2020/01/13 by Koen J. Groot, Groot, Koen J., Sébastien Niessen +2
Engineering · Physics and Astronomy · #Computational Fluid Dynamics and Aerodynamics #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics and Turbulent Flows #Fluid Dynamics and Vibration Analysis #physics.flu-dyn
paper · pdf · doi:10.48550/arxiv.2001.04124
arxiv created 2020/01/13 · openalex publication_date 2020/01/13 · arxiv updated 2020/01/14 · openalex created_date 2020/01/23 · openalex updated_date 2026/07/28
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.