Controlling the complex spatio-temporal dynamics underlying life-threatening cardiac
arrhythmias such as fibrillation is extremely difficult, because of the nonlinear interaction of …

Turbulent fluid flows are ubiquitous in nature and technology, and are mathematically
described by the incompressible Navier-Stokes equations. A hallmark of turbulence is …

Homogeneous shear flows with an imposed mean velocity U=Syx̂ are studied in a period
box of size L x ×L y ×L z , in the statistically stationary turbulent state. In contrast with …

The disorganized fluctuations of turbulence are crucial in the transport of particles or
chemicals 1 , 2 and could play a decisive role in the formation of rain in clouds 3 , the accretion …

The mixing of a passive scalar in the presence of a mean gradient is studied in three dimensions
by direct numerical simulations. The driving velocity field is either a solution of the three…

A three‐dimensional adaptive mesh code is used to search for singularities in the incompressible
Euler equations. For the initial conditions examined, the maximum vorticity eventually …

The effect of turbulence on the collision rate between droplets in clouds is investigated.
Because of their inertia, water droplets can be shot out of curved streamlines of the turbulent …

Collisions between particles suspended in a fluid play an important role in many physical
processes. As an example, collisions of microscopic water droplets in clouds are a necessary …

Fully turbulent flows are characterized by intermittent formation of very localized and intense
velocity gradients. These gradients can be orders of magnitude larger than their typical …

The dynamical behavior of a large one-dimensional system obeying the cubic complex
Ginzburg-Landau equation is studied numerically as a function of parameters near a supercritical …