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3D Electrical Resistance Tomography for Finite-Volume Targets Using Unstructured FEM and L-BFGS 认领 引用 被引量：1
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作者 Shi-jie Gao Han-dong Tan +3 位作者 Huan Ma Feng-qun Ma Jian-ping Wu Xiao Liu 《Applied Geophysics》 SCIE CSCD 2026年第2期467-484,864,865,共18页
To develop better non-destructive detection technology,we developed the Electrical Resistance Tomography(ERT)inverse algorithm research based on the L-BFGS method and implemented the ERT approach to detect the finite-... To develop better non-destructive detection technology,we developed the Electrical Resistance Tomography(ERT)inverse algorithm research based on the L-BFGS method and implemented the ERT approach to detect the finite-volume targets electrical structure in the construction engineering field and other fi elds.Initially,we compared the forward calculation results with Adam's forward calculation results,and,subsequently,we can see that the electric potential has recovered to a certain extent,indicating that the algorithm is eff ective.Next,the 3D inversion adopts the L-BFGS method based on unstructured grids.The L-BFGS inversion is a regularization inversion,which constrains the model space,adopts a new model smoothing strategy,derives the smoothness operator on the unstructured grid in the finite element,and introduces the L2 norm to define the smoothness of the model.The L-BFGS inversion method improves the inversion effect,which is mainly reflected in saving calculation space,accelerating calculation speed,and providing excellent imaging results.Furthermore,we used the MPI parallel algorithm to speed up the calculation.The accuracy of the algorithm is verifi ed by the inversions of several theoretical models.The ERT algorithm is employed to reconstruct the three-dimensional conductivity distribution within the targets object.Several experiments demonstrate that the ERT method can both locate and image steel bar in concrete,and demonstrate that it is possible to estimate the location of cracks or other insulators(e.g.the plastic plates)in concrete.Besides,the algorithm embodies the advantage that a fi nite-volume targets can be observed on any surface. 展开更多
关键词 ERT fi nite-volume targets unstructured fi nite element L-BFGS Non-destructive testing
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High-order finite-volume central targeted essentially non-oscillatory schemes for shock-driven flows on unstructured meshes 认领 引用
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作者 Qihang MA Feng FENG +1 位作者 Bofu WANG Quan ZHOU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2026年第5期1177-1204,共28页
The high-order targeted essentially non-oscillatory(TENO)scheme,known for its innovative weighting strategy,has demonstrated strong potential for complex flow predictions and applications.This study extends the TENO w... The high-order targeted essentially non-oscillatory(TENO)scheme,known for its innovative weighting strategy,has demonstrated strong potential for complex flow predictions and applications.This study extends the TENO weighting approach to develop a family of central TENO(CTENO)schemes for unstructured meshes.The CTENO schemes employ compact directional stencils,which increase the likelihood of finding all stencils within smooth regions.The design is intentionally compact to simplify the implementation of directional stencils.An effective scale-separation strategy is adopted via an essentially non-oscillatory(ENO)-like stencil selection method,which employs large central stencils in smooth areas to achieve high-order accuracy,and employs smaller directional stencils near discontinuities to improve shock-capturing capability.Extensive tests involving central weighted essentially non-oscillatory(CWENO),TENO,and CTENO family schemes are conducted to assess their performance in terms of accuracy,parallel scalability,and computational efficiency.The applications to shock-driven flows indicate that the proposed schemes deliver high-order accuracy,lower numerical dissipation,and excellent shock-capturing performance in several practical flow cases such as shock reflection,bubble dynamics,explosion,and particle flow problems. 展开更多
关键词 high order shock wave unstructured mesh compressible flow
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A novel unstructured-grid generator using upscaling applied to a compositional reservoir simulator 认领 引用
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作者 Marcelo Menezes Farias Pedro Salgueiro +3 位作者 Ivens da Costa Menezes Lima Francisco Marcondes Joaquim Bento Cavalcante-Neto Kamy Sepehrnoori 《Petroleum Science》 SCIE EI CAS CSCD 2026年第6期3439-3458,共20页
