Towards Three-Dimensional Global Stability Analysis of Transonic Shock Buffet

Analysis and Comparison of Transonic Buffet Phenomenon over Several Three-Dimensional Wings

“…A challenging 3D global stability analysis could state which hypothesis is closer to 3D transonic buffet. The only 3D global analysis performed until now by Timme and Thormann [10] does not really answer the question. Indeed, the analysis has been performed only at low value of α, and just the emergence of some destabilizing global modes approaching the imaginary axis is found.…”

“…Memmolo et al, after proposing a precise path for Lee's model consistent with the buffet frequency, performed a filtering of the acoustic field and showed that the buffet instability is either highly localized around the shock as observed by Crouch et al [7] or connected with the separation bubble dynamics. More recently, Timme and Thormann [10] performed a three-dimensional (3D) global stability analysis on a half wing/body configuration, by using the same approach as the one used by Crouch et al [6]. The emergence of a weakly damped global mode is found in the range α 2-3 deg, but no unstable mode has been found.…”

Transonic buffet instability: From two-dimensional airfoils to three-dimensional swept wings

“…Yet, Iorio et al [21], who performed a similar 3D analysis for the buffet phenomenon, did not find any 3D unstable modes. Similarly, Timme and Thormann [22] performed a 3D global stability analysis of the transonic buffet phenomenon on a realistic half-wing body configuration and only found a weakly damped global mode. It is only recently that Timme [23] found an unstable 3D mode on the same configuration but still did not answer the main question addressed in the present work: What is the link between 2D and 3D buffet?…”

Modal Analysis of a Laminar-Flow Airfoil under Buffet Conditions at Re = 500,000

“…There is great interest on global stability analysis of airfoils under buffet conditions (i.e. [6,21,22]), but very little work has been done to date using DNS data. In particular, we wish to explore the usefulness of the dynamic mode decomposition (DMD) procedure [23] to separate and analyse interactions between complex flow phenomena, such as buffet, shock waves, acoustic waves and flow instabilities that are known to exist for this case [16].…”