A New Characterization of Small-Scale Dynamics in Turbulent Flows

Explore a seminar on the new characterization of small-scale dynamics in turbulent flows presented by Rishita Das from the Indian Institute of Science, Bengaluru. Delve into the challenges of characterizing velocity gradient dynamics in turbulent flows due to their multi-fractal and intermittent nature. Discover a novel framework inspired by Kolmogorov's 1962 refined similarity hypothesis that separates the normalized velocity-gradient tensor geometry from its intermittent magnitude. Examine findings from direct numerical simulations of isotropic turbulence and turbulent channel flow, revealing universality in normalized velocity-gradient geometry across Reynolds numbers. Investigate the evolution of small-scale structures in turbulent flows within the state-space of normalized velocity-gradient invariants, considering various turbulence processes. Learn about a new data-driven model of Lagrangian velocity-gradient dynamics that demonstrates improved agreement with DNS results by separately modeling the bounded dynamics of the normalized velocity-gradient tensor and the intermittent magnitude dynamics.

A New Characterization of Small-scale Dynamics in Turbulent Flows by Rishita Das