This work introduces a novel unstructured grid generator using an upscaling technique and the Element-based Finite Volume Method(EbFVM).The proposed grid generator can either replicate the original structured Corner P... This work introduces a novel unstructured grid generator using an upscaling technique and the Element-based Finite Volume Method(EbFVM).The proposed grid generator can either replicate the original structured Corner Point grid as an unstructured mesh or coarsen it by upscaling reservoir properties for computational efficiency.The proposed methodology enables flexible grid coarsening from structured geological models while preserving numerical accuracy in critical flow regions.The approach integrates a user-defined clustering algorithm with a Dykstra-Parsons coefficient to generate hybrid-resolution grids.A modified Cardwell-Parsons method is used for permeability upscaling and volumetric averaging for porosity.An unstructured grid option has been implemented into the UTCOMPRS simulator,and the grid generator is evaluated and validated through five case studies,including realistic reservoir models and industry benchmarks such as UNISIM-I,model 2 of the SPE10case,and the Sleipner CO2 storage project using the UTCOMPRS.Results demonstrate the approach's ability to significantly reduce computational costs while maintaining reliable production forecasts.This work presents a compelling and computationally efficient tool for reservoir simulation. 展开更多
关键词 Compositional reservoir simulation Upscaling Element-based Finite Volume Method Unstructured grids
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Large Language Model in Healthcare for the Prediction of Genetic Variants from Unstructured Text Medicine Data Using Natural Language Processing 认领 引用 被引量：1
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作者 Noor Ayesha Muhammad Mujahid +2 位作者 Abeer Rashad Mirdad Faten S.Alamri Amjad R.Khan 《Computers, Materials & Continua》 SCIE EI 2025年第7期1883-1899,共17页
Large language models(LLMs)and natural language processing(NLP)have significant promise to improve efficiency and refine healthcare decision-making and clinical results.Numerous domains,including healthcare,are rapidl... Large language models(LLMs)and natural language processing(NLP)have significant promise to improve efficiency and refine healthcare decision-making and clinical results.Numerous domains,including healthcare,are rapidly adopting LLMs for the classification of biomedical textual data in medical research.The LLM can derive insights from intricate,extensive,unstructured training data.Variants need to be accurately identified and classified to advance genetic research,provide individualized treatment,and assist physicians in making better choices.However,the sophisticated and perplexing language of medical reports is often beyond the capabilities of the devices we now utilize.Such an approach may result in incorrect diagnoses,which could affect a patient’s prognosis and course of therapy.This study evaluated the efficacy of the proposed model by looking at publicly accessible textual clinical data.We have cleaned the clinical textual data using various text preprocessing methods,including stemming,tokenization,and stop word removal.The important features are extracted using Bag of Words(BoW)and Term Frequency-Inverse Document Frequency(TFIDF)feature engineering methods.The important motive of this study is to predict the genetic variants based on the clinical evidence using a novel method with minimal error.According to the experimental results,the random forest model achieved 61%accuracy with 67%precision for class 9 using TFIDF features and 63%accuracy and a 73%F1 score for class 9 using Bag of Words features.The accuracy of the proposed BERT(Bidirectional Encoder Representations from Transformers)model was 70%with 5-fold cross-validation and 71%with 10-fold cross-validation.The research results provide a comprehensive overview of current LLM methods in healthcare,benefiting academics as well as professionals in the discipline. 展开更多
关键词 LLM unstructured data genetics prediction healthcare medicine
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Adaptive Vibration-Driven Tensegrity in Unstructured Environments 认领 引用
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作者 Ruhe Mei Ruizhi Liu +1 位作者 Yafeng Wang Xian Xu 《Journal of Bionic Engineering》 SCIE EI CSCD 2025年第5期2354-2366,共13页
