二维平流输送问题的Euler-Taylor-Galerkin有限元方法及其数值实验
A Euler-Taylor-Galerkin Algorithm for 2-D Advection Problem and Numerical Tests
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摘要: 介绍了二维平流输送问题的Euler-Taylor-Galerkin(ETG)有限元方法,并进行了数值实验。笔者首先采用时间分裂技术将二维问题转化为一维问题,然后对每个一维问题应用ETG算法。为抑止在陡峭梯度区域附近出现的非物理振动和负值,使用了Forester的非线性滤波器。笔者采用余弦函数和高斯函数2种二维分布在一个纯旋转流场中输送的个例,研究了算法的性能并讨论了时间步长和空间网格分辨率对算法精度的影响。Abstract: A Euler-Taylor-Galerkin (ETG) algorithm for advection equation has been introduced. To solve the 2-dimensional problem, a time-splitting technique is employed and a Forester nonlinear filter is used to smooth out ripples and suppress negative value. The two dimensional advection test cases of a cosine hill and a Gaussian hill in a pure rotation velocity field are studied. The impacts of time step and spatial resolution on the accuracy of algorithm are also discussed.
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