Diffusion Properties Of Time-Resolved Trajectories In The Wake Behind A Cylinder

We investigate the computation of the Lagrangian second-order structure-function for describing the multiscale dynamics of turbulence based on measured particle trajectory data. Using time-resolved three-dimensional particle tracking velocimetry (4D-PTV), we statistically quantified turbulent properties of the anisotropic and inhomogeneous flow field behind a cylinder at a Reynolds number of 39 00. Lagrangian st atistical analysis has been performed on nearly 12000 trajectories for 4000 time steps.