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We apply the mathematical formalism of vector spherical harmonics decomposition to convective stellar velocity fields from multi-dimensional hydrodynamics simulations, and show that the resulting power spectra furnish a robust and stable…

Solar and Stellar Astrophysics · Physics 2015-06-19 Emmanouil Chatzopoulos , Carlo Graziani , Sean M. Couch

We use continuous wavelet transform techniques to construct the global and environment-dependent wavelet statistics, such as energy spectrum and kurtosis, to study the fluctuation and intermittency of the turbulent motion in the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-10 Yun Wang , Ping He

We investigate experimentally phenomenon of turbulent thermal diffusion of micron-size solid particles in an inhomogeneous convective turbulence forced by one vertically-oriented oscillating grid in an air flow. This effect causes formation…

Fluid Dynamics · Physics 2024-04-19 E. Elmakies , O. Shildkrot , N. Kleeorin , A. Levy , I. Rogachevskii

We discuss a recent experiment in which the spectrum of the vortex line density fluctuations has been measured in superfluid turbulence. The observed frequency dependence of the spectrum, $f^{-5/3}$, disagrees with classical vorticity…

Other Condensed Matter · Physics 2012-02-14 Philippe-Emmanuel P. -E. Roche , Carlo F. Barenghi

We develop the formulation of turbulence in terms of the functional integral over the phase space configurations of the vortex cells. The phase space consists of Clebsch coordinates at the surface of the vortex cells plus the Lagrange…

High Energy Physics - Theory · Physics 2008-02-03 A. A. Migdal

We have investigated the degree to which turbulence in the Very Local Interstellar Clouds resembles the highly-studied turbulence in the solar corona and the solar wind. The turbulence diagnostics for the Local Clouds are the absorption…

Astrophysics of Galaxies · Physics 2015-05-28 Steven R. Spangler , Allison H. Savage , Seth Redfield

Turbulence in curved spacetimes in general, and in the vicinity of black holes (BHs) in particular, represents a poorly understood phenomenon that is often analysed employing techniques developed for flat spacetimes. We here propose a novel…

General Relativity and Quantum Cosmology · Physics 2025-11-19 Rita Megale , Alejandro Cruz-Osorio , Giuseppe Ficarra , Mario Imbrogno , Claudio Meringolo , Leonardo Primavera , Luciano Rezzolla , Sergio Servidio

In recent years, scale-by-scale energy transport in wall turbulence has been intensively studied, and the complex spatial and interscale transfer of turbulent energy has been investigated. As the enhancement of heat transfer is one of the…

Fluid Dynamics · Physics 2022-06-01 Takuya Kawata , Takahiro Tsukahara

The velocity fluctuations for point vortex models are studied for the {\alpha}-turbulence equations, which are characterized by a fractional Laplacian relation between active scalar and the streamfunction. In particular, we focus on the…

Fluid Dynamics · Physics 2019-09-11 Giovanni Conti , Gualtiero Badin

The elementary structures of turbulence, i.e., vortex tubes, are studied using velocity data obtained in laboratory experiments for boundary layers and duct flows at microscale Reynolds numbers 332-1934. While past experimental studies…

Fluid Dynamics · Physics 2009-11-13 H. Mouri , A. Hori

We examine the efficacy of streamwise traveling waves generated by a zero-net-mass-flux surface blowing and suction for controlling the onset of turbulence in a channel flow. For small amplitude actuation, we utilize weakly nonlinear…

Fluid Dynamics · Physics 2011-11-29 Rashad Moarref , Mihailo R. Jovanović

The decay of homogeneous isotropic turbulence in a variable viscosity fluid with a viscosity ratio up to 15 is analyzed by means of highly resolved direct numerical simulations (DNS) at low Reynolds numbers. The question addressed by the…

Fluid Dynamics · Physics 2018-09-21 Michael Gauding , Luminita Danaila , Emilien Varea

Measurements of the energy spectrum and of the vortex-density fluctuation spectrum in superfluid turbulence seem to contradict each other. Using a numerical model, we show that at each instance of time the total vortex line density can be…

Other Condensed Matter · Physics 2014-11-05 Andrew W. Baggaley , Jason Laurie , Carlo F. Barenghi

Vortical structures of turbulence, i.e., vortex tubes and sheets, are studied using one-dimensional velocity data obtained in laboratory experiments for duct flows and boundary layers at microscale Reynolds numbers from 332 to 1934. We…

Fluid Dynamics · Physics 2009-11-13 H. Mouri , A. Hori , Y. Kawashima

We study the effect of dust absorption on the recovery velocity and density spectra as well as on the anisotropies of magnetohydrodynamic turbulence using the Velocity Channel Analysis (VCA), Velocity Coordinate Spectrum (VCS) and Velocity…

Astrophysics of Galaxies · Physics 2017-08-11 D. Kandel , A. Lazarian , D. Pogosyan

Direct measurements of the velocity in turbulent convection of $SF_6$ near its gas-liquid critical point by light scattering on the critical density fluctuations were conducted. The temperature, velocity and cross frequency power spectra in…

chao-dyn · Physics 2009-10-31 Shay Ashkenazi , Victor Steinberg

On their roller coaster ride through turbulence, tracer particles sample the fluctuations of the underlying fields in space and time. Quantitatively relating particle and field statistics remains a fundamental challenge in a large variety…

Fluid Dynamics · Physics 2018-01-10 Cristian C. Lalescu , Michael Wilczek

We propose and validate a novel experimental technique to measure two-point statistics of turbulent flows. It consists in spreading rigid fibers in the flow and tracking their position and orientation in time and therefore been named…

In this paper we present the results of the statistical analysis of high-latitude HI turbulence in the Milky Way. We have observed HI in the 21 cm line, obtained with the Arecibo L-Band Feed Array (ALFA) receiver at the Arecibo radio…

Astrophysics · Physics 2014-10-13 A. Chepurnov , A. Lazarian , S. Stanimirovic , C. Heiles , J. E. G. Peek

We formulate and implement the Euler equations with SGS dynamics and provide numerical tests of an SGS turbulence energy model that predicts the turbulent pressure of unresolved velocity fluctuations and the rate of dissipation for highly…

Astrophysics of Galaxies · Physics 2015-05-20 W. Schmidt , C. Federrath