Stochastic modelling of unsteady vortex dynamics and its statistical verification in experiments

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Tobias Bölle

Le vendredi 7 avril à 11h00, salle de séminaires IRPHE

Abstract : Vortices are important building blocks of fluid flows on various scales, governing dynamics in various applications from geophysics to engineering. The prototype of unsteady vortex dynamics is called meandering. Despite a common observation and a multitude of studies since the 1970s, its mechanism and origin remain puzzling. Recently, we developed a model for vortex meandering using concepts from non-equilibrium statistical physics, in particular an analogy to Brownian motion. Since a preliminary comparison with experiments was very encouraging, we conducted a systematic statistical analysis of an experimental database gathered at ONERA. Confirmation of the model would have important implications for vortex dynamics, including the closure problem, linearity of the dynamics, stability, the typical frequency signature and reduced-order modelling. In this talk, we give an overview of these recent findings in modelling, verification and consequences.

Tobias BÖLLE, Institute for Atmospheric Physics, Allemagne