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Related papers: Kazantsev dynamo in turbulent compressible flows

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The growth of the density fluctuations is considered to be an important cosmological test. In the standard model, for a matter dominated universe, the growth of the density perturbations evolves with redshift z like (1/{1+z))^s with s=1.…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-17 Andre Maeder , Vesselin G. Gueorguiev

We revisit the issue of whether thermal fluctuations are relevant for incompressible fluid turbulence, and estimate the scale at which they become important. As anticipated by Betchov in a prescient series of works more than six decades…

Fluid Dynamics · Physics 2021-11-18 Gregory Eyink , Dmytro Bandak , Nigel Goldenfeld , Alexei A. Mailybaev

High Reynolds number isotropic magneto-hydro-dynamic turbulence in the presence of large scale magnetic fields is investigated as a function of the magnetic field strength. For a variety of flow configurations the energy dissipation rate…

Fluid Dynamics · Physics 2012-09-20 Alexandros Alexakis

Fluctuating hydrodynamics provides a model for fluids at mesoscopic scales where thermal fluctuations can have a significant impact on the behavior of the system. Here we investigate a model for fluctuating hydrodynamics of a single…

Fluid Dynamics · Physics 2015-06-22 Anuj Chaudhri , John B. Bell , Alejandro L. Garcia , Aleksandar Donev

The fluctuating hydrodynamics by Brey et. al. is analytically solved to get the long-time limit of the fluctuations of the number density, velocity field, and energy density around the homogeneous cooling state of a granular gas, under…

Statistical Mechanics · Physics 2023-11-27 Jesús David Jiménez Oliva , Pablo Rodriguez-Lopez , Nagi Khalil

Using direct numerical simulations, we verify that "flow IV" of Roberts (1972) exhibits dynamo action dominated by horizontally averaged large-scale magnetic field. With the test-field method we compute the turbulent magnetic diffusivity…

Solar and Stellar Astrophysics · Physics 2013-08-09 Ebru Devlen , Axel Brandenburg , Dhrubaditya Mitra

Radio-wave scintillation observations reveal a nearly Kolmogorov spectrum of density fluctuations in the ionized interstellar medium. Although this density spectrum is suggestive of turbulence, no theory relevant to its interpretation…

Astrophysics · Physics 2009-11-06 Yoram Lithwick , Peter Goldreich

We study the dynamics of neutrally buoyant particles with diameters varying in the range [1, 45] in Kolmogorov scale units (eta) and Reynolds numbers based on Taylor scale between 580 and 1050. One component of the particles' velocity is…

Fluid Dynamics · Physics 2011-09-02 Romain Volk , Enrico Calzavarini , Emmanuel Leveque , Jean-Francois Pinton

Large-scale compressive slow-mode-like fluctuations can cause variations in the density, temperature, and magnetic-field magnitude in the solar wind. In addition, they also lead to fluctuations in the differential flow $U_{\rm p\alpha}$…

Space Physics · Physics 2023-08-07 Xingyu Zhu , Daniel Verscharen , Jiansen He , Bennett A. Maruca , Christopher J. Owen

From a simple path integral involving a variable volatility in the velocity differences, we obtain velocity probability density functions with exponential tails, resembling those observed in fully developed turbulence. The model yields…

chao-dyn · Physics 2009-10-28 B. Holdom

A large number of models which address the dynamics of particle-laden turbulent flows have been developed based on the assumption of local isotropy and use the Kolmogorov constant that correlates the spectral distribution of turbulent…

Fluid Dynamics · Physics 2022-10-26 Naveen Rohilla , Partha S Goswami

We numerically investigate the efficiency of a spherical Couette flow at generating a self-sustained magnetic field. No dynamo action occurs for axisymmetric flow while we always found a dynamo when non-axisymmetric hydrodynamical…

Geophysics · Physics 2020-07-17 Céline Guervilly , Philippe Cardin

Measurements of local density fluctuations are crucial to characterizing the interfacial properties of equilibrium fluids. A specific case that has been well-explored involves the heightened compressibility of water near hydrophobic…

Soft Condensed Matter · Physics 2024-02-09 Nigel B. Wilding , Robert Evans , Francesco Turci

We present the results of an ensemble of SPH simulations that follow the evolution of prestellar cores for $0.2\,{\rm Myr}$. All the cores have the same mass, and start with the same radius, density profile, thermal and turbulent energy.…

Solar and Stellar Astrophysics · Physics 2015-06-23 O. Lomax , A. P. Whitworth , D. A. Hubber

In the standard cascade picture of 3D turbulent fluid flows, energy is input at a constant rate at large scales. Energy is then transferred to smaller scales by an intermittent process that has been the focus of a vast literature. However,…

Fluid Dynamics · Physics 2015-06-16 Chen-Chi Chien , Daniel B. Blum , Greg A. Voth

The original goal of Large Eddy Simulations of fully developed turbulent flows was to accurately describe large-scale flow features ${\bf u}(\Delta)$ at the scales $r\geq \Delta$ where $\Delta$ is a size of computational mesh. The effect of…

Fluid Dynamics · Physics 2011-09-29 Victor Yakhot , John Wanderer

Large scale molecular dynamics simulations of freely decaying turbulence in three-dimensional space are reported. Fluid components are defined from the microscopic states by eliminating thermal components from the coarse-grained fields. The…

Statistical Mechanics · Physics 2014-03-14 Teruhisa S. Komatsu , Shigenori Matsumoto , Takashi Shimada , Nobuyasu Ito

Multidimensional cosmological models with a higher dimensional space-time manifold are investigated under dimensional reduction. In the Einstein conformal frame, the effective potential for the internal scale factors is obtained. The stable…

General Relativity and Quantum Cosmology · Physics 2007-05-23 U. Guenther , S. Kriskiv , A. Zhuk

We study the saturation of three-dimensional unstable perturbations on a fast rotating turbulent flow using direct numerical simulations (DNSs). Under the effect of Kolmogorov forcing, a transition between states dominated by coherent…

The role of compressible fluctuations in the energy cascade of fast solar wind turbulence is studied using a reduced form of an exact law derived recently (Banerjee and Galtier, PRE, 2013) for compressible isothermal magnetohydrodynamics…

Space Physics · Physics 2016-10-05 Supratik Banerjee , Lina Z. Hadid , Fouad Sahraoui , Sebastien Galtier