共查询到19条相似文献,搜索用时 93 毫秒
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研究了Brinkman-Forchheimer方程组解的结构稳定性.首先得到一些有用的先验界,然后在此基础上推出了解所满足的微分不等式,最后建立了解对Brinkman系数v的连续依赖性结果. 相似文献
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主要目的是将非协调类Carey元应用于非线性Sobolev-Galpern型湿气迁移方程.借助于单元的特殊性质(即在能量模意义下相容误差比插值误差高一阶)、线性三角元的高精度分析以及平均值技巧,得到了解的超逼近性质.进一步地利用插值后处理技术导出了整体超收敛结果. 相似文献
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利用H-增生映射的性质,得到一类非线性Neumann边值问题解的存在唯一性的结论.文中所研究的方程是对以往工作的推广.证明方法得到简化.文中列举的一些例子还有助于进一步了解H-增生映射. 相似文献
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利用单调迭代的方法得到了一类具p-Laplacian算子的多点边值问题单调迭代正解的存在性,同时也得到了解的相应迭代序列. 相似文献
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研究了一类在无穷区间上具有p-Laplacian算子的边值问题的迭代正解.利用单调迭代方法得到问题的迭代正解存在性的充分条件,同时得到了解的相应迭代序列,最后给出例子证明所得结论. 相似文献
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线性矩阵方程的埃尔米特广义反汉密尔顿半正定解 总被引:1,自引:0,他引:1
利用埃尔米特广义反汉密尔顿半正定矩阵的表示定理,作者建立了线性矩阵方程在埃尔米特广义反汉密尔顿半正定矩阵集合中可解的充分必要条件,得到了解的一般表达式.对于逆特征值问题,也得到了可解的充分必要条件.对于任意一个 n 阶复矩阵,得到了相关最佳逼近问题解的表达式. 相似文献
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In this paper,a new higher order Wilson element is presented,and the convergence is proved.Then the interpolation postprocessing technique is used to obtain the global superconvergence and posterior error estimate of higher accuracy of this new element for the Sobolev type equations. 相似文献
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PRECONDITIONING HIGHER ORDER FINITE ELEMENT SYSTEMS BY ALGEBRAIC MULTIGRID METHOD OF LINEAR ELEMENTS
Yun-qing Huang Shi Shu Xi-jun Yu 《计算数学(英文版)》2006,24(5):657-664
We present and analyze a robust preconditioned conjugate gradient method for the higher order Lagrangian finite element systems of a class of elliptic problems. An auxiliary linear element stiffness matrix is chosen to be the preconditioner for higher order finite elements. Then an algebraic multigrid method of linear finite element is applied for solving the preconditioner. The optimal condition number which is independent of the mesh size is obtained. Numerical experiments confirm the efficiency of the algorithm. 相似文献
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本文讨论分析非协调区域分解Lagrange乘子法对二阶椭圆型方程Dirichlet问题的有限元超收敛现象。文中通过利用积分恒等式,适宜地引进L2投影过渡以及高次插值后处理等技巧,经过一系列误差分析及估计,得到了高出半阶的超收敛结果,实现了非协调区域分解法与高精度算法的结合。 相似文献
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本文借助双线性元积分恒等式技巧,对粘弹性方程的类Wilson元解进行了高精度分析.通过证明类 Wilson元的非协调误差在矩形网格下可以达到O(h3)这一独特性质及利用插值后处理技术给出了H1模意义下O(h2)阶的超逼近和整体超收敛结果.进而通过构造合适的外推格式,得到具有更高阶O(h3)精度的数值逼近解. 相似文献
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The application of the mortar method in contact mechanics is motivated by the limited use of well known elements, for example the node‐to‐segment (NTS) element, see [1]. The NTS element contains a strong projection of the displacements from one contacting body to the next. Coupling of this element type with higher order shape functions leads to a loss of accuracy of contact stresses. In contrast to this, the mortar element has the advantage of a weak projection. Therefore, consistent coupling with continuum elements of higher order is possible. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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ACCURACY ANALYSIS FOR QUASI-WILSON ELEMENT 总被引:9,自引:0,他引:9
1IntroductionItiswellknownthattheconvergencebehaviorofthehausnonconformingWilsonel-ementismuchbetterthanofconforndllgbilinearelement,soWilsonelementiswidelyu8edinengineeringcomputation.ButWilsonelementisonlyconvergentforrectangularandpar-allelograxnmeshes.Inordertoextendthiselementtoarbitraryquadrilateralmeshes,variousimProvedWilsonelementsweredeveloped,suchasQP6element,generalizedisoparanletricelement,isoparametricQuasiconformingelement,andsoon(see[1-3]).However,the8hapefunctionsofallthes… 相似文献
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Jan H. Brandts 《Applications of Mathematics》2009,54(3):225-235
We show that a non-standard mixed finite element method proposed by Barrios and Gatica in 2007, is a higher order perturbation
of the least-squares mixed finite element method. Therefore, it is also superconvergent whenever the least-squares mixed finite
element method is superconvergent. Superconvergence of the latter was earlier investigated by Brandts, Chen and Yang between
2004 and 2006. Since the new method leads to a non-symmetric system matrix, its application seems however more expensive than
applying the least-squares mixed finite element method.
Dedicated to Ivan Hlaváček on the occasion of his 75th birthday 相似文献
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Shangyou Zhang Zhimin Zhang Qingsong Zou 《Numerical Methods for Partial Differential Equations》2017,33(6):1859-1883
We propose a local postprocessing method to get a new finite element solution whose flux is conservative element‐wise. First, we use the so‐called polynomial preserving recovery (postprocessing) technique to obtain a higher order flux which is continuous across the element boundary. Then, we use special bubble functions, which have a nonzero flux only on one face‐edge or face‐triangle of each element, to correct the finite element solution element by element, guided by the above super‐convergent flux and the element mass. The new finite element solution preserves mass element‐wise and retains the quasioptimality in approximation. The method produces a conservative flux, of high‐order accuracy, satisfying the constitutive law. Numerical tests in 2D and 3D are presented.© 2017 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 33: 1859–1883, 2017 相似文献