Tensegrity structures,embodying the principles of continuous tensioning and discrete compression,have emerged as fundamental frameworks in locomotive soft robotics for navigating uneven and unpredictable environments,... Tensegrity structures,embodying the principles of continuous tensioning and discrete compression,have emerged as fundamental frameworks in locomotive soft robotics for navigating uneven and unpredictable environments,owing to their flexible and resilient traits.By means of a straightforward and cost-effective method to achieve structure-driven,vibration-driven tensegrity shows great potential,particularly in tasks demanding random exploration.However,the design guidance for vibration-driven tensegrity and their performance evaluation in unstructured terrain remain unrevealed due to the complex dynamics of the structure.This paper presents a small six-bar tensegrity robot,driven by wireless vibration motors,designed for deployment in disaster rescue and search scenarios.Finite element simulation is used to investigate how structural characteristics,excitation parameters,and the arrangement of motors affect the kinematic performance of this tensegrity system.A prototype of the six-bar tensegrity robot with three motors located on the lower ends of the three lower struts is designed and manufactured after the numerical simulations.A simple control policy which adjusts the motion of the tensegrity robot by turning on or off the motors on different locations is proposed.The prototype with and without the control policy is tested in man-made environments of various complexity.It shows that the ability and efficiency of the tensegrity robot in exploring unstructured environments is significantly enhanced by the proposed control policy.It is believed that the potential of the vibration-driven tensegrity robot could be further exploited by integrating multi-source sensors and more intelligent control policies. 展开更多
关键词 Finite element simulation Parametric design Tensegrity Unstructured environment Vibration
Vortex-Induced Vibration Prediction in Floating Structures via Unstructured CFD and Attention-Based Convolutional Modeling 认领 引用
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作者 Yan Li Yibin Wu Bo Zhang 《Fluid Dynamics & Materials Processing》 EI 2025年第12期2905-2925,共21页
Traditional Computational Fluid Dynamics(CFD)simulations are computationally expensive when applied to complex fluid–structure interaction problems and often struggle to capture the essential flow features governing ... Traditional Computational Fluid Dynamics(CFD)simulations are computationally expensive when applied to complex fluid–structure interaction problems and often struggle to capture the essential flow features governing vortex-induced vibrations(VIV)of floating structures.To overcome these limitations,this study develops a hybrid framework that integrates high-fidelity CFD modeling with deep learning techniques to enhance the accuracy and efficiency of VIV response prediction.First,an unstructured finite-volume fluid–structure coupling model is established to generate high-resolution flow field data and extract multi-component time-series feature tensors.These tensors serve as inputs to a Squeeze-and-Excitation Convolutional Neural Network(SE-CNN),which models the nonlinear coupling between flow disturbances and structural responses.The SE-CNN architecture incorporates an attention-based weighting mechanism through an embedded Squeeze-and-Excitation module,dynamically optimizing channel feature importance and improving sensitivity to critical flow characteristics.During training,multidimensional inputs,including pressure,velocity gradient,and displacement sequences,are used to capture the full complexity of fluid–structure interactions.Results demonstrate that the proposed method achieves a maximum amplitude prediction error of only 2.9%and a main frequency deviation below 0.03 Hz,outperforming conventional CNN models by reducing amplitude prediction error from 3.2%to 1.9%.The approach is validated using a representative semi-submersible platform,confirming its robustness across varying damping conditions and flow velocities. 展开更多
关键词 Unstructured grid computational fluid dynamics squeeze-and-excitation convolutional neural network vortex-induced vibration floating structure
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CFH-Net:Transformer-Based Unstructured Road-Free Space Detection Network 认领 引用
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作者 Jingcheng Yang Lili Fan Hongmei Liu 《Computers, Materials & Continua》 SCIE EI 2025年第6期4725-4740,共16页
