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Intermittency in the isotropic component of helical and nonhelical turbulent flows
(American Physical Society, 2010-01)
We analyze the isotropic component of turbulent flows spanning a broad range or Reynolds numbers. The aim is to identify scaling laws and their Reynolds number dependence in flows under different mechanical forcings. To ...
Simulations of turbulent channels with prescribed velocity profiles
(Cambridge University Press, 2013-05)
Direct numerical simulations of turbulent channels with artificially prescribed velocity profiles are discussed, using both natural and purposely incorrect profiles. It is found that turbulence develops correctly when ...
Wave turbulence buildup in a vibrating plate
(Springer, 2015-10)
We report experimental and numerical results on the buildup of the energy spectrum in wave turbulence of a vibrating thin elastic plate. Three steps are observed: first a short linear stage, then the turbulent spectrum is ...
Friction factor for turbulent flow in rough pipes from Heisenberg's closure hypothesis
(American Physical Society, 2009-05)
We show that the main results of the analysis of the friction factor for turbulent pipe flow reported by Gioia and Chakraborty [Phys. Rev. Lett. 96, 044502 (2006)] can be recovered by assuming the Heisenberg closure ...
Instabilities; shocks and turbulence in space and astrophysical plasmas
(Asociación Argentina de Astronomía, 2018-10)
The dynamics of plasmas pervading the interplanetary and interstellar medium are often described within the frame of magnetohydrodynamics (MHD), which involves the coupling between flows and magnetic fields. This theoretical ...
Drag reduction by polymer additives from turbulent spectra
(American Physical Society, 2010-12)
We extend the analysis of the friction factor for turbulent pipe flow reported by G. Gioia and P. Chakraborty [Phys. Rev. Lett. 96, 044502 (2006)]10.1103/PhysRevLett.96.044502 to the case where drag is reduced by polymer ...
Helicity cascades in rotating turbulence
(American Physical Society, 2009-12)
The effect of helicity (velocity-vorticity correlations) is studied in direct numerical simulations of rotating turbulence down to Rossby numbers of 0.02. The results suggest that the presence of net helicity plays an ...
Rapid alignment of velocity and magnetic field in magnetohydrodynamic turbulence
(American Physical Society, 2008-12)
We show that local directional alignment of the velocity and magnetic field fluctuations occurs rapidly in magnetohydrodynamics for a variety of parameters and is seen both in direct numerical simulations and in solar wind ...
Alternative derivation of exact law for compressible and isothermal magnetohydrodynamics turbulence
(American Physical Society, 2017-11)
The exact law for fully developed homogeneous compressible magnetohydrodynamics (CMHD) turbulence is derived. For an isothermal plasma, without the assumption of isotropy, the exact law is expressed as a function of the ...
Turbulence characterization by studying laser beam wandering in a differential tracking motion setup
(Society of Photo-Optical Instrumentation Engineers, 2009-10-01)
The Differential Image Motion Monitor (DIMM) is a standard and widely used instrument for astronomical seeing measurements. The seeing values are estimated from the variance of the differential image motion over two equal ...