The dynamics of decomposed multi-scale vortex filaments in two-dimensional bacterial flows

Hsiang Ying Chen^1*, Lin I¹

¹Department of Physics, National Central University, Taoyuan, Taiwan

* Presenter:Hsiang Ying Chen, email:yannafly1220@gmail.com

The multidimensional empirical mode decomposition is a technique allowed to extract different-scale intrinsic modes from 2D spatial signals. It is intriguing to revisit and understand the underlying mechanism and dynamics of vortices in two-dimensional turbulence by this method. In this work, we experimentally investigate the spatiotemporal dynamics of interacting multiscale vortex filaments in the self-propelled two-dimensional turbulent flows of E. coli suspensions in thin liquid films.
It is found that the decomposed vortex filaments from different scales but with the same helicity appear coherently and wind around with each other. The entanglement and intermode interactions of vorticity filaments are presented.

Keywords: 2D turbulence, multi-scale mode decomposition