The interaction between synoptic eddy and low-frequency flow (SELF) has been recognized for decades to play an important role in the dynamics of the low-frequency variability of the atmospheric circulation. In this three-part study a linear framework with a stochastic basic flow capturing both the climatological mean flow and climatological measures of the synoptic eddy flow is proposed. Based ...

Large-eddy simulation (LES) seeks to predict the dynamics of spatially filtered turbulent flows. By construction, the LES solution contains only scales of size ≥ ∆, where ∆ denotes some user-chosen length scale of the spatial filter. A large-eddy simulation based on an eddy-viscosity model and a Navier-Stokes simulation differ only in diffusion coefficient. Therefore, we focus on the question: ...

Turbulent flow over wall-mounted cube in a channel was investigated numerically using Large Eddy Simulation. The Selective Structure Function model was used to determine eddy viscosity that appeared in the subgrid scale stress terms in momentum equations. Studies were carried out for the flows with Reynolds number ranging from 1000 to 40000. To evaluate the computational results, data was compa...

Characteristics of rotor blade tip clearance flow in axial compressors can significantly affect their performance and stable operation. It may also increase blade vibrations and cause detrimental noises. Therefore, this paper is contributed to investigate tip leakage flow in a low speed isolated axial compressor rotor blades row. Simulations are carried out on near-stall condition, which is val...

A study of the interaction between vertical eddy heat fluxes and the vertical temperature structure of the mid-latitude troposphere is presented, guided by the hypothesis that a tendency of baroclinically unstable eddies to stabilize the zonal mean flow should be visible in the observed time-averaged zonal mean flow, the baroclinic adjustment hypothesis. Vertical temperature profiles in a conti...

During the Austral summer of 2006–07 a series of extreme oceanic events occurred in the Tasman Sea. Following a series of strong wind-driven upwelling events, an intense cold-core eddy developed off Sydney, Australia. A data-assimilating, eddy-resolving ocean model is used to create a threedimensional time-varying reanalysis of these events. The reanalysis indicates that the cold anomalies asso...

[1] Both observations and high resolution numerical models show that the Southern Ocean circumpolar flow is concentrated in a large number (approximately 8 to 12) of narrow filamentary jets. It is shown here that coherent jets exhibit a range of low frequency variability, on timescales of months to years, that can lead to displacement and to intermittent formation and dissipation of jets. Using...

[1] Tropical instability waves (TIWs), prevailing in the tropical Pacific and Atlantic Oceans, interact with the lowfrequency oceanic flow. It is known that TIWs act as negative feedback to ENSO through a thermal process. In this study, we examine the dynamical eddy feedback of TIWs. We show that in terms of physical processes, the dynamical TIW feedback is very similar to the atmospheric synop...

The effect of the spanwise discretisation on numerical calculations of the turbulent flow around a circular cylinder is systematically assessed at a subcritical Reynolds number of 10000 in the frame of three-dimensional large-eddy simulation. The eddy-viscosity k-equation subgrid scale model is implemented to evaluate unsteady turbulent flow field. Large-eddy simulation is known to be a reliabl...