Boundary Elements and other Mesh Reduction Methods XLII最新文献_第2页

ADAPTIVE RBF-FD METHOD FOR POISSON’S EQUATION 泊松方程的自适应rbf-fd方法

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420131

J. Slak, G. Kosec

引用次数: 3

ANALYTICAL 3D BOUNDARY ELEMENT IMPLEMENTATION OF FLAT TRIANGLE AND QUADRILATERAL ELEMENTS FOR POTENTIAL AND LINEAR ELASTICITY PROBLEMS 解析三维边界元实现的平面三角形和四边形单元的潜在和线性弹性问题

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420011

N. Dumont, Tatiana Galvão Kurz

{"title":"ANALYTICAL 3D BOUNDARY ELEMENT IMPLEMENTATION OF FLAT TRIANGLE AND QUADRILATERAL ELEMENTS FOR POTENTIAL AND LINEAR ELASTICITY PROBLEMS","authors":"N. Dumont, Tatiana Galvão Kurz","doi":"10.2495/BE420011","DOIUrl":"https://doi.org/10.2495/BE420011","url":null,"abstract":"This paper introduces a formulation for 3D potential and linear elasticity problems that end up with the analytical handling of all regular, improper, quasi-singular, singular and hypersingular integrals of an implementation using linear triangle (T3) elements. The extension to flat Q4 and T6 elements is almost straightforward. Results at arbitrarily located internal points are also given analytically. The formulation is based on a generalized transformation to subtriangle coordinates that simplifies the problem’s description and enables the adequate interpretation of all relevant geometric features of a discretized boundary segment, so that it becomes possible to arrive at manageable analytical expressions of all integrals. The paper outlines the main concepts and computational features of the proposed formulation, based on an array with all pre-evaluated integrals required in an implementation. An example of 3D potential problems illustrates all particular cases and the most challenging topological configurations one might deal with in practical applications. The procedure may be easily implemented in a general boundary element code, as the usual numerical quadrature schemes for source points sufficiently far from the integration field remain applicable. There is a work in progress for the implementation of the procedure in the frame of a fast multipole algorithm.","PeriodicalId":429597,"journal":{"name":"Boundary Elements and other Mesh Reduction Methods XLII","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131222367","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: 6

COUPLED FINITE AND BOUNDARY ELEMENT METHOD FOR SOLVING MAGNETIC HYSTERESIS PROBLEMS 求解磁滞问题的有限与边界元耦合方法

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420111

I. Stupakov, M. Royak, N. Kondratyeva

引用次数: 1

EXACT TIME DEPENDENT CALCULATIONS FOR FLUIDS AND SOLIDS 流体和固体的精确时间依赖计算

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420151

E. Kansa

引用次数: 0

GLOBAL SINGULAR BOUNDARY METHOD FOR SOLVING 2D NAVIER–STOKES EQUATIONS 求解二维navier-stokes方程的全局奇异边界法

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420181

J. Mužík, R. Bulko

引用次数: 0

IMMERSED BOUNDARY METHOD APPLICATION AS A WAY TO BUILD A SIMPLIFIED FLUID-STRUCTURE MODEL 浸入边界法作为一种建立简化流固模型的方法

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420221

J. Borges, M. Lourenço, E. Padilla, C. Micallef

引用次数: 2

MESH-FREE ANALYSIS OF PLATE BENDING PROBLEMS BY MOVING FINITE ELEMENT APPROXIMATION 平板弯曲问题的无网格移动有限元逼近分析

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420191

V. Sládek, J. Sládek, M. Repka

引用次数: 3

3D CAUCHY PROBLEM FOR AN ELASTIC LAYER: INTERFACIAL CRACKS DETECTION 弹性层三维柯西问题:界面裂纹检测

