Stochastic coherent adaptive large eddy simulation SCALES is an extension of the large eddy simulation approach in which a wavelet filter-based dynamic grid adaptation strategy is employed to solve for the most “energetic” coherent structures in a turbulent field while modeling the effect of the less energetic background flow. In order to take full advantage of the ability of the method in simu...

We periodically modulate a turbulent wind-tunnel flow with an active grid. We find a resonant enhancement of the mean turbulent dissipation rate at a modulation frequency which equals the large-eddy turnover rate. Thus, we find the best frequency to inject energy into a turbulent flow. The resonant response is characterized by the emergence of vortical structures in the flow and depends on the ...

In this study, we investigate the problems of inhomogeneous turbulence. The main goal has been to find the connections between analytic turbulence theories, notably the formalism of the direct interaction approximation (DIA), and turbulence phenomenology. To simplify the results from an inhomogeneous DIA model, we have employed a diagonalization procedure and an assumption of weak inhomogeneity...

Observations of open-ocean deep convection indicate that it is a highly localized phenomenon, occurring over areas of tens of kilometers in diameter. The cause of this localization has been ascribed to ‘‘preconditioning’’— the local weakening of the stable density stratification associated with upwardly domed isopycnal surfaces in a surface-intensified cyclonic circulation. However, most numeri...

The nonlinear shallow-water equations are used to study the tropical stationary wave response to steady thermal forcing near the equator in earthlike zonally symmetric basic states. A thin (200 m) fluid layer is superimposed over a large (1500 m) zonally symmetric topography distribution that decreases smoothly from the Tropics to the Poles, thus providing the large meridional height gradients ...

Compensation of the poleward eddy heat transport by the heat transport of an eddy-induced mean meridional overturning cell is a common feature in many eddyresolving ocean models. It has been ,argued that this is the result of the weak thermal driving of the ocean. As the actual air/sea coupling is scale dependent, it might be questioned whether the approximation of weak thermal driving is relev...

The " local-equilibrium " hypothesis that assumes a local balance between the viscous dissipation and the subgrid-scale dissipation at the same physical location in turbulent flow has been commonly used for turbulence modeling. For example, based on the local equilibrium hypothesis, Germano et al. (1991) and Moin et al. (1991) developed dynamic procedures for determining the model coefficients ...

A model for the kinematic eddy viscosity has been developed which accounts for the turbulence produced as a result of jet interactions between adjacent streams as well as the turbulence initially present in the streams. In order to describe the turbulence contribution from jet interaction, the eddy viscosity suggested by Prandtl has been adopted, and a modification has been introduced to accoun...