2014/07/17 by R. Marino, Raffaele Marino, P. D. Mininni +4 · 53 citations
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #Anisotropy #Cascade #Classical mechanics #Fluid Dynamics and Turbulent Flows #Geomagnetism and Paleomagnetism Studies #Isotropy #Kinetic energy #Mechanics #Optics #Physics #Quantum mechanics #Reynolds number #Scale (ratio) #Solar and Space Plasma Dynamics #Statistical physics #Stratification (seeds) #Stratified flow #Stratified flows #Turbulence #physics.flu-dyn
paper · pdf · doi:10.1103/physreve.90.023018
published in Physical Review E 90(2), 023018 (American Physical Society)
arxiv created 2014/07/17 · openalex publication_date 2014/08/28 · arxiv updated 2015/06/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up to 1024(3) grid points and Reynolds numbers of ≈1000. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the kinetic energy displays a perpendicular (horizontal) spectrum with power-law behavior compatible with ∼k(⊥)(-5/3), including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.