Dresden 2020 – scientific programme
The DPG Spring Meeting in Dresden had to be cancelled! Read more ...
Parts | Days | Selection | Search | Updates | Downloads | Help
DY: Fachverband Dynamik und Statistische Physik
DY 3: Fluid Physics of Turbulence
DY 3.2: Talk
Monday, March 16, 2020, 10:00–10:15, ZEU 118
Statistical geometry of material loops in turbulence — •Lukas Bentkamp1,2, Cristian Constantin Lalescu1, Theodore Dimitrios Drivas3, and Michael Wilczek1,2 — 1Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077, Göttingen, Germany — 2Faculty of Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany — 3Department of Mathematics, Princeton University, Princeton, NJ 08544, United States of America
Understanding turbulent transport involves a close investigation of the multi-scale properties of turbulence, since they impose different transport mechanisms at each scale. At small scales, for example, chaos drives trajectories of initially close particles to diverge exponentially. By considering extended structures like material lines, which are passively advected and deformed by the flow, we probe not only this exponential separation, but the general stretch-and-fold mechanisms that lead to turbulent mixing at all scales. Here, we present a study of the statistical geometry of closed material lines. In particular, we complement fully resolved direct numerical simulations of homogeneous turbulence with the analytically tractable Kraichnan model, which allows, for example, for a closer investigation of the fractal dimension, length, curvature and torsion of the loops. By studying these quantities, we gain insight into the geometrical structure of the underlying turbulent flow.