Multiple Instabilities and transition to turbulence

Instabilities are a key feature of the transition to turbulence in many configurations. They are observed in simple fluid flows under thermal or mechanical driving as well as in complex fluids such as granular media, fluids with interfaces, reactive fluids, non-newtonian fluids, ferrofluids... Instabilities induce the formation of patterns with rich spatiotemporal dynamics. They may also arise successively leading to disorder (chaos or turbulence). Recently, even instabilities of fully turbulent flows have been reported. In any case, the mechanisms responsible for the instabilities remain often difficult to detect among the various parameters that come into play. The aim of this colloquium is to gather around Innocent Mutabazi researchers who collaborate or have collaborated with him or share with him a long interest in the study of instabilities and the transition to turbulence.

It will be organized around the following themes:
- Instabilities and formation of waves in Newtonian or non-Newtonian fluid flows
- Transition to turbulence

Communications will focus on aspects such as:
- Description of the mechanisms of the instabilities and their modeling (linear and non-linear equations, analogies, ...),
- Description of the patterns induced by instabilities or during the transition to turbulence.

Theoretical, numerical, and experimental approaches could be considered in the Taylor-Couette and Taylor-Dean flows as well as in other related flows.