With the advancement of deep learning in the automotive domain,more and more researchers are focusing on autonomous driving.Among these tasks,free space detection is particularly crucial.Currently,many model-based app... With the advancement of deep learning in the automotive domain,more and more researchers are focusing on autonomous driving.Among these tasks,free space detection is particularly crucial.Currently,many model-based approaches have achieved autonomous driving on well-structured urban roads,but these efforts primarily focus on urban road environments.In contrast,there are fewer deep learningmethods specifically designed for off-road traversable area detection,and their effectiveness is not yet satisfactory.This is because detecting traversable areas in complex outdoor environments poses significant challenges,and current methods often rely on single-image inputs,which do not align with contemporary multimodal approaches.Therefore,in this study,we propose a CFH-Net model for off-road traversable area detection.This model employs a Transformer architecture to enhance its capability of capturing global information.For multimodal feature extraction and fusion,we integrate the CM-FRM module for feature extraction and introduce the novel FFX module for feature fusion,thereby improving the perception capability of autonomous vehicles on unstructured roads.To address upsampling,we propose a new convolution precorrection method to reduce model parameters and computational complexity while enhancing the model’s ability to capture complex features.Finally,we conducted experiments on the ORFD off-road dataset and achieved outstanding results. 展开更多
关键词 Freespace detection semantic segmentation terrain perception unstructured environment
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3D magnetotelluric inversions with unstructured finite-element and limited-memory quasi-Newton methods 认领 引用 被引量：14
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作者 Cao Xiao-Yue Yin Chang-Chun +3 位作者 Zhang Bo Huang Xin Liu Yun-He Cai Jing 《Applied Geophysics》 SCIE CSCD 2018年第3期556-565,共10页
Traditional 3D Magnetotelluric(MT) forward modeling and inversions are mostly based on structured meshes that have limited accuracy when modeling undulating surfaces and arbitrary structures. By contrast, unstructured... Traditional 3D Magnetotelluric(MT) forward modeling and inversions are mostly based on structured meshes that have limited accuracy when modeling undulating surfaces and arbitrary structures. By contrast, unstructured-grid-based methods can model complex underground structures with high accuracy and overcome the defects of traditional methods, such as the high computational cost for improving model accuracy and the difficulty of inverting with topography. In this paper, we used the limited-memory quasi-Newton(L-BFGS) method with an unstructured finite-element grid to perform 3D MT inversions. This method avoids explicitly calculating Hessian matrices, which greatly reduces the memory requirements. After the first iteration, the approximate inverse Hessian matrix well approximates the true one, and the Newton step(set to 1) can meet the sufficient descent condition. Only one calculation of the objective function and its gradient are needed for each iteration, which greatly improves its computational efficiency. This approach is well-suited for large-scale 3D MT inversions. We have tested our algorithm on data with and without topography, and the results matched the real models well. We can recommend performing inversions based on an unstructured finite-element method and the L-BFGS method for situations with topography and complex underground structures. 展开更多
关键词 Magnetotelluric(MT) 3D inversion unstructured fi nite-element method quasi-Newton method L-BFGS
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Three-dimensional magnetotellurics modeling using edgebased finite-element unstructured meshes 认领 引用 被引量：19
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作者 刘长生 任政勇 +1 位作者 汤井田 严艳 《Applied Geophysics》 SCIE 2008年第3期170-180,共11页
Three-dimensional forward modeling magnetotellurics （MT） problems. We present a is a challenge for geometrically complex new edge-based finite-element algorithm using an unstructured mesh for accurately and efficien... Three-dimensional forward modeling magnetotellurics （MT） problems. We present a is a challenge for geometrically complex new edge-based finite-element algorithm using an unstructured mesh for accurately and efficiently simulating 3D MT responses. The electric field curl-curl equation in the frequency domain was used to deduce the H （curl） variation weak form of the MT forward problem, the Galerkin rule was used to derive a linear finite-element equation on the linear-edge tetrahedroid space, and, finally, a BI-CGSTAB solver was used to estimate the unknown electric fields. A local mesh refinement technique in the neighbor of the measuring MT stations was used to greatly improve the accuracies of the numerical solutions. Four synthetic models validated the powerful performance of our algorithms. We believe that our method will effectively contribute to processing more complex MT studies. 展开更多
关键词 Magnetotelluric modeling edge-based finite-element unstructured mesh local mesh refinement
