R-B旋轉對流 – 探討旋轉主導體系的過渡

R-B旋轉對流 – 探討旋轉主導體系的過渡

Seminar:- Rotating Rayleigh-Bénard Convection: Probing the Transition to the Rotation Dominated Regime 

Most geo- and astrophysical flows are driven by strong thermal forcing and affected by high rotation. In these systems, direct measurements of the physical quantities are not possible due to their large scales, remoteness and complexity. A model containing the main physical constituents is rather beneficial. This approach is given by the problem of rotating Rayleigh-Bénard convection (RRBC): a rotating fluid layer heated from below and cooled from above. For large-scale systems, the governing parameters of RRBC take extreme values, leading to a regime of geostrophic turbulence.

In this talk, we present Lagrangian velocity and acceleration fluctuations and autocorrelations of tracers from experiments. We have found that the transition to rotation-dominated regime coincides with three phenomena; the vertical motions are suppressed, the vortical plumes penetrate further into the bulk and the vortical plumes interact less with their surroundings.

Finally, and if time allows, we will discuss some first results from a dedicated setup designed to study the unexplored parts of the geostrophic convection regime in detail. 
時間:2018.03.02(五) 15:00 ~ 16:00
地點:香港中文大學 科學館北座139室
講者:Prof. Herman CLERCX(Fluid Dynamics Laboratory, Department of Applied Physics Eindhoven University of Technology, the Netherlands)