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Post-stack reverse-time migration using a finite difference method based on triangular grids 认领 引用 被引量：8
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作者 郭书娟 李振春 +3 位作者 孙小东 叶月明 滕厚华 李芳 《Applied Geophysics》 SCIE 2008年第2期115-120,共6页
Compared with other migration methods, reverse-time migration is based on a precise wave equation, not an approximation, and performs extrapolation in the depth domain rather than the time domain. It is highly accurat... Compared with other migration methods, reverse-time migration is based on a precise wave equation, not an approximation, and performs extrapolation in the depth domain rather than the time domain. It is highly accurate and not affected by strong subsurface structure complexity and horizontal velocity variations. The difference method based on triangular grids maintains the simplicity of the difference method and the precision of the finite element method. It can be used directly for forward modeling on models with complex top surfaces and migration without statics preprocessing. We apply a finite difference method based on triangular grids for post-stack reverse-time migration for the first time. Tests on model data verify that the combination of the two methods can achieve near-perfect results in application. 展开更多
关键词 reverse-time migration structural complexity triangular grids finite difference
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An explicit finite volume element method for solving characteristic level set equation on triangular grids 认领 引用 被引量：1
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作者 Sutthisak Phongthanapanich Pramote Dechaumphai 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第6期911-921,共11页
Level set methods are widely used for predicting evolutions of complex free surface topologies,such as the crystal and crack growth,bubbles and droplets deformation,spilling and breaking waves,and two-phase flow pheno... Level set methods are widely used for predicting evolutions of complex free surface topologies,such as the crystal and crack growth,bubbles and droplets deformation,spilling and breaking waves,and two-phase flow phenomena.This paper presents a characteristic level set equation which is derived from the two-dimensional level set equation by using the characteristic-based scheme.An explicit finite volume element method is developed to discretize the equation on triangular grids.Several examples are presented to demonstrate the performance of the proposed method for calculating interface evolutions in time.The proposed level set method is also coupled with the Navier-Stokes equations for two-phase immiscible incompressible flow analysis with surface tension.The Rayleigh-Taylor instability problem is used to test and evaluate the effectiveness of the proposed scheme. 展开更多
关键词 Keywords Characteristic level set equation - Finite volume element method Explicit method Triangular grid Twophase incompressible flow
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A Finite Volume Method with Unstructured Triangular Grids for Numerical Modeling of Tidal Current 认领 引用 被引量：3
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作者 史宏达 刘臻 《China Ocean Engineering》 SCIE EI 2005年第4期693-700,共8页
