The effect of non-vertical shear on stratified turbulence using the coupling between second-order models

ABSTRACT

In the present investigation, the evolution of stratified turbulence submitted to a non-vertical shear is studied using second-order models. Different cases of turbulent flows are considered. Firstly, the case of a purely horizontal shear is considered ($\theta =\pi /2$). In the second case, we study a purely vertical shear $\theta =0$. Finally, we studied an inclined shear corresponding to $\theta =\pi /6,\theta =\pi /4,\theta =\pi /3,\pi /8,3\pi /8$. For various inclinations, angle θ, the evolution of the turbulence is investigated for a fixed Richardson number $Ri$ at 0.2 related to low stratification. However, we study the influence of shear inclination angle θ on the evolution of turbulence via the coupling between second-order models (SSG-SL, SSG-CL, and SSG-LRR). A good agreement between predictions of second-order models and those of Direct Numerical Simulation of Jacobitz is detected for the principal component of anisotropy $b_{12}$.

KEYWORDS:

• Stably stratified turbulence
• second-order models
• asymptotic equilibrium states
• non-vertical shear
• direct numerical simulation of Jacobitz (DNSJ)

Disclosure statement

No potential conflict of interest was reported by the authors.