiQiao 1,LU JianZhong 1,CHEN XiaoLing 1,2,3,YU ZhiFeng 1,XIAO JingJing 1,QIU Feng 1 & ZHAO Xi 1 1 State key laboratory of Information engineering in Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan 430079,china 2key laboratory of Poyang Lake Wetland and Watershed Research,Ministry of Education,Jiangxi Normal University,Nanchang 330022,china 3 The key laboratory of Poyang Lake Environment and Resource Utilization,Ministry of Education,Nanchang University,Nanchang 330031,china State key laboratory of Information engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan China key laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education Jiangxi Normal University Nanchang China The key laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China

This paper demonstrates an atmospheric correction method to process HJ-1A/B CCD images over Chinese coastal waters with the aid of MODIS-Terra aerosol *** on the assumption of zero water-leaving radiance at the two near-infrared (NIR)bands or the shortwave infrared(SWIR)bands,the atmospheric aerosol optical depth(AOD)is firstly retrieved from MODIS-Terra with a simple extension of the NIR-SWIR combined atmospheric correction approach embedded in SeaDAS (SeaWiFS data analysis system).Then the"turbid"and"non-turbid"waters are separated by the turbid water *** probability of AOD at 551 nm band is derived based on the NIR information over"non-turbid"waters and FLAASH model is selected to do the atmospheric correction of the HJ-1A/B CCD imagery using the AOD values of highest probabilities as ***,according to the histogram of the AOD distribution at 551 nm band,the studied turbid water area is divided into several blocks and HJ-1A/B CCD imagery is corrected with the corresponding AOD values displayed with the highest frequency in each *** method has been applied to several HJ-1A/B images over Chinese coastal waters and validated by synchronous in-situ *** results have shown that this method is effective in the atmospheric correction process of HJ-1A/B CCD images for ocean color remote sensing study and application in the coastal waters.

关键词： ocean color remote sensing atmospheric correction turbid coastal waters HJ-1A/B MODIS