European Journal of Computational Mechanics最新文献_第9页

Quasi-Isotropic Initial Triangulation of NURBS Surfaces NURBS曲面的拟各向同性初始三角剖分

IF 1.2

European Journal of Computational Mechanics Pub Date : 2020-11-23 DOI: 10.13052/EJCM2642-2085.2912

Daniel Herrero Adan, R. Cardoso

{"title":"Quasi-Isotropic Initial Triangulation of NURBS Surfaces","authors":"Daniel Herrero Adan, R. Cardoso","doi":"10.13052/EJCM2642-2085.2912","DOIUrl":"https://doi.org/10.13052/EJCM2642-2085.2912","url":null,"abstract":"Isotropic triangulation of NURBS surfaces provides high quality triangular meshes, where all triangles are equilateral. This isotropy increases representation quality and analysis accuracy. We introduce a new algorithm to generate quasi-isotropic triangulation on NURBS surfaces at once, with no prior meshing. The procedure consists of one front made of vertexes that advances in a divergence manner avoiding front collision. Vertexes are calculated by intersecting arcs whose radius is estimated by trapezoidal rule integration of directional derivatives. The parameter space is discretized in partitions such that the error of trapezoidal rule is controlled efficiently. A new space, called pattern space, is used to infer the direction of the arcs’ intersection. Derivatives, whose analytical computation is expensive, are estimated by NURBS surface fitting procedures, which increases the speed of the process. The resultant algorithm is robust and efficient. The mesh achieved possesses most of the triangles equilateral and with high uniformity of sizes. The performance is evaluated by measuring angles, vertex valences and size uniformity in different numerical examples.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":"1 1","pages":"27–82-27–82"},"PeriodicalIF":1.2,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43654178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Modeling and Simulation of Flow and Uranium Isotopes Separation in Gas Centrifuges Using Implicit Coupled Density-Based Solver in OpenFOAM 基于OpenFOAM中隐式耦合密度求解器的气体离心机流动和铀同位素分离建模与仿真

IF 1.2

European Journal of Computational Mechanics Pub Date : 2020-07-13 DOI: 10.13052/ejcm2642-2085.2911

V. Ghazanfari, A. Salehi, A. Keshtkar, M. Shadman, M. H. Askari

引用次数: 6

Computation of Second-order Design Sensitivities for Steady State Incompressible Laminar Flows Using the Extended Complex Variables Method 用扩展复变量法计算稳态不可压缩层流的二阶设计灵敏度

IF 1.2

European Journal of Computational Mechanics Pub Date : 2020-05-16 DOI: 10.13052/ejcm2642-2085.2863

M. Hassanzadeh

{"title":"Computation of Second-order Design Sensitivities for Steady State Incompressible Laminar Flows Using the Extended Complex Variables Method","authors":"M. Hassanzadeh","doi":"10.13052/ejcm2642-2085.2863","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.2863","url":null,"abstract":"In the current paper, the general procedure of the first and second-order sensitivity analysis is presented using the extended complex variables method (ECVM). In the traditional complex variables method, only the imaginary step is used for sensitivity analysis. However, in the ECVM, both of the real and imaginary parts are employed to improve the efficiency of the method. To show this, the ECVM is applied to the steady state incompressible laminar flow around a cylinder. The governing Navier-Stokes equations are solved by the finite element method and then the ECVM is employed. The results are validated through comparing with those of obtained by an analytical as well as the finite difference methods and the convergence rate is investigated. It is illustrated that the first-order sensitivity analysis is not influenced by the change of the step length for both of the traditional and extended complex variables methods. However, it is shown that unlike the traditional complex variables method, the ECVM is less dependent on the step size for calculating the second-order sensitivity. This can be considered as an enhancement in the efficiency of this method. Hence, the ECVM is suggested as an appropriate technique for calculating simultaneously the first and second-order sensitivities with high accuracy as well as low computational cost. The proposed method is applicable to a wide range of problems having simple or complex parameters.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":"1 1","pages":"605–634-605–634"},"PeriodicalIF":1.2,"publicationDate":"2020-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48970052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic Finite Element Analysis of Flexible Double Wishbone Suspension Systems with Different Damping Mechanisms 不同阻尼机构柔性双叉骨悬架系统动力学有限元分析

IF 1.2

European Journal of Computational Mechanics Pub Date : 2020-03-11 DOI: 10.13052/ejcm2642-2085.2862

Alaa A. Abdel Rahman, A. E. Nabawy, A. Abdelhaleem, S. Ali-Eldin

{"title":"Dynamic Finite Element Analysis of Flexible Double Wishbone Suspension Systems with Different Damping Mechanisms","authors":"Alaa A. Abdel Rahman, A. E. Nabawy, A. Abdelhaleem, S. Ali-Eldin","doi":"10.13052/ejcm2642-2085.2862","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.2862","url":null,"abstract":"Suspension systems in running vehicles keep the occupants comfortable and isolated from road noise, disturbances, and vibrations and consequently prevent the vehicle from damage and wearing. To attain comfortable and vibration isolation conditions, both material flexibility and damping should be considered in the considered suspension model. This paper presents an incremental finite element model to study and analyze the dynamic behavior of double wishbone suspension systems considering both material flexibility and damping effects. The flexibility of the suspension links are modeled with plane frame element based on Timoshenko beam hypothesis (TBH). On the other hand, the flexibility of joints connecting the suspension links together and with the vehicle chassis is modeled with the revolute joint element. To incorporate the damping effect, viscoelastic, viscous and proportional damping are considered. An incremental viscoelastic constitutive relations, suitable for finite element implementation, are developed. The developed finite element equations of motion are solved using the Newmark technique. The developed procedure is verified by comparing the obtained results with that obtained by the developed analytical solution and an excellent agreement is found. The applicability and effectiveness of the developed procedure are demonstrated by conducting parametric studies to show the effects of the road irregularities profiles, the vehicle speed, and the material damping on the transverse deflection and the resultant stresses of suspension system. Results obtained are supportive in the mechanical design, manufacturing processes of such type of structural systems.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2020-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43096028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Numerical Simulation Using a Modified Solver within OpenFOAM for Compressible Viscous Flows 可压缩粘性流OpenFOAM中改进求解器的数值模拟

