Energy cascades in rapidly rotating and stratified turbulence within elongated domains

Abstract

We study forced, rapildy rotating and stably stratified turbulence in an elongated domain using an asymptotic expansion at simultaneously low Rossby number $Ro\ll 1$ and large domain height compared to the energy injection scale, $h=H/{\ell }_{in}\gg 1$. The resulting equations depend on the parameter $\lambda =(hRo{)}^{-1}$ and the Froude number $Fr$. An extensive set of direct numerical simulations (DNS) is performed to explore the parameter space $(\lambda ,Fr)$. We show that a forward energy cascade occurs in one region of this space, and a split energy cascade outside it. At weak stratification (large $Fr$), an inverse cascade is observed for sufficiently large $\lambda$. At strong stratification (small $Fr$) the flow becomes approximately hydrostatic and an inverse cascade is always observed. For both weak and strong stratification, we present theoretical arguments supporting the observed energy cascade phenomenology. Our results shed light on an asymptotic region in the phase diagram of rotating and stratified turbulence, which is difficult to attain by brute-force DNS.

References in corpus (12)

• Inverse cascade and symmetry breaking in rapidly-rotating Boussinesq convection
• Large-scale vortices in rapidly rotating Rayleigh-Bénard convection
• Evidence for Bolgiano-Obukhov scaling in rotating stratified turbulence using high-resolution direct numerical simulations
• Large-scale anisotropy in stably stratified rotating flows
• Rotating Taylor-Green Flow
• Dual constant-flux energy cascades to both large scales and small scales
• On the edge of an inverse cascade
• Split energy cascade in turbulent thin fluid layers
• Dimensional transition of energy cascades in stably stratified thin fluid layers
• Jets and large-scale vortices in rotating Rayleigh-Bénard convection
• Vortical and Wave Modes in 3D Rotating Stratified Flows: Random Large Scale Forcing
• Role of the forcing dimensionality in thin-layer turbulent energy cascades

Cited by in corpus (4)

• Geometric microcanonical theory of two-dimensional Truncated Euler flows
• Inverse cascade suppression and shear layer formation in MHD turbulence subject to a guide field and misaligned rotation
• Scale-by-scale kinetic energy flux calculations in simulations of rotating convection
• 2D Internal Gravity Wave Turbulence