The finite volume method （FVM） has many advantages in 2-D shallow water numerical simulation. In this study, the finite volume method is used with unstructured triangular grids to simulate the tidal currents. The Ro... The finite volume method （FVM） has many advantages in 2-D shallow water numerical simulation. In this study, the finite volume method is used with unstructured triangular grids to simulate the tidal currents. The Roe scheme is applied in the calculation of the intercell numerical flux, and the MUSCL method is introduced to improve its accuracy. The time integral is a two-step scheme of forecast and revision. For the verification of the present method, the Stoker＇s problem is calculated and the result is compared with the mathematically analytic solutions. The comparison indicates that the method is feasible. A sea area of a port is used as an example to test the method established here. The result shows that the present computational method is satisfactory, and it could be applied to the engineering fields. 展开更多
关键词 finite volume method numerical modeling unstructured triangular grids tidal currents
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THE EARLY INFLUENCE OF PETER LAX ON COMPUTATIONAL HYDRODYNAMICS AND AN APPLICATION OF LAX-FRIEDRICHS AND LAX-WENDROFF ON TRIANGULAR GRIDS IN LAGRANGIAN COORDINATES 认领 引用
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作者 Richard Liska Mikhail Shashkov Burton Wendroff 《Acta Mathematica Scientia》 SCIE CSCD 2011年第6期2195-2202,共8页
We give a brief discussion of some of the contributions of Peter Lax to Com- putational Fluid Dynamics. These include the Lax-Friedrichs and Lax-Wendroff numerical schemes. We also mention his collaboration in the 198... We give a brief discussion of some of the contributions of Peter Lax to Com- putational Fluid Dynamics. These include the Lax-Friedrichs and Lax-Wendroff numerical schemes. We also mention his collaboration in the 1983 HLL Riemann solver. We de- velop two-dimensional Lax-Friedrichs and Lax-Wendroff schemes for the Lagrangian form of the Euler equations on triangular grids. We apply a composite scheme that uses a Lax- Friedrichs time step as a dissipative filter after several Lax-Wendroff time steps. Numerical results for Noh＇s infinite strength shock problem, the Sedov blast wave problem, and the Saltzman piston problem are presented. 展开更多
关键词 Lax-Friedrichs Lax-Wendroff conservation laws Lagrangian coordinates,triangular grid
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A NEW DISPLACEMENT-TYPE STABILITY EQUATION AND GENERAL STABILITY ANALYSIS OF LAMINATED COMPOSITE CIRCULAR CONICAL SHELLS WITH TRIANGULAR GRID STIFFENERS 认领 引用
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作者 王虎 王俊奎 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1991年第4期383-392,共10页
In this paper, based on the theory of Donnell-type shallow shell, a new displacement-type stability equations is first developed for laminated composite circular conical shells with triangular grid stiffeners by using... In this paper, based on the theory of Donnell-type shallow shell, a new displacement-type stability equations is first developed for laminated composite circular conical shells with triangular grid stiffeners by using the variational calculus and generalized smeared-stiffener theory. The most general bending stretching couplings, the effect of eccentricity of stiffeners are considered. Then, for general stability of composite triangular grid stiffened conical shells without twist coupling terms, the approximate formulas are obtained for critical external pressure by using Galerkin's procedure. Numerical examples for a certain C/E composite conical shells with inside triangular grid stiffeners are calculated and the results are in good agreement with the experimental data. Finally, the influence of some parameters on critical external pressure is studied. The stability equations developed and the formulas for critical external pressure obtained in this paper should be very useful in the astronautical engineering design. 展开更多
