Robustness of the inverse cascade in two-dimensional turbulence.

The Inverse Energy Cascade of Two-Dimensional Turbulence

Diminishing inverse transfer and non-cascading dynamics in surface quasi-geostrophic turbulence

The inverse transfer in two-dimensional turbulence governed by the surface quasigeostrophic (SQG) equation is studied. The nonlinear transfer of this system conserves the two quadratic quantities Ψ1 = 〈|(−∆) 1/4ψ|2〉/2 and Ψ2 = 〈|(−∆) 1/2ψ|2〉/2 (kinetic energy), where ψ is the streamfunction and 〈·〉 denotes a spatial average. In the limit of infinite domain, the kinetic energy density Ψ2 remains...

Inverse cascade regime in shell models of two-dimensional turbulence.

We consider shell models that display an inverse energy cascade similar to two-dimensional turbulence (together with a direct cascade of an enstrophylike invariant). Previous attempts to construct such models ended negatively, stating that shell models give rise to a "quasiequilibrium" situation with equipartition of the energy among the shells. We show analytically that the quasiequilibrium st...

Inverse energy cascade and emergence of large coherent vortices in turbulence driven by Faraday waves.

We report the generation of large coherent vortices via inverse energy cascade in Faraday wave driven turbulence. The motion of floaters in the Faraday waves is three dimensional, but its horizontal velocity fluctuations show unexpected similarity with two-dimensional turbulence. The inverse cascade is detected by measuring frequency spectra of the Lagrangian velocity, and it is confirmed by co...

Stall Vortex Shedding over a Compressor Cascade (RESEARCH NOTE)

The unstable flow with rotating-stall-like (RS) effects in a rotor-cascade of an axial compressor was numerically investigated. The RS was captured with the reduction in mass flow rate and increasing of exit static pressure with respect to design operating condition of the single rotor. The oscillatory velocity traces during the stall propagation showed that the RS vortices repeat periodically,...