Analysis of the EMD behavior for separating coherent structure from interference fluctuations in homogeneous isotropic turbulence
Résumé
Empirical mode decomposition (EMD) is a method that relevant to decompose nonlinear and nonstationary time series into a sum of intrinsic modes functions (IMFs) and a low frequency trend. Here for the first time we used Bivariate EMD to separate large scale convection from turbulent velocity field. First a synthetic perturbation that mimics coherent structure is added to an experimental homogeneous isotropic turbulent field then the EMD was applied as a filter bank to separate this fluctuation from the initial field. The performance of the method has been evaluated by comparing turbulent properties of the recovered signal and ones without addition of fluctuations.