关键词 general stability composite materials circular conical shells triangular grid stiffeners Galerkin's procedure
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Image interpolation algorithm on a triangular grid 认领 引用
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作者 Xu Lan Li Xuemei +1 位作者 Wang Guizhong Tian Shuo 《Computer Aided Drafting,Design and Manufacturing》 2016年第1期19-25,共7页
A new method for constructing a fitting surface on a triangular grid is presented. Assuming images are obtained by sampling from the original scene. Conventional polynomial interpolation methods generally construct th... A new method for constructing a fitting surface on a triangular grid is presented. Assuming images are obtained by sampling from the original scene. Conventional polynomial interpolation methods generally construct the fitting surface on a square grid. Different from existing methods, the new method constructs the fitting surface on a triangular grid which can divide the original surface more detailed and improve approximation accuracy. As the quality of the image edges plays a key role in visual effects of image, the new method uses image edges as constraints to get a triangle grid. The new method constructs a cubic polynomial patch locally using image data to approximate the original surface. Experimental comparison results of the new method with other methods show that the new method can produce high-quality images and remove the zigzagging artifact. 展开更多
关键词 surface fitting cubic polynomial triangular grid image edge
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An automatic isotropic/anisotropic hybrid grid generation technique for viscous flow simulations based on an artificial neural network 认领 引用 被引量：6
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作者 Peng LU Nianhua WANG +2 位作者 Xinghua CHANG Laiping ZHANG Yadong WU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2022年第4期102-117,共16页
Based on the author’s previous research, a novel hybrid grid generation technique is developed by introducing an Artificial Neural Network(ANN) approach for realistic viscous flow simulations. An initial hybrid grid ... Based on the author’s previous research, a novel hybrid grid generation technique is developed by introducing an Artificial Neural Network(ANN) approach for realistic viscous flow simulations. An initial hybrid grid over a typical geometry with anisotropic quadrilaterals in the boundary layer and isotropic triangles in the off-body region is generated by the classical mesh generation method to train two ANNs on how to predict the advancing direction of the new point and to control the grid size. After inputting the initial discretized fronts, the ANN-based Advancing Layer Method(ALM) is adopted to generate the anisotropic quadrilaterals in boundary layers. When the high aspect ratio of the anisotropic grid reaches a specified value, the ANN-based Advancing Front Method(AFM) is adopted to generate isotropic triangles in the off-body computational domain.The initial isotropic triangles are smoothed to further improve the grid quality. Three typical cases are tested and compared with experimental data to validate the effectiveness of grids generated by the ANN-based hybrid grid generation method. The experimental results show that the two ANNs can predict the advancing direction and the grid size very well, and improve the adaptability of the isotropic/anisotropic hybrid grid generation for viscous flow simulations. 展开更多
