2005/01/03 by Antonio Celani, Agnese Seminara · 20 citations
Earth and Planetary Sciences · Engineering · Mathematics · Physics and Astronomy · #Classical mechanics #Cosmology and Gravitation Theories #Fluid Dynamics and Turbulent Flows #Geometry #Materials science #Mathematics #Mechanics #Meteorological Phenomena and Simulations #Physics #Quantum mechanics #Range (aeronautics) #Scalar (mathematics) #Scalar field #Scale (ratio) #Statistical physics #Turbulence #Vector field #nlin.CD
paper · pdf · doi:10.1103/physrevlett.94.214503
published in Physical Review Letters 94(21), 214503 (American Physical Society) · 4 pages, 6 figures
arxiv created 2005/01/03 · openalex publication_date 2005/06/03 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the large-scale statistics of a passive scalar transported by a turbulent velocity field by means of direct numerical simulations. We focus on scales larger than the characteristic length scale of scalar injection, yet smaller than the correlation length of the velocity. We show the existence of nontrivial long-range correlations in the form of new power laws for the decay of high-order coarse-grained scalar cumulants. This result contradicts the classical scenario of Gibbs equilibrium statistics that should hold in the absence of scalar flux. The breakdown of "thermal equilibrium" at large scales is traced back to the statistical geometry of turbulent dispersion of two scalar blobs. The numerical values obtained for the scaling exponents of the coarse-grained scalar cumulants are in agreement with recent theoretical results.