The Varieties of Dynamic Multiscaling in Fluid Turbulence
نویسنده
چکیده
We show that different ways of extracting time scales from time-dependent velocity structure functions lead to different dynamic-multiscaling exponents in fluid turbulence. These exponents are related to equal-time multiscaling exponents by different classes of bridge relations which we derive. We check this explicitly by detailed numerical simulations of the GOY shell model for fluid turbulence. Our results can be generalized to any system in which both equal-time and timedependent structure functions show multiscaling.
منابع مشابه
The Universality of Dynamic Multiscaling in Homogeneous, Isotropic Turbulence
We systematise the study of dynamic multiscaling of time-dependent structure functions in different models of passive-scalar and fluid turbulence. We show that, by suitably normalising these structure functions, we can eliminate their dependence on the origin of time at which we start our measurements and that these normalised structure functions yield the same linear bridge relations that rela...
متن کاملDynamic multiscaling in magnetohydrodynamic turbulence.
We present a study of the multiscaling of time-dependent velocity and magnetic-field structure functions in homogeneous, isotropic magnetohydrodynamic (MHD) turbulence in three dimensions. We generalize the formalism that has been developed for analogous studies of time-dependent structure functions in fluid turbulence to MHD. By carrying out detailed numerical studies of such time-dependent st...
متن کاملDynamic multiscaling in two-dimensional fluid turbulence.
We obtain, by extensive direct numerical simulations, time-dependent and equal-time structure functions for the vorticity, in both quasi-Lagrangian and Eulerian frames, for the direct-cascade regime in two-dimensional fluid turbulence with air-drag-induced friction. We show that different ways of extracting time scales from these time-dependent structure functions lead to different dynamic-mult...
متن کاملScaling properties of the cosmic background plasma and radiation
Scaling properties of the cosmic microwave background (CMB) radiation are studied using satellite (COBE-DMR maps), balloonborne and ground-based (combined QMASK map) data. Quantitative consistency is found between the multiscaling properties of the COBE-DMR and QMASK CMB maps. Surprisingly, it is found that the observed CMB temperature multiscaling resembles quantitatively the multiscaling prop...
متن کاملMultiscaling in Models of Magnetohydrodynamic Turbulence
From a numerical study of the magnetohydrodynamic (MHD) equations we show, for the first time in three dimensions sd 3d, that velocity and magnetic-field structure functions exhibit multiscaling, extended self-similarity (ESS), and generalized extended self-similarity (GESS). We propose a new shell model for homogeneous and isotropic MHD turbulence, which preserves all the invariants of ideal...
متن کامل