Vortex Structures in a Cavity Interacting with a Boundary Layer P.I.V. with Optical Flow postscript, pdf, Allecsandra Rambert, François Lusseyran, Pierre Gougat, Afif Elcafsi et Georges M. Quénot, XVème Congrès Français de Mécanique, papier 703, Nancy, France, 3-7 Septembre, 2001.

In order to characterize the evolution of three-dimensional coherent structures in a non-stationary flow, we developped a new experimental method by Particle Image Velovimetry (PIV) based on the Optical Flow algorithm. In the case of an interaction between a boundary layer and a cavity, three-dimensionnal phenomena are characterized by velocity fields measurements. This configuration is representative of atmospheric pollution. The high resolution of Optical Flow coupled with a PIV 3D velocity measurements will permit to better characterize the Reynolds tensor and vaildate the viscosity models used in the LES simulation.