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Two types of spontaneous breaking of the space translational symmetry in distributed chaos have been considered for turbulent thermal convection at large values of Rayleigh number. First type is related to boundaries and second type is…

Fluid Dynamics · Physics 2016-10-19 A. Bershadskii

The coexistence of motions on various scales is a remarkable feature of solar convection, which should be taken into account in analyses of the dynamics of magnetic fields. Therefore, it is important to investigate the factors responsible…

Solar and Stellar Astrophysics · Physics 2015-01-15 O. V. Shcheritsa , A. V. Getling , O. S. Mazhorova

We report on simulations of mildly turbulent convection in spherical wedge geometry with varying density stratification. We vary the density contrast within the convection zone by a factor of 20 and study the influence of rotation on the…

Solar and Stellar Astrophysics · Physics 2012-04-25 P. J. Käpylä , M. J. Mantere , A. Brandenburg

In this note we advocate the notion of variety as juxtaposed to the notion of complexity. Laminar flows are complex, turbulence is various. When the gradients reach a critical point, laminar flows are subjected to instabilities and…

Fluid Dynamics · Physics 2021-03-30 Massimo Germano

We demonstrate that at long times the rate of passive scalar decay in a turbulent, or simply chaotic, flow is dominated by regions (in real space or in inverse space) where mixing is less efficient. We examine two situations. The first is…

Chaotic Dynamics · Physics 2009-11-07 M. Chertkov , V. Lebedev

The gas motions in the intracluster medium (ICM) are governed by stratified turbulence. Stratified turbulence is fundamentally different from Kolmogorov (isotropic, homogeneous) turbulence; kinetic energy not only cascades from large to…

Astrophysics of Galaxies · Physics 2020-03-26 Rajsekhar Mohapatra , Christoph Federrath , Prateek Sharma

The spectrum of turbulence in superfluid liquid is modified by the nonlinear energy dissipation caused by the mutual friction between quantized vortices and the normal component of the liquid. In some region of two Reynolds parameters…

Chaotic Dynamics · Physics 2009-11-10 Victor S. L'vov , Sergey V. Nazarenko , Grigory E. Volovik

Following recent evidence that the vortices in decaying two-dimensional turbulence can be classified into small--mobile, and large--quasi-stationary, this paper examines the evidence that the latter might be considered a `crystal' whose…

Fluid Dynamics · Physics 2021-08-04 Javier Jiménez

Spatial buoyancy-helical distributed chaos (turbulence) in the cumulus, stratiform, stratocumulus, cirrus and cirrus mammatus clouds have been studied using results of direct numerical simulations and measurements in cloudy atmosphere. It…

Atmospheric and Oceanic Physics · Physics 2021-04-14 A. Bershadskii

The breaking of detailed balance, the symmetry between forward and backward probability transition between two states, is crucial to understand irreversible systems. In hydrodynamic turbulence, a far-from equilibrium system, we observe a…

It is shown that helicity dynamics dominates spectral distribution of the velocity fluctuations in turbulent thermal convection at moderate and large values of the Rayleigh number (distributed chaos and scaling respectively). The…

Fluid Dynamics · Physics 2020-04-29 A. Bershadskii

In channel flows a step on the route to turbulence is the formation of streaks, often due to algebraic growth of disturbances. While a variation of viscosity in the gradient direction often plays a large role in laminar-turbulent transition…

Fluid Dynamics · Physics 2007-05-23 Vijayakumar Chikkadi , A. Sameen , Rama Govindarajan

We show that the phase space of stratified turbulence mainly consists of two slow invariant manifolds with rich physics, embedded on a larger basin with fast evolution. A local invariant manifold in the vicinity of the fluid at equilibrium…

Fluid Dynamics · Physics 2019-12-09 Nicolas E. Sujovolsky , Pablo D. Mininni

What features characterise complex system dynamics? Power laws and scale invariance of fluctuations are often taken as the hallmarks of complexity, drawing on analogies with equilibrium critical phenomena[1-3]. Here we argue that slow,…

Statistical Mechanics · Physics 2007-05-23 Paul Anderson , Henrik Jeldtoft Jensen , L. P. Oliveira , Paolo Sibani

Turbulence, namely, irregular fluctuations in space and time characterize fluid flows in general and atmospheric flows in particular.The irregular,i.e., nonlinear space-time fluctuations on all scales contribute to the unpredictable nature…

General Physics · Physics 2007-05-23 J. S. Pethkar , A. M. Selvam

A numerical study of decaying stably-stratified flows is performed. Relatively high stratification and moderate Reynolds numbers are considered, and a particular emphasis is placed on the role of helicity (velocity-vorticity correlations).…

Fluid Dynamics · Physics 2015-06-12 C. Rorai , D. Rosenberg , A. Pouquet , P. D. Mininni

Chaos is widely understood as being a consequence of sensitive dependence upon initial conditions. This is the result of an instability in phase space, which separates trajectories exponentially. Here, we demonstrate that this criterion…

Chaotic Dynamics · Physics 2017-06-28 Marc Pradas , Alain Pumir , Greg Huber , Michael Wilkinson

Multiple chaotic and turbulent regimes in Rayleigh-B\'{e}nard convection have been studied and classified from the onset of deterministic chaos to the fully developed turbulence using the distributed chaos approach supported by results of…

Fluid Dynamics · Physics 2019-12-24 A. Bershadskii

The inertia of particles driven by the turbulent flow of the surrounding fluid makes them prefer certain regions of the flow. The heavy particles lag behind the flow and tend to accumulate in the regions with less vorticity, while the light…

Chaotic Dynamics · Physics 2015-05-30 Itzhak Fouxon

In this paper, the properties of stably stratified turbulence (SST) and turbulent thermal convection are contrasted. A key difference between these flows is the sign of the kinetic energy feed by buoyancy, $\mathcal{F}_B$. For SST,…

Fluid Dynamics · Physics 2019-05-22 Mahendra K. Verma