Wavelet based eddy structure eduction from a backward facing step flow investigated using particle image velocimetry

The eddy structures shed in a backward facing step (BFS) flow are considered in this work. Particle image velocimetry (PIV) measurements are performed in the recirculating region located downstream of the step. These measurements are validated by comparison with data available in the literature. An automatic vortex detection algorithm is developed for the purpose of the automatic analysis of the experimental data to detect and characterize the eddy structures. This provides a database that can be further post-processed to obtain a statistical characterization of the vortices. The streamwise statistical evolution of the diameter and circulation of the cores of the detected vortices is evaluated and stored in a database. This database is used to propose an illustration of the energy contents of the detected eddy versus the core inverse size but also an ensemble average of a given class of vortices.