A non-linear observer for unsteady three-dimensional flows

Marcelo Buffoni (1) , Simone Camarri (2) , Angelo Iollo (1) , Edoardo Lombardi (1) , Maria-Vittoria Salvetti (2)

1 MC2 - Modélisation, contrôle et calcul
2 DIA - Dipartimento Ingegneria Aerospaziale "Lucio Lazzarino"

A method is proposed to estimate the velocity field of an unsteady flow using a limited number of flow measurements. The method is based on a non-linear low-dimensional model of the flow and on expanding the velocity field in terms of empirical basis functions. The main idea is to impose that the coefficients of the modal expansion of the velocity field give the best approximation to the available measurements and that at the same time they satisfy as close as possible the non-linear low-order model. The practical use may range from feedback flow control to monitoring of the flow in non-accessible regions. The proposed technique is applied to the flow around a confined square cylinder, both in two- and three-dimensional laminar flow regimes. Comparisons are provided. with existing linear and non-linear estimation techniques.

Mots clés: low-order models; dynamic estimation; non-linear observers

Domaines: Modélisation et simulation; Optimisation et contrôle [math.OC]; Physique Numérique [physics.comp-ph]; Dynamique des Fluides [physics.flu-dyn]

Marcelo Buffoni, Simone Camarri, Angelo Iollo, Edoardo Lombardi, Maria-Vittoria Salvetti. A non-linear observer for unsteady three-dimensional flows. [Research Report] RR-6117, INRIA. 2007. ⟨inria-00129332v2⟩