IF 1.2

European Journal of Computational Mechanics Pub Date : 2020-03-02 DOI: 10.13052/ejcm2642-2085.2861

V. Ghazanfari, A. Salehi, A. Keshtkar, M. Shadman, M. H. Askari

{"title":"Numerical Simulation Using a Modified Solver within OpenFOAM for Compressible Viscous Flows","authors":"V. Ghazanfari, A. Salehi, A. Keshtkar, M. Shadman, M. H. Askari","doi":"10.13052/ejcm2642-2085.2861","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.2861","url":null,"abstract":"In this work, we attempted to develop an Implicit Coupled Density-Based (ICDB) solver using LU-SGS algorithm based on the AUSM+ up scheme in OpenFOAM. Then sonicFoam solver was modified to include viscous dissipation in order to improve its capability to capture shock wave and aerothermal variables. The details of the ICDB solver as well as key implementation details of the viscous dissipation to energy equation were introduced. Finally, two benchmark tests of hypersonic airflow over a flat plate and a 2-D cylinder were simulated to show the accuracy of ICDB solver. To verify and validate the ICDB solver, the obtained results were compared with other published experimental data. It was revealed that ICDB solver has good agreement with the experimental data. So it can be used as reference in other studies. It was also observed that ICDB solver enjoy advantages such as high resolution for contact discontinuity and low computational time. Moreover, to investigate the performance of modified sonicFoam, a case study of airflow over the prism was considered. Then the results of the modified sonicFoam were compared with the ICDB, rhoCentralFoam and sonicFoam solvers. The results showed that the modified sonicFoam solver possesses higher accuracy and lower computational time in comparison with the sonicFoam and rhoCentralFoam solvers, respectively.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":"1 1","pages":"541–572-541–572"},"PeriodicalIF":1.2,"publicationDate":"2020-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43651806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Numerical analysis of a SUSHI scheme for an elliptic-parabolic system modeling miscible fluid flows in porous media 模拟多孔介质中混相流体流动的椭圆-抛物系统SUSHI格式的数值分析

IF 1.2

European Journal of Computational Mechanics Pub Date : 2020-01-21 DOI: 10.13052/ejcm2642-2085.2855

Ouafa Soualhi, M. Mandari, M. Rhoudaf

引用次数: 0

Two Ways of Solving System of Nonlinear Structural Equations 求解非线性结构方程组的两种方法

IF 1.2

European Journal of Computational Mechanics Pub Date : 2020-01-14 DOI: 10.13052/ejcm2642-2085.2853

M. Rezaiee-Pajand, R. Naserian, H. Afsharimoghadam

引用次数: 1

A Second Order Weighted Numerical Scheme on Nonuniform Meshes for Convection Diffusion Parabolic Problems 对流扩散抛物问题非均匀网格的二阶加权数值格式

IF 1.2

European Journal of Computational Mechanics Pub Date : 2020-01-14 DOI: 10.13052/ejcm2642-2085.2854

L. Govindarao, J. Mohapatra

引用次数: 4

Stress Analysis by Two Cuboid Isoparametric Elements 两个长方体等参单元的应力分析

IF 1.2

European Journal of Computational Mechanics Pub Date : 2019-12-18 DOI: 10.13052/ejcm2642-2085.2851

M. Rezaiee-Pajand, A. Karimipour

引用次数: 6

Numerical Solution of MHD Incompressible Convection Flow in Channels 通道内MHD不可压缩对流流动的数值解

IF 1.2

European Journal of Computational Mechanics Pub Date : 2019-12-18 DOI: 10.13052/ejcm2642-2085.2852

Merve Gürbüz, M. Tezer-Sezgin

{"title":"Numerical Solution of MHD Incompressible Convection Flow in Channels","authors":"Merve Gürbüz, M. Tezer-Sezgin","doi":"10.13052/ejcm2642-2085.2852","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.2852","url":null,"abstract":"The purpose of this paper is to study numerically the influence of the magnetic field, buoyancy force and viscous dissipation on the convective flow and temperature of the fluid in a square cavity, lid-driven cavity, and lid-driven cavity with an obstacle at the center. The continuity, momentum and energy equations are coupled including buoyancy and magnetic forces, and energy equation contains Joule heating and viscous dissipation. The equations are solved in terms of stream function, vorticity and temperature by using polynomial radial basis function (RBF) approximation for the inhomogeneity and particular solution. The numerical solutions are obtained for several values of Grashof number (Gr), Hartmann number (M) for fixed Prandtl number Pr = 0:71 and fixed Reynolds number Re = 100 with or without viscous dissipation. It is observed that in the absence of obstacle, viscous dissipation changes the symmetry of the isotherms, and the dominance of buoyancy force increases with an increase in Gr, whereas decreases when the intensity of magnetic field increases. The obstacle in the lid-driven cavity causes a secondary flow on its left part. The effect of moving lid is weakened on the flow and isotherms especially for large Gr when the cavity contains obstacle.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":"1 1","pages":"411–432-411–432"},"PeriodicalIF":1.2,"publicationDate":"2019-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41478367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0