Models of intermittency in hydrodynamic turbulence
Abstract
A heurisitic model for evolution of the probability distribution (PDF) of transverse velocity gradient s in incompressible NavierStokes turbulence is distilled from an analytical closure for Burgers turbulence. At all Reynolds number scrR, the evolved PDF is ~s^{1/2} exp(const×s/<s^{2}>^{1/2}) for large s. The model suggests that skewness and flatnesses are asymptotically independent of scrR, and that cascade to smaller scales is not a fractal process. For Burgers dynamics, both simulations and the analytical closure give a PDF ~ξ^{1} exp(const×ξ/<ξ^{2}>^{1/2}) for large negative velocity gradient ξ.
 Publication:

Physical Review Letters
 Pub Date:
 July 1990
 DOI:
 10.1103/PhysRevLett.65.575
 Bibcode:
 1990PhRvL..65..575K
 Keywords:

 Burger Equation;
 Computational Fluid Dynamics;
 Hydrodynamics;
 NavierStokes Equation;
 Probability Distribution Functions;
 Turbulent Flow;
 Heuristic Methods;
 Kolmogoroff Theory;
 Reynolds Number;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer;
 47.25.Cg;
 05.40.+j;
 05.45.+b