Since the seminal studies by Osborne Reynolds in the nineteenth century, pipe flow has
served as a primary prototype for investigating the transition to turbulence in wall-bounded …

Active matter extracts energy from its surroundings at the single particle level and transforms
it into mechanical work. Examples include cytoskeleton biopolymers and bacterial …

Turbulent flows are characterized by the non-linear cascades of energy and other inviscid
invariants across a huge range of scales, from where they are injected to where they are …

Simulations and experiments at low Reynolds numbers have suggested that skin-friction
drag generated by turbulent fluid flow over a surface can be decreased by oscillatory motion …

Various types of structures self-organised by animals exist in nature, such as bird flocks and
insect swarms, which stem from the local communications of vast numbers of limited …

Wall-bounded turbulence exhibits patterns that persist in time and space: coherent
structures. These are important for transport processes and form a conceptual framework for …

These lecture notes are based on a tutorial given in 2017 at a plasma physics winter school
in Les Houches. Their aim is to provide a self-contained graduate-student level introduction …

Developing microscale sensors capable of force measurements down to the scale of
piconewtons is of fundamental importance for a wide range of applications. To date …

The route to turbulence in pipe flow is a complex, nonlinear, spatiotemporal process for
which an increasingly clear understanding has emerged in recent years. This paper …

Turbulence is one of the most frequently encountered non-equilibrium phenomena in
nature, yet characterizing the transition that gives rise to turbulence in basic shear flows has …