关键词 Advancing front method Advancing layer method Anisotropic quadrilateral grid generation Artificial neural network Isotropic triangular grid generation Machine learning
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渤海湾盆地辽河坳陷S1612块XⅡ稠油油藏三维地质建模 认领 引用
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作者 王伟刚 杨勇 《石油化工应用》 CAS 2026年第3期68-76,共9页
研究目的层位因为井位分布呈现出不均衡态势,运用传统地质参数平均取值方法所计算得出的地质储量,难以精准地反映出油藏的非均质性特征。为进一步提升储量评价的精确程度,本文针对角点网格与三角网格、确定性建模与随机建模等不同的建... 研究目的层位因为井位分布呈现出不均衡态势,运用传统地质参数平均取值方法所计算得出的地质储量,难以精准地反映出油藏的非均质性特征。为进一步提升储量评价的精确程度,本文针对角点网格与三角网格、确定性建模与随机建模等不同的建模方法展开对比分析,进而构建了三维地质模型,并在此基础上开展地质储量的计算工作。研究结果显示:(1)在模型精度相同的条件下,基于角点网格与三角网格构建的构造模型,其体积误差低于1%,这表明二者在几何形态上具备较高的一致性;(2)变差函数的变程对于油层在空间中的连续性具有显著的控制作用,然而,变程的增大并不必然会致使储量随之同步增加;(3)通过将稠油油层相模型与油水界面几何模型进行相交处理所获得的净毛比模型,能够较为理想地反映出实际稠油在空间中的分布特征,具备良好的一致性与合理性;(4)基于三维地质模型计算得到的地质储量低于传统碾平法的计算结果,主要原因在于前者能够更为真实地描绘出油层在三维空间中的非均质展布特性。综上所述,综合运用变差函数分析与随机建模技术,能够有效地对稠油油藏资源分布的非均质性进行表征。本研究成果可为复杂断块油藏的储量评估提供坚实的理论依据以及有力的技术支持,在相关领域具有广阔的应用前景以及重要的实践指导意义。 展开更多
关键词 角点网格 三角网格 确定性建模 随机建模 变差函数
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融合全球离散格网和元胞自动机的水体污染扩散模拟 认领 引用
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作者 孙永康 王金鑫 程相凯 《地球信息科学学报》 EI CAS CSCD 北大核心 2026年第4期942-956,共15页
【意义】地表过程的动力学模拟,对于理解和把握地理过程的演变规律及其对生态环境的影响意义重大,一直是地理信息科学领域研究的重点和难点。【背景】已有的研究偏重表面二维模拟,三维过程动态模拟亟待加强。全球离散格网系统(Discrete ... 【意义】地表过程的动力学模拟,对于理解和把握地理过程的演变规律及其对生态环境的影响意义重大,一直是地理信息科学领域研究的重点和难点。【背景】已有的研究偏重表面二维模拟,三维过程动态模拟亟待加强。全球离散格网系统(Discrete Global Grid Systems,DGGs)和元胞自动机(Cellular Automata,CA)的有机融合为地理过程的动态模拟提供了有力的工具和平台。【方法】以球体测地线八叉树格网(Sphere Geodesic Octree Grid,SGOG)构建鄂陵湖水体模拟平台,依据菲克第一定律原理,并基于C++语言、OSG(Open Scene Graph)三维引擎和集成开发平台,构建水体污染扩散可视化模型。分析和设计基于三角形元胞的二维、三维元胞邻居和转换规则,通过扩展虚拟元胞的方式设置湖泊堤岸处的边界条件,进行二维、三维以及基于岸边地形约束的静态污染扩散模拟实验,直观展示突发水体污染事件中污染物的二维和三维扩散过程,并对扩散模拟结果进行分析。【结果】①在污染限、瞬时投入的污染物总量相同并且考虑二维模拟和三维模拟中单个元胞所代表的实际水体空间不同时,三维模拟中高污染浓度元胞存在持续时间明显高于二维模拟,三维模拟中高污染浓度元胞持续时间相对二维模拟增长了55 min。且所涉及的元胞总量和实际水体空间也有显著差别:以扩散55 min时为例,二维模拟污染元胞总量为661个,而在三维模拟中污染元胞总量为3546个,此时三维模拟中污染所涉水体空间约为二维模拟结果的89.4%;②二维和三维模拟中,不同污染程度元胞占比的变化趋势较为接近,例如重度污染区域占比均在扩散前33 min降低至10%以下,轻度污染区域占比均在前33 min达到70%以上。但污染元胞在垂向上的空间分布不容忽视,三维模拟结果更符合污染扩散实际情况。【结论】本研究为水环境污染研究提供新的技术思路,同时为突发水体污染事件的管控提供决策参考。 展开更多
关键词 全球离散格网系统 球体大圆弧QTM八叉树格网 元胞自动机 三角形元胞 水体污染 扩散过程 三维动态模拟 可视化
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Triangular Curved Surface Construction of A Series ofArbitrary Disordered Points in Space 认领 引用
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作者 Wei Xiaopeng He Xin 《Computer Aided Drafting,Design and Manufacturing》 1998年第2期66-74,共9页
Constructing Bernstein-Bezier triangular interpolating curve surface interpolating a series of arbitrary disordered data points is of considerable importance for the design and modeling of surfaces with a variety of c... Constructing Bernstein-Bezier triangular interpolating curve surface interpolating a series of arbitrary disordered data points is of considerable importance for the design and modeling of surfaces with a variety of continuity information. In this article. a kind of simple and reliable algorithm that can process complex field triangular grid generating is presented, and a group of formulae for determining triangular curved surface with wholly C1 continuity are given. It can process arbitrary non-convex boundary and can be used to construct surfaces inner holes. 展开更多
关键词 geometric design and modeling scattered data interpolation. Bezier method triangular grid dividing.
