Separation of heavy particles in turbulence.
We study motion of small particles in turbulence when the particle relaxation time falls in the range of inertial time scales of the flow. Because of inertia, particles drift relative to the fluid. We demonstrate that the collective drift of two close particles makes them see local velocity increments fluctuate fast. This allows us to introduce Langevin description for separation dynamics. We describe the behavior of the Lyapunov exponent and give the analogue of Richardson's law for separation above viscous scale.
Fouxon
Itzhak
I
Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Horvai
Péter
P