A Normal Mode Stability Analysis of Numerical Interface Conditions for Fluid/Structure Interaction
A Normal Mode Stability Analysis of Numerical Interface Conditions for Fluid/Structure Interaction
复制标题
流体/结构相互作用数值界面条件的简正模稳定性分析
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
B. Sjögreen
中科院分区：
文献类型：
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作者：
J. Banks;B. Sjögreen
在可压缩流体与线性弹性固体耦合的多物理场计算中，在流体和固体之间的界面处强制法向速度和法向应力的连续性是标准的。在数值格式中，有许多方法可以在离散近似中加强速度和应力连续性。本文对线性化问题进行了正模稳定性分析，研究了迎风型有限差分格式近似模型问题的不同数值界面条件的稳定性。分析表明，根据固体和流体之间的密度比，一些数值界面条件是稳定的最大CFL限制，而其他数值界面条件遭受严重减少的稳定CFL限制。本文还提出了一种新的界面条件，作为一个简化的特征边界条件，这是证明不遭受任何减少的稳定CFL限制。一维数值实验表明，新的界面条件对于可压缩流体与线弹性固体耦合的非线性Euler方程的计算也是稳定的。AMS科目分类：65M12、35L60、35L65
In multi physics computations where a compressible fluid is coupled with a linearly elastic solid, it is standard to enforce continuity of the normal velocities and of the normal stresses at the interface between the fluid and the solid. In a numerical scheme, there are many ways that velocityand stress-continuity can be enforced in the discrete approximation. This paper performs a normal mode stability analysis of the linearized problem to investigate the stability of different numerical interface conditions for a model problem approximated by upwind type finite difference schemes. The analysis shows that depending on the ratio of densities between the solid and the fluid, some numerical interface conditions are stable up to the maximal CFL-limit, while other numerical interface conditions suffer from a severe reduction of the stable CFL-limit. The paper also presents a new interface condition, obtained as a simplified characteristic boundary condition, that is proved to not suffer from any reduction of the stable CFL-limit. Numerical experiments in one space dimension show that the new interface condition is stable also for computations with the non-linear Euler equations of compressible fluid flow coupled with a linearly elastic solid. AMS subject classifications: 65M12, 35L60, 35L65