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An Improved LU-SGS Implicit Scheme for High Reynolds Number Flow Computations on Hybrid Unstructured Mesh 认领 引用 被引量：11
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作者 WANG Gang JIANG Yuewen YE Zhengyin 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2012年第1期33-41,共9页
The lower-upper symmetric Gauss-Seidel （LU-SGS） implicit relaxation has been widely used because it has the merits of less dependency on grid topology, low numerical complexity and modest memory requirements. In ori... The lower-upper symmetric Gauss-Seidel （LU-SGS） implicit relaxation has been widely used because it has the merits of less dependency on grid topology, low numerical complexity and modest memory requirements. In original LU-SGS scheme, the implicit system matrix is constructed based on the splitting of convective flux Jacobian according to its spectral radius. Although this treatment has the merit of reducing computational complexity and helps to ensure the diagonally dominant property of the implicit system matrix, it can also cause serious distortions on the implicit system matrix because too many approximations are introduced by this splitting method if the contravariant velocity is small or close to sonic speed. To overcome this shortcoming, an improved LU-SGS scheme with a hybrid construction method for the implicit system matrix is developed in this paper. The hybrid way is that： on the cell faces having small contravariant velocity or transonic contravariant velocity, the accurate derivative of the convective flux term is used to construct more accurate implicit system matrix, while the original Jacobian splitting method is adopted on the other cell faces to reduce computational complexity and ensure the diagonally dominant property of the implicit system matrix. To investigate the convergence performance of the improved LU-SGS scheme, 2D and 3D turbulent flows around the NACA0012 airfoil, RAE2822 airfoil and LANN wing are simulated on hybrid unstructured meshes. The nu- merical results show that the improved LU-SGS scheme is significantly more efficient than the original LU-SGS scheme. 展开更多
关键词 LU-SGS scheme hybrid unstructured mesh Navier-Stokes equations flux Jacobian convergence performance turbulent flow
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CPG Modulates the Omnidirectional Motion of a Hexapod Robot in Unstructured Terrain 认领 引用 被引量：6
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作者 Wei Zhang Qingshuo Gong +1 位作者 Haoyu Yang Yejing Tang 《Journal of Bionic Engineering》 SCIE EI CSCD 2023年第2期558-567,共10页
Freely shuttling in complex terrain is a basic skill of multi-legged animals.To make the hexapod robot have omnidirectional motion ability by controlling only one parameter,this paper uses the motion control method ba... Freely shuttling in complex terrain is a basic skill of multi-legged animals.To make the hexapod robot have omnidirectional motion ability by controlling only one parameter,this paper uses the motion control method based on Central Pattern Generator(CPG),maps the output signal of CPG to the foot end trajectory space of the hexapod robot,and proposes an omnidirectional gait controller strategy.In addition,to enable the hexapod robot to adapt to unstructured terrain,an adaptive method based on Dynamic Threshold(DT)is proposed to enable the hexapod robot move in all directions without changing the heading angle in unstructured terrain.Finally,the feasibility of the proposed method is verified by virtual simulation and hexapod robot prototype experiment.Results show that the hexapod robot can omnidirectional motion without changing the heading angle and has good stability in unstructured terrain. 展开更多
关键词 Bionic Robot Central Pattern Generator(CPG) Omnidirectional Gait Unstructured Terrain
Hermite WENO-based limiters for high order discontinuous Galerkin method on unstructured grids 认领 引用 被引量：7
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作者 Zhen-Hua Jiang Chao Yan +1 位作者 Jian Yu Wu Yuan 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第2期241-252,共12页
A novel class of weighted essentially nonoscillatory （WENO） schemes based on Hermite polynomi- als, termed as HWENO schemes, is developed and applied as limiters for high order discontinuous Galerkin （DG） method o... A novel class of weighted essentially nonoscillatory （WENO） schemes based on Hermite polynomi- als, termed as HWENO schemes, is developed and applied as limiters for high order discontinuous Galerkin （DG） method on triangular grids. The developed HWENO methodology utilizes high-order derivative information to keep WENO re- construction stencils in the von Neumann neighborhood. A simple and efficient technique is also proposed to enhance the smoothness of the existing stencils, making higher-order scheme stable and simplifying the reconstruction process at the same time. The resulting HWENO-based limiters are as compact as the underlying DG schemes and therefore easy to implement. Numerical results for a wide range of flow conditions demonstrate that for DG schemes of up to fourth order of accuracy, the designed HWENO limiters can simul- taneously obtain uniform high order accuracy and sharp, es- sentially non-oscillatory shock transition. 展开更多
