共查询到19条相似文献，搜索用时 46 毫秒
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通过基于变系数可分离变量情形下限定扰动边界条件求解子问题,使多尺度基函数能很好地捕获模型问题的微观信息;该数值模拟方法仅在粗网格水平即可得到精确、收敛的结果。研究表明,运用多尺度有限元法进行复杂的多尺度数值模拟,既可节约计算资源又能保证计算的精度。 相似文献
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用数值法中最常用的有限差分法计算柱体三维静电场的泊松方程,计算有限网格点上的函数值近似逼近连续区域内的真实解,在计算机的辅助下,计算出电磁场的数值解. 相似文献
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线性多步方法是解常微分方程的一种数值解法,在计算中需要知道若干个初始值进行迭代。而初值一般情况下是通过其他迭代法估计出的,所以初值的不精确会导致该方法计算出的结果精度发生变化,因此对这种情况的计算结果精度进行了讨论。 相似文献
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本文主要利用薄板样条径向基插值的无网格特解方法求解一维双曲电报方程的数值解,并通过数值试验与精确解的比较证明了这种方法的精度是很好的。 相似文献
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作为自适应方法的一种,移动网格技术(Adaptive Moving Mesh)已经被广泛应用于计算流体力学的数值模拟.将非结构三角形网格单元上的RKDG方法与自适应移动网格方法相结合,在RKDG每一个时间步后进行网格移动,得到更新后的网格点和插值函数系数等,然后再次利用DG方法求解更新过的网格点上的数值解,由此进入下一次循环.数值算例对加自适应移动网格方法前后进行了比较,计算结果表明该方法稳健并且高效. 相似文献
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丁晓陈璐江山 《南通职业大学学报》2023,(3):58-62
为提高二维矢量型Stokes方程的求解精度和收敛阶,应用有限元法进行数值模拟。基于变分虚功原理,构造Lagrange型二次元基函数以形成有限元空间,针对流速的矢量分量形成相应的代数方程组并求解。图像模拟和数值结果均验证,高次有限元解真实有效地逼近了Stokes方程的精确解,且在不同范数度量下,高次有限元格式数值求解方法的精度和收敛阶均达预期。 相似文献
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无损检测信号快速三维有限元模拟的组合方法 总被引：1，自引：0，他引：1
提出了一种基于三维有限元的电磁无损检测缺损响应快速模拟的组合方法, 该方法由三项技术构成, 分别是局部计算技术、差场技术和迭代解技术. 采用局部计算技术, 可以将三维计算区域限制在缺损附近的一个较小范围; 使用差场技术, 无缺损情形下的轴对称解可以用来简化三维网格生成以及快速获得三维解答; 而应用迭代解技术, 可以加速无损探头信号有限元模拟的矩阵方程求解. 实例计算表明本文方法是正确有效的, 可以节省大量的计算机资源. 相似文献
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采用有限元分析软件ANSYS对网格框架墙体进行了数值模拟,并结合前期试验,进行了数值结果与试验结果的比较。比较分析认为ANSYS软件能够较好地模拟墙体内力和变形发展的全过程以及裂缝的形成与发展过程,可以满足实际工程实施与科学研究的精度要求。在此研究基础上,又对前期试验中没有涉及到的其他参数进行了模拟,从而完善了影响钢筋混凝土网格框架新型墙体抗震的其他因素。 相似文献
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研究目的:为液体润滑端面密封空化问题的数值模拟提供一种高效精确的计算方法。创新要点:1.采用流线迎风SUPG有限元法求解具有对流扩散特征的控制方程;2.针对未知量的互补关系提出了一种高效的数值迭代技术;3.提供了针对润滑液膜空化问题的网格自适应技术。重要结论:1.相比文献算法,本文算法具有计算速度快,计算精度高的优点;2.空化区域和大压力梯度区域的计算网格得到加密。 相似文献
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Mesh size effect in numerical simulation of blast wave propagation and interaction with structures 总被引：3，自引：0，他引：3
Numerical method is popular in analysing the blast wave propagation and interaction with structures.However,because of the extremely short duration of blast wave and energy trans-mission between different grids,the numerical results are sensitive to the finite element mesh size.Previous numerical simulations show that a mesh size acceptable to one blast scenario might not be proper for another case,even though the difference between the two scenarios is very small,indicating a simple numerical mesh size convergence test might not be enough to guarantee accu-rate numerical results.Therefore,both coarse mesh and fine mesh were used in different blast scenarios to investigate the mesh size effect on numerical results of blast wave propagation and interaction with structures.Based on the numerical results and their comparison with field test re-sults and the design charts in TM5-1300,a numerical modification method was proposed to correct the influence of the mesh size on the simulated results.It can be easily used to improve the accu-racy of the numerical results of blast wave propagation and blast loads on structures. 相似文献
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构造了Simpson、高斯及一个含导数项三类数值积分公式的对偶格式,得到它们对应的校正解,提高了对应数值积分公式的数值计算精度。最后,给出了几个数值算例,比较了用三类数值积分公式及其对偶解与校正解进行计算的数值结果．计算结果表明校正解和对偶解具有比三类数值积分近似解更好的精度和更快的收敛速度。 相似文献
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本描述了对有需要看重分析的局部区域的电磁场进行有限元分析的复合网格法．这种方法基于通常的有限元方法，有总体分析，局部分析和修正后的总体分析3个基本步骤．在前2步中，利用较粗的网格进行总体分析，得到节点的电势，将其作为后续进一步分析的局部区域的人工边界条件．将这些有了边界条件的局部区域用更精细的网格进行分析，得到更为精确的电势与密度分布．在第3步中，进行修正后的总体分析，通过迭代不断改进结果，直到满足给定的求解精度，得到更好的电势与密度分布的结果．数值实验表明，与通常的有限元方法相比，复合网格法在得到同样求解精度的结果时所耗的计算时间要少得多． 相似文献
