A Study of the Asymptotic Equilibrium Behavior in Stratified Turbulence Submitted to Horizontal Shear

Abstract

In this work, the asymptotic equilibrium behaviour of dimensionless parameters in stably stratified tu rbulence submitted to a horizontal shear is studied using tw o different methods. The first one is an analytic m ethod and is based on linear solutions obtained when non line ar effects of pressure and viscosity are neglected. The Laplace Transform is used for integrating different ial system. The principal result of this first part of our work is the existence of asymptotic equilibrium sta tes at high shear for all non dimensionless paramet ers. The second method is a numerical one and is based on a second-order modeling of equations. The Speziale Sarkar and Gatski (SSG) model is retained for pressure-str ain correlation and dissipation time evolution equa tion, whereas, three of the most known second-order models are retained for the scalar field. The principal result of this second part is the big contribution of the SSG models for predicting asymptotic equilibrium state s of non dimensional parameters.