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一种三角栅格排布的小型相控阵波控系统设计 认领 引用 被引量：1
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作者 徐波 石中立 《电子技术应用》 2025年第8期126-131,共6页
L频段因受雨衰等环境影响小、收发组件技术成熟以及制造成本低等优点而被海事卫通相控阵天线广泛采用。随着机载卫通天线不断朝小型化和低剖面方向发展,对相控阵天线的设计改进则提出了更高的挑战。在满足符合ARINC-781-8指标性能的前提... L频段因受雨衰等环境影响小、收发组件技术成熟以及制造成本低等优点而被海事卫通相控阵天线广泛采用。随着机载卫通天线不断朝小型化和低剖面方向发展,对相控阵天线的设计改进则提出了更高的挑战。在满足符合ARINC-781-8指标性能的前提下,相对矩形栅格排布,三角栅格排布因其布阵紧凑,可有效抑制栅瓣从而提高相控阵扫描性能;同时该排布结构所需天线单元数更少,更容易实现天线终端的小型化和低成本设计。以某L频段2×6三角栅格排布海事卫通相控阵天线为设计对象,对三角栅格排布结构的关键数学模型进行建模,介绍了该型天线的研制方法,设计了适用于该天线终端的波束扫描控制算法并在FPGA上进行了实现。天线实物样机随通信终端在室外环境下进行了静态实验,该实物样机可与海事卫星系统实现稳定通信,通信质量优良。 展开更多
关键词 L频段相控阵天线 海事卫星通信 波束扫描控制 三角栅格排布架构 相控阵小型化设计
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射线追踪模型算法对比及其应用 认领 引用 被引量：1
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作者 车晨 马力鹏 《电信工程技术与标准化》 2025年第6期47-51,67,共5页
本文研究了在无线信号传播预测中常用的两种射线追踪方法,即均匀矩形网格方法和三角网格方法,旨在为高效研发无线传播模型提供参考。本文详细探讨了每种方法的工作原理和具体实现步骤,并对二者的特点进行了简单对比。均匀矩形网格方法... 本文研究了在无线信号传播预测中常用的两种射线追踪方法,即均匀矩形网格方法和三角网格方法,旨在为高效研发无线传播模型提供参考。本文详细探讨了每种方法的工作原理和具体实现步骤,并对二者的特点进行了简单对比。均匀矩形网格方法将环境划分为简单的矩形网格单元,适用于大范围快速的传播预测;而三角网格方法则通过精确的几何建模和更贴近真实的路径追踪,能够提供更高的仿真精度,适合于复杂的行业专网环境。最后,提出了未来研究的可能方向,包括多级分区方法、神经网络与射线追踪结合以及基于GPU加速的实时模拟,以期进一步提升无线信号传播预测的精度和效率。 展开更多
关键词 射线追踪 无线信号传播预测 网络仿真 均匀矩形网格 三角网格
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Ray tracing of turning wave in elliptically anisotropic media with an irregular surface 认领 引用 被引量：2
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作者 Minghui Zhang Tao Xu +3 位作者 Zhiming Bai Youshan Liu Jue Hou Guiping Yu 《Earthquake Science》 CSCD 2017年第5期219-228,共10页
Seismic ray tracing in anisotropic media with irregular surface is crucial for the exploration of the fine crustal structure. Elliptically anisotropic medium is the type of anisotropic media with only four independent... Seismic ray tracing in anisotropic media with irregular surface is crucial for the exploration of the fine crustal structure. Elliptically anisotropic medium is the type of anisotropic media with only four independent elastic parameters. Usually, this medium can be described by only the vertical phase velocity and the horizontal phase velocity for seismic wave propagation. Model parameteri- zation in this study is described by flexible triangular grids, which is beneficial for the description of irregular surface with high degree of approximation. Both the vertical and horizontal phase velocities are defined in the triangular grids, respectively, which are used for the description of phase velocity distribution everywhere in the model by linear interpolation. We develop a shooting ray tracing method of turning wave in the elliptically anisotropic media with irregular surface. Runge-Kutta method is applied to solve the partial differential equation of seismic ray in elliptically anisotropic media. Linearly modified method is used for adjusting emergent phase angles in the shooting scheme. Numerical tests demonstrate that ray paths coincide well with analytical trajectories in trans- versely homogeneous elliptically anisotropic media. Seis- mic ray tracing results in transversely inhomogeneous elliptically anisotropic media demonstrate that our method is effective for further first-arrival tomography in ellipti- cally anisotropic media with an irregular surface. 展开更多
关键词 Ray tracing Elliptically anisotropic media Vertical and horizontal phase velocity Irregular surface Triangular grids
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An Application of Finite Volume WENO Schemeto Numerical Modeling of Tidal Current 认领 引用 被引量：2
