Lecturer: Mr. Omri Shaltiel (HUJI)
Abstract:
Rotating turbulence contains both large scale columnar structures, which evolve slowly and behave in many respects like two dimensional turbulence, and propagating inertial waves. These two components coexist over a wide range of scales and form a non-linear dynamical system. Its energy transfers and interactions remain the subject of ongoing debate, particularly regarding the role of each component and the mechanisms by which kinetic energy is transferred anisotropically through scales.
In this talk, I will present an experimental investigation of energy-transfer mechanisms in rotating turbulence. I will first discuss a transient experiment that reveals a non-local flattening of the energy spectrum. I will examine the dynamics of this transient process, showing the propagation of inertial waves and their role in transferring energy through scales. I will then show how decomposing the velocity field into a quasi-two-dimensional component and an inertial wave component reveals two coexisting cascades: an inverse cascade in the quasi-two-dimensional flow and a forward anisotropic cascade carried by inertial waves. Finally, I will present results on the interaction between large-scale vortical structures and inertial waves, and show how the vortical flow modifies wave propagation.