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420251

A. Galybin, S. Aizikovich

引用次数: 0

NEW BOUNDARY ELEMENT FORMULATION FOR THE SOLUTION OF LAPLACE’S EQUATION 拉普拉斯方程解的新边界元公式

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420061

J. Lobry

{"title":"NEW BOUNDARY ELEMENT FORMULATION FOR THE SOLUTION OF LAPLACE’S EQUATION","authors":"J. Lobry","doi":"10.2495/BE420061","DOIUrl":"https://doi.org/10.2495/BE420061","url":null,"abstract":"The boundary element method (BEM) is typically used for solving potential problems and has several advantages over the traditional finite element method (FEM). However, the normal derivative of the potential appears explicitly as an unknown, with some inherent ambiguity at the corner nodes. Moreover, the BEM requires time consuming numerical integration (Gaussian quadrature) along the boundary of the domain. In this paper, we propose a new approach of BEM by introducing the weak nodal “cap” flux approach defined in the context of the finite element method. The domain integrals are eliminated at the discrete level by introducing the FEM approximation of the fundamental solutions at every node of the related mesh as basic functions in the Galerkin formulation of the BVP under study. The implementation of this new technique appears to be simpler as no numerical integration on the boundary of the domain is required so that the method leads to a substantially reduced computational burden. Our method is compared to the classical BEM for the numerical solution of the two-dimensional Laplace equation. It is observed that the normal flux presents a better behaviour at corners. A loss of accuracy may occur but it is compensated by a smaller execution time, allowing a finer mesh.","PeriodicalId":429597,"journal":{"name":"Boundary Elements and other Mesh Reduction Methods XLII","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134457644","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

NUMERICAL SCHEMES FOR VORTEX SHEET INTENSITY COMPUTATION IN VORTEX METHODS TAKING INTO ACCOUNT THE CURVILINEARITY OF THE AIRFOIL SURFACE LINE 考虑翼型表面曲线的旋涡法中旋涡片强度计算的数值格式

Boundary Elements and other Mesh Reduction Methods XLII Pub Date : 2019-09-10 DOI: 10.2495/BE420241

K. Kuzmina, I. Marchevsky

{"title":"NUMERICAL SCHEMES FOR VORTEX SHEET INTENSITY COMPUTATION IN VORTEX METHODS TAKING INTO ACCOUNT THE CURVILINEARITY OF THE AIRFOIL SURFACE LINE","authors":"K. Kuzmina, I. Marchevsky","doi":"10.2495/BE420241","DOIUrl":"https://doi.org/10.2495/BE420241","url":null,"abstract":"In vortex methods, vorticity is the primary computed variable. The problem of the accuracy improvement of vorticity generation simulation at the airfoil surface line in 2D vortex methods is considered. The generated vorticity is simulated by a thin vortex sheet at the airfoil surface line, and it is necessary to determine the intensity of this sheet at each time step. It can be found from the no-slip boundary condition, which leads to a vector boundary integral equation. There are two approaches to satisfy this equation: the first one leads to a singular integral equation of the 1st kind, while the second one leads to a Fredholm-type integral equation of the 2nd kind with bounded kernel for smooth airfoils. Usually, for numerical solution of the boundary integral equation, the airfoil surface line is replaced by a polygon, which consists of straight segments (panels). A discrete analogue of the integral equation can be obtained using the Galerkin method. Different families of basis and projection functions lead to numerical schemes with different complexity and accuracy. For example, a numerical scheme with piecewise-constant basis functions provides the first order of accuracy for vortex sheet intensity, and a numerical scheme with piecewise-linear functions gives the second order of accuracy. However, the velocity field near the airfoil surface line is also of interest. In the case of rectilinear airfoil surface line discretization, the accuracy of velocity field reconstruction has no more than the first order of accuracy for both, piecewise-constant and piecewise-linear numerical schemes. In order to obtain a higher order of accuracy for velocity field reconstruction, it is necessary to take into account the curvilinearity of the airfoil surface line. In this research, we have developed such an approach, which provides the second order of accuracy both, for vortex sheet intensity computation and velocity field reconstruction.","PeriodicalId":429597,"journal":{"name":"Boundary Elements and other Mesh Reduction Methods XLII","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132146910","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