关键词 Discontinuous Galerkin method Limiters WENO. High order accuracy. Unstructured grids
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Three-dimensional forward modeling for the SBTEM method using an unstructured fi nite-element method 认领 引用 被引量：4
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作者 Wang Lu-Yuan Yin Chang-Chun +5 位作者 Liu Yun-He Su Yang Ren Xiu-Yan Hui Zhe-Jian Zhang Bo Xiong Bin 《Applied Geophysics》 SCIE CSCD 2021年第1期101-116,130,共16页
In this study,we propose a three-dimensional(3D)forward modeling algorithm of surface-to-borehole transient electromagnetic(SBTEM)fields based on an unstructured vector fi nite-element method to analyze the characteri... In this study,we propose a three-dimensional(3D)forward modeling algorithm of surface-to-borehole transient electromagnetic(SBTEM)fields based on an unstructured vector fi nite-element method to analyze the characteristics of SBTEM responses for complex geoelectrical models.To solve the double-curl diff usion equation for the electric fi eld,we use an unstructured tetrahedral mesh to discretize the model domain and select the unconditionally stable backward Euler scheme to discretize the time derivative.In our numerical experiments,we use a grounded wire as a transmitting source.After validating the algorithm’s eff ectiveness,we first analyze the diffusion characteristics and detectability of the electromagnetic field.After that,we focus our attention on the distribution and the cause of zero bands for Ex and dBy/dt components with the hope of guiding future field surveys.Finally,by simulating diff erent models,we analyze the capability of the SBTEM method in detecting typical mineral veins so that we can provide a reference for mineral resource exploration in the deep earth. 展开更多
关键词 Surface-to-borehole TEM forward modeling edge-based FE method unstructured grids zero bands
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Applications of multi-dimensional schemes on unstructured grids for high-accuracy heat flux prediction 认领 引用 被引量：4
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作者 Yunbo Wan Nianhua Wang +1 位作者 Laiping Zhang Yewei Gui 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2020年第1期57-71,共15页
The simulation of hypersonic flows with fully unstructured(tetrahedral)grids has severe problems with respect to the prediction of stagnation region heating,due to the random face orientation without alignment to the ... The simulation of hypersonic flows with fully unstructured(tetrahedral)grids has severe problems with respect to the prediction of stagnation region heating,due to the random face orientation without alignment to the bow shock.To improve the accuracy of aero-heating predictions,three multi-dimensional approaches on unstructured grids are coupled in our Reynolds-averaged Navier-Stokes(RANS)solver,including multi-dimensional upwind flux reconstruction(MUP),multi-dimensional limiter(MLP-u2)and multi-dimensional gradient reconstruction(MLR).The coupled multi-dimensional RANS solver is validated by several typical verification and validation(V&V)cases,including hypersonic flows over a cylinder,a blunt biconic,and a double-ellipsoid,with commonly used prismetrahedral hybrid grids.Finally,the coupled multi-dimensional solver is applied to simulating the heat flux distribution over a 3D engineering configuration,i.e.a Hermes-like space shuttle model.The obtained numerical results are compared with experimental data.The predicted results demonstrate that the coupled multi-dimensional approach has a good prediction capability on aerodynamic heating over a wide range of complex engineering configurations. 展开更多
关键词 Heat-flux prediction Unstructured grid Multi-dimensional gradient reconstruction Multi-dimensional limiter Multi-dimensional upwind scheme
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Modeling and Defending Passive Worms over Unstructured Peer-to-Peer Networks 认领 引用 被引量：8
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作者 王方伟 张运凯 马建峰 《Transactions of Tianjin University》 EI CAS 2008年第1期66-72,共7页
