Characterizing multi-scale interaction in turbulence
Cristian C Lalescu1, Michael Wilczek1
1Max Planck Institute for Dynamics and Self-Organization
In fully developed turbulence, interactions take place between structures spanning a broad range of length and time scales. In this work, we aim to characterize these multi-scale interactions quantitatively. To this end, we identify the time scales relevant for structures of a given size, both from an Eulerian and a Lagrangian perspective. By employing filtering techniques in space and time, we compare turbulent velocity fields containing length scales above a given cutoff-scale with time-filtered fields. Varying the filter widths and times yields a precise picture of the various interactions. In a second step, we generalize the analysis to the Lagrangian frame to study the impact of large- and small-scale fluctuations on turbulent particle transport.
Keywords: Turbulence, Computational methods