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Henri Sanness Salmon Colloquium

Fri. Nov. 26 12:30 PM - Fri. Nov. 26 01:20 PM
Contact: Andrea Wiebe
Location: via Zoom

Former Physics alumni, Henri Sanness Salmon.

Transport of floating particles on the free surface of turbulent streaming waters

We investigate experimentally the motion of floating particles of different shape and size on the turbulent free surface of a field scale meandering stream, using particle tracking velocimetry. Millimetre-sized spheres are used as tracers to obtain mean and fluctuating velocity fields of the surface flow. We focus on an approximately homogeneous region, where the single-point and two-point velocity statistics are consistent with the classic phenomenology of three-dimensional turbulence. We then consider centimetre-sized discs and rods, much larger than the dissipative scales but much smaller than the integral scales of the turbulence. As finite-sized inertial particles, these exhibit similar velocities as the small tracers but weaker and less intermittent accelerations. Consequently, the motion of the larger particles along their trajectories is more time-correlated, and their diffusion coefficient is larger. This is confirmed by the mean square displacement of single particles and mean square separation between particle pairs, both of which grow faster in time compared to the tracers. Discs are also found to disperse faster than similarly large rods, pointing at the important role of the objects’ shape in the transport dynamics.


Bio: BSc in Physics and Aerospace Engineering and Mechanics - Dual Degree Program University of Winnipeg and University of Minnesota (2019); MS in Aerospace Engineering and Mechanics - University of Minnesota (2021); Doctoral Student - Institute of Fluid Dynamics at ETH Zürich (current)


Missed the talk? Watch it here: https://uwcloud.uwinnipeg.ca/s/BZNtjPACDcgCNri