Journal ArticleDOI
Origin of transonic buffet on aerofoils
TLDR
In this paper, the origins of transonic aerofoil buffet are linked to a global instability, which leads to shock oscillations and dramatic lift fluctuations, and the stability boundary, as a function of the Mach number and angle of attack, consists of an upper and a lower branch.Abstract:
Buffeting flow on transonic aerofoils serves as a model problem for the more complex three-dimensional flows responsible for aeroplane buffet. The origins of transonic aerofoil buffet are linked to a global instability, which leads to shock oscillations and dramatic lift fluctuations. The problem is analysed using the Reynolds-averaged Navier–Stokes equations, which for the foreseeable future are a necessary approximation to cover the high Reynolds numbers at which transonic buffet occurs. These equations have been shown to reproduce the key physics of transonic aerofoil flows. Results from global-stability analysis are shown to be in good agreement with experiments and numerical simulations. The stability boundary, as a function of the Mach number and angle of attack, consists of an upper and a lower branch – the lower branch shows features consistent with a supercritical bifurcation. The unstable modes provide insight into the basic character of buffeting flow at near-critical conditions and are consistent with fully nonlinear simulations. The results provide further evidence linking the transonic buffet onset to a global instability.read more
Citations
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Journal ArticleDOI
Modal Analysis of Fluid Flows: Applications and Outlook
Kunihiko Taira,Maziar S. Hemati,Steven L. Brunton,Yiyang Sun,Karthik Duraisamy,Shervin Bagheri,Scott T. M. Dawson,Chi-An Yeh +7 more
TL;DR: In this paper, the authors present applications of modal analysis techniques to study, model, and control canonical aerodynamic flows, including cylinder wakes, wall-bounded flows, airfoil wakes, and cavity flows.
Journal ArticleDOI
A review of recent developments in the understanding of transonic shock buffet
TL;DR: In this article, the authors present a review of recent investigations in the field of transonic shock buffet and highlight the importance of these experiments for the development of physical models stressed with a particular emphasis on the emergence of frequency synchronisation phenomenon.
Journal ArticleDOI
Mechanism of frequency lock-in in vortex-induced vibrations at low Reynolds numbers
TL;DR: In this paper, a CFD-based linear dynamics model combined with the direct Computational Fluid Dynamics/Computational Structural Dynamics (CFD/CSD) simulation method is utilized to study the physical mechanisms underlying frequency lock-in in vortex-induced vibrations (VIVs).
Journal ArticleDOI
Stability, Receptivity, and Sensitivity Analyses of Buffeting Transonic Flow over a Profile
TL;DR: In this paper, a transonic flow over the OAT15A supercritical profile is considered and the interaction between the shock wave and the turbulent boundary layer is investigated through numerical simulation and global stability analysis for a wide range of angles of attack.
Journal ArticleDOI
Prediction of Transonic Buffet by Delayed Detached-Eddy Simulation
TL;DR: In this article, a delayed detached-eddy simulation of the transonic buffet over a supercritical airfoil is performed, and the results are compared to an unsteady Reynolds-averaged Navier-Stokes simulation using the same baseline model as well as experimental data.
References
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Journal ArticleDOI
Self-sustained shock oscillations on airfoils at transonic speeds
TL;DR: In this article, a review of the physical mechanisms of the periodic shock motion on airfoils at transonic flow conditions are associated with the phenomenon of buffeting, and various modes of shock wave motion for different flow conditions and airfoil configurations are described.