Control of unsteady wake flows using local oscillation of body surface: a data assimilation study
Résumé
Variational data assimilation (DA) can expand active flow control techniques to design wall actuators such as synthetic jets or plasma discharges which are difficult to model computationally due to ambiguous boundary conditions at the wall. Here, the control vector for the DA problem is formed by the initial flow and the solid boundary conditions for the body, that means its tangential speed at all times where no particular form is prescribed to the body motion. The control domain takes into account the modeled body surface by means of a direct forcing immersed boundary method (IBM). We consider a configuration of reference flow past a rotationally oscillating cylinder given by Mons & Sagaut, 2017, J. Fluid Mech.. The proposed methodology is applied to the reconstruction of a reference flow generated by a partial control restricted to an upstream part of the cylinder surface as given by Bergmann & Cordier, 2006, Phys. Fluids. DA is also employed to build wall conditions for a direct numerical simulation (DNS) of flow around an airfoil with local oscillation, from synthetic observations of the wake flow downstream the body.
Domaines
Sciences de l'environnementOrigine | Fichiers produits par l'(les) auteur(s) |
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