Speaker
Bernhard Mehlig
(University of Gothenburg)
Description
Recent studies show that spherical motile micro-organisms in
turbulence subject to gravitational torques gather in
down-welling regions of the turbulent flow. By analysing a
statistical model we analytically compute how shape affects
this preferential sampling and small-scale spatial
clustering (determining local encounter rates). By
recursively refining approximations for the paths the
organisms take through the flow we determine how
preferential sampling and small-scale clustering in the
model depend upon the dimensionless parameters of the
problem. We show that singularities ("caustics") affect the
dynamics of motile micro-organisms. Joint work with K.
Gustavsson, F. Berglund, and P.R. Jonsson.