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作者 杨中华 槐文信 曾小辉 《China Ocean Engineering》 SCIE EI 2006年第4期545-556,共12页
A depth-averaged 2-D numerical model for unsteady tidal flow in estuaries is established by use of the finite volume WENO scheme which maintains both uniform high order accuracy and an essentially non-oscillatory shoc... A depth-averaged 2-D numerical model for unsteady tidal flow in estuaries is established by use of the finite volume WENO scheme which maintains both uniform high order accuracy and an essentially non-oscillatory shock transition on unstructured triangular grid. The third order TVD Range-Kutta method is used for time discretization. The model has been firstly tested against four cases： 1） tidal forcing, 2） seiche oscillation, 3） wind setup in a closed bay, and 4） onedimensional dam-break water flow. The results obtained in the present study compare well with those obtained from the corresponding analytic solutions idealized for the above four cases. The model is then applied to the simulation of tidal circulation in the Yangpu Bay, and detailed model calibration and verification have been conducted with measured tidal current in the spring tide, middle tide, and neap tide. The overall performance of the model is in qualitative agreement with the data observed in 2005, and it can be used to calculate the flow in estuaries and coastal waters. 展开更多
关键词 tidal current numerical modeling WENO scheme unstructured triangular grid
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Three-dimensional tidal current numerical model of the Oujiang Estuary 认领 引用 被引量：2
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作者 LI Mengguo LI Wendan 《Acta Oceanologica Sinica》 SCIE CAS 2009年第3期17-25,共9页
The characteristics of three-dimensional(3-D)tidal current in the Oujiang Estuary are investigated according to in situ observations.The Oujiang Estuary has features of irregular coastline,complex topography,many isla... The characteristics of three-dimensional(3-D)tidal current in the Oujiang Estuary are investigated according to in situ observations.The Oujiang Estuary has features of irregular coastline,complex topography,many islands,moveable boundary,and submerged dyke,therefore,σ3-D numerical model oil an unstructured triangular grid has been degeloped.Theσcoordinate transforination,the moveable boundary and submerged dyke treatment techniques were employed in the model so it is suitable for the tidal simulations in the Oujing Estuary with submerged dyke and moveable boundary problems.The model is evaluated with the in situ data,and the results show that the calculated water elevations at 19 stations and currents at 19 profiler stations are in good agreement with measured data both in magnitude and phase.This numerical model is applied to the 3-D tidal circulation simulations of experiments in stopping flow transport through the South Branch of the Oujiang Estuary,and the feasibility to cutoff the flow in the South Branch of the Oujiang Estuary is demonstrated by numerical simulation experiments.The developed numerical model simulated the 3-D tidal current circulations in complicated coastal and estuarine waters very well. 展开更多
关键词 Oujiang Estuary three-dimensional tidal current mathematical model numerical simulation triangular grid σcoordinate transformation
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Robust Falk-Neilan Finite Elements for the Reissner-Mindlin Plate 认领 引用 被引量：1
