O. Liot, A. Gay, D. Martin-Calle, J. Salort, M. Bourgoin, F. Chill`a

Lagrangian study of the inhomogeneity and unsteadiness in turbulent thermal convection

Although the Lagrangian approach is well developed since one decade to explore turbulent flows, few studies
have been proposed in turbulent convection. We propose an experimental Lagrangian study (by tracking hundreds
of sub-millimetric particles) in a large volume of a convection cell where a fraction of the Large Scale Circulation
(LSC) can be captured. The flow inhomogeneity has a large impact on the velocity distributions. By removing
the mean flow we are able to study turbulent convection unsteadiness such as sloshing of the LSC. Furthermore we
observe that the dispersion of particles pairs is also highly affected by the inhomogeneous mean flow and can be
easily modelled.