Stochastic fluid structure interaction of three dimensional plates facing a uniform flow
Résumé
An experiment of a flat rectangular plate facing a uniform flow at Re= 264000 shows the importance on the base pressure loading of the asymmetric static modes of the turbulent wake. The plate is free to rotate around its small symmetry axis. For plates with aspect ratio κ < 6, the angular position exhibits strong random discontinuities between steady states of non zero angles. The steady states have long time durations, more than one order of magnitude larger than the convective timescale. The discontinuities, comparable to rare and violent events are due to strong fluid forces associated with the drastic global change of the three dimensional wake, mainly the switching between the static asym-metric modes. A clear transition occurs at κ = 6 for which the angular fluctuations are minimum leading for κ > 6 to a classical fluid structure interaction with periodic fluctuations. The transition is supported by a recent global stability analysis of rectangular fixed plates in the laminar regime.
Domaines
Sciences de l'ingénieur [physics]Origine | Fichiers produits par l'(les) auteur(s) |
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