A second-order modelling of a stably stratified sheared turbulence submitted to a non-vertical shear

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

“…3-(a) model 1, 3-(b) model 2; 3-( Three models indicate also that (b 12 ) οο grows with Ri growing from weak stratification (Ri=0.05) to strong stratification (Ri=3.0). This result is not in contradiction with our previous results (Bouzaiane et al (2004)). We note also that the asymptotic equilibrium state for the model 1 and the model 2 are reached very quickly compared to the prediction of the model 3 which predict an equilibrium state from St=τ=48.…”

“…Here, terms noted 1 are terms of return to the isotropy, they characterize the non linear mechanism of interaction between turbulent fluctuations. The terms 2 represent the interaction between mean and turbulent flows, they characterize the linear terms .Finally, the terms 3 are terms due to buoyancy effects (Bouzaiane et al (2004)). During the two past decades several models have been presented by authors.…”

“…For example a turbulent flow tends to qualify a state of agitation of the movement where speeds move in a way apparently irregular, disordered and chaotic. In order to envisage the behavior of the turbulent flows, and for understanding well the complex turbulent processes of geophysics flows in the atmosphere and oceans, several authors (Holt et al (1992) and Jacobitz et al (1997) were interested to the analysis of different aspects of the coupled effects of a stable stratification (Bouzaiane et al (2003b)) and a shear for a homogeneous turbulence. During the last years, Gerz et al (1989) were interested to the study of the direct digital simulations for a homogeneous turbulence submitted to a vertical shear.…”

On the Turbulent Prandtl Number in Stably Stratified Turbulence by Second Order Models

“…The classic second order model of Launder, Reece and Rodi (LRR) [12] in one hand and the sophisticated model of Craft and Launder (CL) [13] have been retained. For its success in many different applications of stratified homogeneous shear flow [8][9][10], the Zeman Lumley model is retained for the third contributions of the pressure strain correlation and pressure scalar gradient correlation:…”

“…The second order modeling of stratified homogeneous turbulence remains to our sense an important approach of studying homogeneous turbulence since its application to the great number of engineering flows and industrial applications [6][7]. In a previous work, we are interested to the prediction of equilibrium states in stratified homogenous turbulence with vertical or inclined shear [8][9]. We were focused essentially to the asymptotic behavior of dimensionless kinematic parameters such as the component of the anisotropic tensor and the non dimensional shear number  KS .…”