Kraichnan like model of turbulence with stratification

TL;DR

This paper introduces a generalized Kraichnan turbulence model that incorporates stratification effects, anisotropy, and compressibility, providing insights into boundary layer structures and scalar transport in atmospheric flows.

Contribution

It extends the Kraichnan model to include stratification and anisotropy, accounting for compressibility and density effects in turbulent flows.

Findings

Model captures vertical anisotropy in stratified turbulence

Predicts boundary layer-like structures in flow statistics

Discusses anomalous scaling in passive scalar and particle transport

Abstract

A generalization to the Kraichnan gaussian, white noise in time model of turbulent velocity field is proposed. The generalization is designed to take into account the effects of stratification in the atmospheric boundary layer by introducing different scaling exponents for horizontal and vertical velocity components, leading to strong vertical anisotropy. The inevitable compressibility of the model leads one to take into account also the density statistics of the fluid, which will immediately lead to a boundary layer like structure in the flow statistics and non zero time correlations. Possible applications for passive scalar, tracer and inertial particle statistics and their anomalous scaling behavior will be discussed.