Passive worms can passively propagate through embedding themselves into some sharing files, which can result in significant damage to unstructured P2P networks. To study the passive worm behaviors, this paper firstly ... Passive worms can passively propagate through embedding themselves into some sharing files, which can result in significant damage to unstructured P2P networks. To study the passive worm behaviors, this paper firstly analyzes and obtains the average delay for all peers in the whole transmitting process due to the limitation of network throughput, and then proposes a mathematical model for the propagation of passive worms over the unstructured P2P networks. The model mainly takes the effect of the network throughput into account, and applies a new healthy files dissemination-based defense strategy according to the file popularity which follows the Zipf distribution. The simulation results show that the propagation of passive worms is mainly governed by the number of hops, initially infected files and uninfected files. The larger the number of hops, the more rapidly the passive worms propagate. If the number of the initially infected files is increased by the attackers, the propagation speed of passive worms increases obviously. A larger size of the uninfected file results in a better attack performance. However, the number of files generated by passive worms is not an important factor governing the propagation of passive worms. The effectiveness of healthy files dissemination strategy is verified. This model can provide a guideline in the control of unstructured P2P networks as well as passive worm defense. 展开更多
关键词 network security unstructured peer-to-peer networks passive worms propagationmodel patch dissemination strategy
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A Novel VOF-Type Volume-Tracking Method for Free-Surface Flows Based on Unstructured Triangular Mesh 认领 引用 被引量：8
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作者 及春宁 王元战 王建峰 《China Ocean Engineering》 SCIE EI 2005年第4期529-538,共10页
A novel VOF-type volume-tracking method for two-dimensional free-surface flows based on the unstructured triangular mesh is presented. Owing to the inherent merit of the unstructured triangular mesh in fitting curved ... A novel VOF-type volume-tracking method for two-dimensional free-surface flows based on the unstructured triangular mesh is presented. Owing to the inherent merit of the unstructured triangular mesh in fitting curved boundaries, this method can handle the free-surface problems with complex geometries accurately and directly, without introducing any complicated boundary treatment or artificial diffusion. The method solves the volume transport equation geometrically through the Modified Lagrangian-Eulerian Re-map （MLER） method, which is applied to advective fluid volumes. Moreover, the PLIC method is adopted to give a second-order reconstructed interface approximation. To validate this method, two advection tests were performed for the establishment of the accuracy and convergence rate of the solutions. Numerical results for these complex tests provide convincing evidence for the excellent solution quality and fidelity of the method. 展开更多
关键词 volume-of-fluid modified Lagrangian-Eulerian re-map （MLER） unstructured triangular mesh
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A three-dimensional semi-implicit unstructured grid finite volume ocean model 认领 引用 被引量：12
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作者 WANG Zhili GENG Yanfen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第1期68-78,共11页
A new three-dimensional semi-implicit finite-volume ocean model has been developed for simulating the coastal ocean circulation, which is based on the staggered C-unstructured non-orthogonal grid in the hor- izontal d... A new three-dimensional semi-implicit finite-volume ocean model has been developed for simulating the coastal ocean circulation, which is based on the staggered C-unstructured non-orthogonal grid in the hor- izontal direction and z-level grid in the vertical direction. The three-dimensional model is discretized by the semi-implicit finite-volume method, in that the free-surface and the vertical diffusion are semi-implicit, thereby removing stability limitations associated with the surface gravity wave and vertical diffusion terms. The remaining terms in the momentum equations are discretized explicitly by an integral method. The partial cell method is used for resolving topography, which enables the model to better represent irregular topography. The model has been tested against analytical cases for wind and tidal oscillation circulation, and is applied to simulating the tidal flow in the Bohal Sea. The results are in good agreement both with the analytical solutions and measurement results. 展开更多
关键词 three-dimensional model finite volume unstructured grid semi-implicit z-level grid
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Two-dimensional shallow water equations with porosity and their numerical scheme on unstructured grids 认领 引用 被引量：14
