We re-examine the Boussinesq hypothesis of an effective turbulent viscosity within the context of simple closure considerations for models of strong magnetohydrodynamic turbulence. Reynolds-stress and turbulent Maxwell-stress closure models will necessarily introduce a suite of transport coefficients, all of which are to some degree model-dependent. One of the most important coefficients is the...

Turbulence of magnetohydrodynamic waves in nature and in the laboratory is generally cross-helical or nonbalanced, in that the energies of Alfvén waves moving in opposite directions along the guide magnetic field are unequal. Based on high-resolution numerical simulations it is proposed that such turbulence spontaneously generates a condensate of the residual energy E(v) - E(b) at small field-p...

The layout of the major components of the BPX poloidal field (PF) system is shown in Fig. 5.1. External to the toroidal field (TF) magnet and assembly are the seven updown symmetric pairs of primary PF-producing coils. These are called the external PF coils. They are labeled in pairs, with PFlU being the inner (small major radius) PF coil closest to and above the midplane and PFZU-PF7U proceedi...

In an electrically conducting fluid, vortices stretch out a weak, large-scale magnetic field to form strong current sheets on their edges. Associated with these current sheets are magnetic stresses, which are subsequently released through reconnection, leading to vortex disruption, and possibly even destruction. This disruption phenomenon is investigated here in the context of two-dimensional, ...

We present a study of the multiscaling of time-dependent velocity and magnetic-field structure functions in homogeneous, isotropic magnetohydrodynamic (MHD) turbulence in three dimensions. We generalize the formalism that has been developed for analogous studies of time-dependent structure functions in fluid turbulence to MHD. By carrying out detailed numerical studies of such time-dependent st...

We present a quantitative estimate of the anisotropic power and scaling of magnetic field fluctuations in inertial range magnetohydrodynamic turbulence, using a novel wavelet technique applied to spacecraft measurements in the solar wind. We show for the first time that, when the local magnetic field direction is parallel to the flow, the spacecraft-frame spectrum has a spectral index near 2. T...

Magnetohydrodynamic MHD flow of a RedOx electrolyte in a straight conduit is investigated theoretically. Inert electrodes are deposited along segments of the opposing walls of a straight conduit that is filled with a RedOx electrolyte solution. The conduit is positioned in a uniform magnetic field. When a potential difference is applied across the opposing electrodes, the resulting current inte...

YOSUKE MIZUNO∗,∗∗, BING ZHANG†, BRUNO GIACOMAZZO‡, KEN-ICHI NISHIKAWA∗, PHILIP E HARDEE§, SHIGEHIRO NAGATAKI¶ and DIETER H. HARTMANN‖ ∗Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 35805, USA †Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154, USA ‡Max-Plank-Institut für Gravitationsphysik, Albert-Einstein-Instit...

The present study is a continuation of a previous one on ”hyperelliptic” axisymmetric equilibria started in [Tasso and Throumoulopoulos, Phys. Plasmas 5, 2378 (1998)]. Specifically, some equilibria with incompressible flow nonaligned with the magnetic field and restricted by appropriate side conditions like ”isothermal” magnetic surfaces, ”isodynamicity” or P +B/2 constant on magnetic surfaces ...

A general framework that incorporates the Iroshnikov-Kraichnan (IK) and Goldreich-Sridhar (GS) phenomenalogies of magnetohydrodynamic (MHD) turbulence is developed. This affords a clarification of the regimes of validity of IK and GS phenomenalogies and hence help resolve some controversies in this problem. Magnetohydrodynamic (MHD) flows that occur naturally (like astrophysical situations) and...