Point and Line Implicit Methods to Improve the Efficiency and Robustness of the DLR TAU Code
Point and Line Implicit Methods to Improve the Efficiency and Robustness of the DLR TAU Code
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提高 DLR TAU 代码效率和鲁棒性的点线隐式方法
DOI：
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发表时间：
2013
期刊：
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通讯作者：
S. Langer
中科院分区：
文献类型：
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作者：
S. Langer
本文提出了一种线隐式预处理的多级Runge-Kutta方法，以显着提高逼近高雷诺数粘性流稳态解的收敛速度。龙格-库塔法被用来作为一个光滑的凝聚多重网格法的背景下，非结构化网格。一个简化的一阶近似的雅可比矩阵的剩余函数被用作预条件。利用确定高单元拉伸的网格区域的预定线来提取雅可比矩阵的相关部分。使用基于加权图的有效算法来识别线。这具有的优点是，在网格中的任何地方都确定了高纵横比单元，例如也在机翼的尾流中。
We present a line implicit preconditioned multistage Runge-Kutta method to significantly improve the convergence rate for approximating steady state solutions of high Reynolds number viscous flows. The Runge-Kutta method is used as a smoother in the context of an agglomerated multigrid method for unstructured grids. A simplification of a first order approximation to the Jacobian of the residual function is used as a preconditioner. Predetermined lines identifying mesh regions of high cell stretching are exploited to extract the relevant parts of the Jacobian matrix. The lines are identified using an efficient algorithm based on a weighted graph. This has the advantage that high aspect ratio cells are determined everywhere in the mesh, for example also in the wake of a wing.