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作者 Zhi-li WANG Yan-fen GENG 《Water Science and Engineering》 EI CAS CSCD 2013年第1期91-105,共15页
In this study, porosity was introduced into two-dimensional shallow water equations to reflect the effects of obstructions, leading to the modification of the expressions for the flux and source terms. An extra porosi... In this study, porosity was introduced into two-dimensional shallow water equations to reflect the effects of obstructions, leading to the modification of the expressions for the flux and source terms. An extra porosity source term appears in the momentum equation. The numerical model of the shallow water equations with porosity is presented with the finite volume method on unstructured grids and the modified Roe-type approximate Riemann solver. The source terms of the bed slope and porosity are both decomposed in the characteristic direction so that the numerical scheme can exactly satisfy the conservative property. The present model was tested with a dam break with discontinuous porosity and a flash flood in the Toce River Valley. The results show that the model can simulate the influence of obstructions, and the numerical scheme can maintain the flux balance at the interface with high efficiency and resolution. 展开更多
关键词 shallow water equations with porosity source term,＂ Roe-type Riemann solver,＂ finitevolume method unstructured grid
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An efficient data structure for calculation of unstructured T-spline surfaces 认领 引用 被引量：3
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作者 Wei Wang Yang Zhang +1 位作者 Xiaoxiao Du Gang Zhao 《Visual Computing for Industry,Biomedicine,and Art》 EI 2019年第1期7-15,共9页
To overcome the topological constraints of non-uniform rational B-splines,T-splines have been proposed to define the freeform surfaces.The introduction of T-junctions and extraordinary points makes it possible to repr... To overcome the topological constraints of non-uniform rational B-splines,T-splines have been proposed to define the freeform surfaces.The introduction of T-junctions and extraordinary points makes it possible to represent arbitrarily shaped models by a single T-spline surface.Whereas,the complexity and flexibility of topology structure bring difficulty in programming,which have caused a great obstacle for the development and application of T-spline technologies.So far,research literatures concerning T-spline data structures compatible with extraordinary points are very scarce.In this paper,an efficient data structure for calculation of unstructured T-spline surfaces is developed,by which any complex T-spline surface models can be easily and efficiently computed.Several unstructured T-spline surface models are calculated and visualized in our prototype system to verify the validity of the proposed method. 展开更多
关键词 T-splines Non-uniform rational B-splines Unstructured T-mesh Extraordinary points
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A finite volume method for global electromagnetic induction forward modeling on collocated unstructured grids 认领 引用 被引量：3
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作者 Liang Yin ZhengYong Ren +1 位作者 HongBo Yao Cong Yang 《Earth and Planetary Physics》 CAS CSCD 2023年第1期57-65,共9页
Global electromagnetic induction provides an efficient way to probe the electrical conductivity in the Earth’s deep interior.Owing to the increasing geomagnetic data especially from high-accuracy geomagnetic satellit... Global electromagnetic induction provides an efficient way to probe the electrical conductivity in the Earth’s deep interior.Owing to the increasing geomagnetic data especially from high-accuracy geomagnetic satellites,inverting the Earth’s three-dimensional conductivity distribution on a global scale becomes attainable.A key requirement in the global conductivity inversion is to have a forward solver with high-accuracy and efficiency.In this study,a finite volume method for global electromagnetic induction forward modeling is developed based on unstructured grids.Arbitrary polyhedral grids are supported in our algorithms to obtain high geometric adaptability.We employ a cell-centered collocated variable arrangement which allows convenient discretization for complex geometries and straightforward implementation of multigrid technique.To validate the method,we test our code with two synthetic models and compare our finite volume results with an analytical solution and a finite element numerical solution.Good agreements are observed between our solution and other results,indicating acceptable accuracy of the proposed method. 展开更多
关键词 global electromagnetic induction mantle electrical conductivity finite volume method unstructured grids
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