Anisotropy of magnetohydrodynamic turbulence at low magnetic Reynolds number

• Published in: Physics of fluids (1994) 2005-12, Vol.17 (12), p.125105.1-125105.12
• Main Authors: Vorobev, Anatoliy, Zikanov, Oleg, Davidson, Peter A., Knaepen, Bernard
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Isotropic turbulence; homogeneous turbulence; Magnetohydrodynamics and electrohydrodynamics; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma turbulence; Turbulent flows, convection, and heat transfer; Waves, oscillations, and instabilities in plasmas and intense beams
• ISSN: 1070-6631; 1089-7666
• DOI: 10.1063/1.2140847

Turbulent fluctuations in magnetohydrodynamic flows are known to become anisotropic under the action of a sufficiently strong magnetic field. We investigate this phenomenon in the case of low magnetic Reynolds number using direct numerical simulations and large eddy simulations of a forced flow in a periodic box. A series of simulations is performed with different strengths of the magnetic field, varying Reynolds number, and two types of forcing, one of which is isotropic and the other limited to two-dimensional flow modes. We find that both the velocity anisotropy (difference in the relative amplitude of the velocity components) and the anisotropy of the velocity gradients are predominantly determined by the value of the magnetic interaction parameter. The effects of the Reynolds number and the type of forcing are much weaker. We also find that the anisotropy varies only slightly with the length scale.