Statistical properties of freely decaying two-dimensional hydrodynamic turbulence

A coalescence model for freely decaying two-dimensional turbulence

– We propose a ballistic coalescence model (punctuated-Hamiltonian approach) mimicking the fusion of vortices in freely decaying two-dimensional turbulence. A temporal scaling behaviour is reached where the vortex density evolves like t. A mean-field analytical argument yielding the approximation ξ = 4/5 is shown to slightly overestimate the decay exponent ξ whereas Molecular Dynamics simulatio...

Decaying Two-dimensional Turbulence in Bounded Flows

Two-dimensional turbulence in unbounded or double periodic domains, in Navier-Stokes fluids and plasmas has been investigated intensively during the last decades by means of numerical simulations. The presence of an inertial range in the energy spectrum of these flows has been well documented. As two-dimensional flows exhibit an inverse cascade in the energy, coherent structures comparable with...

An ‘ideal’ form of decaying two-dimensional turbulence

Statistical properties of compressible hydrodynamic and magnetohydrodynamic turbulence

In this work, statistical properties of compressible hydrodynamic and magnetohydrodynamic turbulence are studied using direct numerical simulations. The properties of turbulent flows change when average flow velocities within the turbulence exceed the speed of sound in the medium. High flow velocities lead to the formation of shocks, and some of the base assumptions of turbulence theories of in...

Evolution of magnetic fields in freely decaying magnetohydrodynamic turbulence.

We study the evolution of magnetic fields in freely decaying magnetohydrodynamic turbulence. By quasilinearizing the Navier-Stokes equation, we solve analytically the induction equation in the quasinormal approximation. We find that, if the magnetic field is not helical, the magnetic energy and correlation length evolve in time, respectively, as E(B) proportional to t(-2(1+p)/(3+p)) and xi(B) p...