A statistical state dynamics approach to wall turbulence.

摘要: This paper reviews results obtained using statistical state dynamics (SSD) that demonstrate the benefits of adopting this perspective for understanding turbulence in wall-bounded shear flows. The SSD approach used work employs a second-order closure retains only interaction between streamwise mean flow and perturbation covariance. restricts nonlinearity to explicitly retained constant together with nonlinear interactions dynamical restriction, which explicit perturbation–perturbation is removed from equation, simplified referred as restricted (RNL) dynamics. RNL systems, finite ensemble realizations equation share same flow, provide tractable approximations SSD, equivalent an infinite system. system, stochastic structural stability theory introduces new analysis tools studying turbulence. systems computationally efficient means approximate produce self-sustaining exhibiting qualitative features similar those observed direct numerical simulations despite greatly presented show can be supported by few single varying component interacting judicious selection truncated support or ‘band-limiting’ improve quantitative accuracy These suggest provides analytical computational allow insights into wall article part themed issue ‘Toward development high-fidelity models at large Reynolds number’.