Two-dimensional homogeneous isotropic fluid turbulence with polymer additives

Manifestations of drag reduction by polymer additives in decaying, homogeneous, isotropic turbulence.

The existence of drag reduction by polymer additives, well established for wall-bounded turbulent flows, is controversial in homogeneous, isotropic turbulence. To settle this controversy, we carry out a high-resolution direct numerical simulation of decaying, homogeneous, isotropic turbulence with polymer additives. Our study reveals clear manifestations of drag-reduction-type phenomena: On the...

Collision Statistics of Inertial Particles in Two-Dimensional Homogeneous Isotropic Turbulence with an Inverse Cascade

This study investigates the collision statistics of inertial particles in inverse-cascading two-dimensional (2D) homogeneous isotropic turbulence by means of a direct numerical simulation (DNS). A collision kernel model for small Stokes number (St) particles in 2D flows is proposed based on the model of Saffman & Turner (1956) (ST56 model). The DNS results agree with this 2D version of the ST56...

Decay of homogeneous two-dimensional quantum turbulence

Spinodal decomposition in homogeneous and isotropic turbulence.

We study the competition between domain coarsening in a symmetric binary mixture below critical temperature and turbulent fluctuations. We find that the coarsening process is arrested in the presence of turbulence. The physics of the process shares remarkable similarities with the behavior of diluted turbulent emulsions and the arrest length scale can be estimated with an argument similar to th...

Anomalous scaling in homogeneous isotropic turbulence

The anomalous scaling exponents ζn of the longitudinal structure functions Sn for homogeneous isotropic turbulence are derived from the Navier-Stokes equations by using field theoretic methods to develop a low energy approximation in which the Kolmogorov theory is shown to act effectively as a mean field theory. The corrections to the Kolmogorov exponents are expressed in terms of the anomalous...