Evaluation SSG-LRR Model on an Homogeneous Turbulence under Inclined Shear for High and Low Stratification: Shear Number Effect

Abstract

This chapter develops proposals for an evaluation coupled second order model of SSG-LRR on an homogeneous turbulence submitted to an inclined shear for high and low stratification. The effect of Shear number on thermal and dynamic turbulent fields of the problem is performed for Shear number fixed at 2, 6, 14 and 20. Two values of Froude number equal to 0.35 and 1.29 are adopted for all numerical simulations corresponding to high and low stratification, respectively. For all simulations, value of angle theta is fixed at θ = π/4 corresponding to the angle between the shear and the vertical gradient of stratification. SSG-LRR model is adopted to compute turbulent parameters of principal component of anisotropy b12, normalized turbulence dissipation ε/KS and the density flux ρu1¯. A good agreement is detected by comparison of findings via model of SSG-LRR with the reported results in the literature by Direct Numerical Simulation of Jacobitz (DNSJ). It is found that the variation of Shear number predict a very strong influence on thermal and dynamic turbulent characteristics. Hence, findings with SSG-LRR model prove the existence of an asymptotic equilibrium states for various thermal and dynamic parameters in particularly for a low stratification.