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A meshless local discontinuous Petrov-Galerkin (MLDPG) method based on the local symmetric weak form (LSWF) is presented with the application to blasting problems. The derivation is similar to that of mesh-based Runge-Kutta Discontinuous Galerkin (RKDG) method. The solutions are reproduced in a set of overlapped spherical sub-domains, and the test functions are employed from a partition of unity of the local basis functions. There is no need of any traditional non-overlapping mesh either for local approximation purpose or for Galerkin integration purpose in the presented method. The resulting MLDPG method is a meshless, stable, high-order accurate and highly parallelizable scheme which inherits both the advantages of RKDG and meshless method (MM), and it can handle the problems with extremely complicated physics and geometries easily. Three numerical examples of the one-dimensional Sod shock-tube problem, the blast-wave problem and the Woodward-Colella interacting shock wave problem are given. All the numerical results are in good agreement with the closed solutions. The higher-order MLDPG schemes can reproduce more accurate solution than the lower-order schemes. 相似文献
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In this paper, both measurements and numerical simulations of railway induced vibration are discussed. A measurement campaign has been carried out along the high-speed railway track in Lincent, Belgium. The experimental determination of transfer functions and vibration velocity during train passages are discussed. A numerical model is introduced to predict the transfer functions and the vibration velocity during train passages. The comparison of experimental and numerical results demonstrates the importance of accurate numerical models and input data. The results are obtained in the framework of the development of a hybrid prediction method, where numerical and experimental data can be combined to improve the prediction accuracy for railway induced vibration. 相似文献
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田振夫 《上海大学学报(英文版)》2006,10(6):558-560
Numerical si mulation of complex flow fields withmulti-scale structures is one of the most i mportant andchallenging branches of computational fluid dynamics .Fromlinear analysis and numerical experi ments it hasbeen discovered that the higher-order accurate methodcan give reliable and efficient computational results ,aswell as better resolution of the complex flow fieldswith multi-scale structures . Compact finite differenceschemes , which feature higher-order accuracy andspectral-like resolu… 相似文献
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The technique of adaptive tree mesh is an effective way to reduce computational cost through automatic adjustment of cell size according to necessity. In the present study, the 2D numerical N-S solver based on the adaptive quadtree mesh system was extended to a 3D one, in which a spatially adaptive octree mesh system and multiple particle level set method were adopted for the convenience to deal with the air-water-structure multiple-medium coexisting domain. The stretching process of a dumbbell was simulated and the results indicate that the meshes are well adaptable to the free surface. The collapsing process of water column impinging a circle cylinder was simulated and from the results, it can be seen that the processes of fluid splitting and merging are properly simulated. The interaction of second-order Stokes waves with a square cylinder was simulated and the obtained drag force is consistent with the result by the Morison’s wave force formula with the coefficient values of the stable drag component and the inertial force component being set as 2.54. 相似文献
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吴开腾 《内江师范学院学报》2008,23(12)
分析了基本无振荡(ENO)格式的特点,重构多项式是ENO格式构造的核心部分;由通量值作为插值点,构造了一个简单的高精度格式;引入三阶TVD Runge-Kutta时间离散;编写了基于ENO格式的三维计算程序;就三维欧拉方程的激波反射与双赫反射问题进行了数值计算,给出了空中爆炸场的三维压力分布图.数值试验结果表明,格式所具有的高精度和基本无振荡性质,能够满足实际计算的需要. 相似文献