A modification of Kraichnan’s direct interaction approximation (DIA) [R. H. Kraichnan, J. Math. Phys. 2, 124 (1961)] for random linear partial differential equations is proposed. The approximation is tested on the specific example of the turbulent advection of a scalar quantity by a random velocity field. It is shown to account for the sweeping more correctly than the DIA. As a result, it is valid for all times and it is able to describe nonstandard diffusive processes (i.e., superdiffusive and non-Gaussian) for which the DIA is not valid.
|Original language||English (US)|
|Journal||Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics|
|State||Published - 1998|
ASJC Scopus subject areas
- Statistical and Nonlinear Physics
- Statistics and Probability
- Condensed Matter Physics