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作者 Shangyou Zhang 《Communications on Applied Mathematics and Computation》 2023年第4期1697-1712,共16页
The family of Falk-Neilan Pkfinite elements,combined with the Argyris Pk+1finite elements,solves the Reissner-Mindlin plate equation quasi-optimally and locking-free,on triangular meshes.The method is truly conf... The family of Falk-Neilan Pkfinite elements,combined with the Argyris Pk+1finite elements,solves the Reissner-Mindlin plate equation quasi-optimally and locking-free,on triangular meshes.The method is truly conforming or consistent in the sense that no projectioneduction is introduced.Theoretical proof and numerical confirmation are presented. 展开更多
关键词 Locking free Reissner-Mindlin equation Finite element Triangular grids
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点云数据下的矿山巷道三维建模 认领 引用 被引量：19
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作者 石信肖 王健 +2 位作者 王磊 李志远 付洪磊 《遥感信息》 CSCD 北大核心 2019年第6期99-104,共6页
基于三维激光扫描技术获取数据点云,对煤矿巷道进行精细三维建模。研究了狭长型海量巷道点云数据精细建模问题,使用Delaunay生长算法引入边、角等约束条件,设置不同三角网边长阈值对点云数据分析处理,在保证模型细节前提下选取合适的边... 基于三维激光扫描技术获取数据点云,对煤矿巷道进行精细三维建模。研究了狭长型海量巷道点云数据精细建模问题,使用Delaunay生长算法引入边、角等约束条件,设置不同三角网边长阈值对点云数据分析处理,在保证模型细节前提下选取合适的边长阈值完成巷道整体构网,实现了巷道实体对象的全景建模并对模型精度进行了分析。借助某煤矿点云数据验证了三维激光技术在巷道建模的可行性,为数字化矿山建设提供准确精细的数字化模型。 展开更多
关键词 点云 矿山 巷道 三角网 三维建模
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离散三角网格系统距离量测方法 认领 引用 被引量：8
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作者 袁文 庄大方 +2 位作者 袁武 唐志峰 邱冬生 《测绘学报》 EI CSCD 北大核心 2011年第1期59-65,共7页
根据离散三角网格系统的空间分布特征,构建新型的十二连通拓扑空间几何距离量测方法,根据三角网格的边的方向性差异性及空间分布格局特征提出一种新型的三角网格单元三维IJK坐标系统,给出该坐标系统与传统行列坐标系统的坐标转换方法,... 根据离散三角网格系统的空间分布特征,构建新型的十二连通拓扑空间几何距离量测方法,根据三角网格的边的方向性差异性及空间分布格局特征提出一种新型的三角网格单元三维IJK坐标系统,给出该坐标系统与传统行列坐标系统的坐标转换方法,推导三角网格系统的距离计算公式,为基于三角网格系统构建的柏拉图立体三角网格剖分系统的距离计算奠定了基础。 展开更多
关键词 离散三角网格 坐标系 坐标转换 距离量测
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全球离散格网系统结构要素一体化编码与生成方法 认领 引用 被引量：5
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作者 陈艺航 王金鑫 +2 位作者 曹泽宁 秦子龙 石焱 《地球信息科学学报》 EI CSCD 北大核心 2021年第8期1382-1390,共9页
全球离散格网系统是用于构建数字地球的一种有效空间数据组织框架,其中,三角形、四边形和六边形等多种单元形状的格网已在各领域广泛应用。各具特色的格网满足了各专业领域的应用需求,但也因其格网类型的差异而阻碍了跨领域的数据共享,... 全球离散格网系统是用于构建数字地球的一种有效空间数据组织框架,其中,三角形、四边形和六边形等多种单元形状的格网已在各领域广泛应用。各具特色的格网满足了各专业领域的应用需求,但也因其格网类型的差异而阻碍了跨领域的数据共享,同时单一格网在面向多领域科学问题上存在一定的局限性,因此实现多类型离散格网系统之间的互操作功能具有重要的研究意义。不同类型格网结构要素相互转换机制的建立,是实现异构格网数据集互操作的关键。本文针对这一问题,首先,研究了三类全球离散格网系统结构要素的统一特征及格点和格元的相互关系,进一步揭示了其等差圈层的分布模式;其次,以球面四元三角网为例,建立了格点的等差圈层编码,随后,根据格点与格元的关系提出了基于格点索引的全球离散格网一体化编码与生成方法;最后,利用该方法生成了河南省地表高程的格点模型、三角形格网模型、菱形格网模型和六边形格网模型,并验证了其正确性和可行性,为全球离散格网的互操作机制提供一种新思路。 展开更多
关键词 全球离散格网 格点 三角形格网 菱形格网 六边形格网 一体化编码 互操作
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非常规油气藏不规则复杂裂缝表征方法 认领 引用 被引量：6
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作者 何佑伟 谢义翔 +2 位作者 乔宇 陈玉林 汤勇 《石油实验地质》 CAS CSCD 北大核心 2024年第4期748-759,共12页
非常规油气资源储量大,开发难度高。储层压裂改造是非常规油气资源开发的关键技术手段。天然裂缝和压裂裂缝具有不规则性和复杂性。针对现有裂缝表征方法难以准确刻画裂缝真实形状和宽度变化等不规则特性这一问题,提出了基于非结构PEBI... 非常规油气资源储量大,开发难度高。储层压裂改造是非常规油气资源开发的关键技术手段。天然裂缝和压裂裂缝具有不规则性和复杂性。针对现有裂缝表征方法难以准确刻画裂缝真实形状和宽度变化等不规则特性这一问题,提出了基于非结构PEBI网格的不规则复杂裂缝表征方法。首先,建立基于PEBI网格的天然裂缝表征流程,实现对任意区域或限定区域天然裂缝的准确表征;其次,建立基于Delaunay三角形网格和PEBI网格的压裂裂缝表征及优化方法,分析网格尺寸及优化次数对裂缝表征精度的影响;第三,建立基于非结构网格的非平面裂缝表征方法,实现对弯曲裂缝的刻画和表征,裂缝形态和分布与实际情况更相符;第四,提出非均匀裂缝宽度表征方法,实现对变宽度即同一条裂缝宽度和导流能力不均匀分布裂缝的精细表征;第五,在全区域和限定区域内,实现耦合不规则压裂裂缝和不规则天然裂缝的复杂缝网表征。针对大规模天然裂缝与压裂裂缝相交、裂缝宽度非均匀分布、非平面裂缝等复杂条件下的裂缝网络表征,通过调整网格优化次数,能够提高缝网表征质量。利用PEBI网格能够灵活准确逼近裂缝复杂边界条件的优势,实现快速、准确地显示处理大量不规则天然裂缝和压裂裂缝。形成的不规则复杂裂缝表征方法,有助于提高非常规油气藏裂缝网络的表征精度和数值模拟计算准确性。 展开更多
关键词 非常规油气藏 不规则裂缝 复杂缝网 裂缝表征 Delaunay三角形网格 PEBI网格
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