论文标题
代表对流不稳定性的移动参考框架中的局部本本元素
Localised eigenmodes in a moving frame of reference representing convective instability
论文作者
论文摘要
当代表具有流向大叶稳定方法的对流不稳定性机制时，结果对流向域截断的长度和边界条件具有敏感性。本文提出的方法通过考虑移动的参考框架来解决这种敏感性。在该框架中，这些频谱具有离散的特征值，其相应的特征功能在上游方向和下游方向上呈指数型衰减。因此，截断边界可以放置得足够远，以至于域长度和人工边界条件的两个变化都没有影响。频谱的离散性质使使用局部和非本地稳定性方法通过全局模式理论对大叶特征的独立近似进行独立近似。我们证明，在固定的参考框架中检索独立于设置的解决方案对于被考虑的流程可能是不可能的。
When representing convective instability mechanisms with the streamwise BiGlobal stability approach, results suffer from a sensitivity to the streamwise domain truncation length and boundary conditions. The methodology proposed in this paper resolves this sensitivity by considering a moving frame of reference. In that frame, the spectrum features discrete eigenvalues whose corresponding eigenfunctions decay exponentially in both the up- and downstream directions. Therefore, the truncation boundaries can be placed far enough that both variations in the domain length and artificial boundary conditions have no impact. The discrete nature of the spectrum enables the use of local and non-local stability methods to perform an independent approximation of the BiGlobal eigensolutions via global mode theory. We demonstrate that retrieving set-up-independent solutions in the stationary frame of reference is likely impossible for the considered flow.
