Longitudinal and transverse structure functions in high Reynolds-number magneto-hydrodynamic turbulence. (16th December 2016)

• Record Type: Journal Article
• Authors: Friedrich, J; Homann, H; Schäfer, T; Grauer, R
• Is Part Of: New journal of physics. Volume 18:Number 12(2016:Dec.)
• Publication Date: 2016-12-16
• Subjects: high Reynolds-number turbulence -- magneto-hydrodynamics -- structure functions -- direct numerical simulations; 47.27.Ak -- 47.27.Jv -- 47.27.E- -- 47.27.er -- 47.27.Gs -- 52.30.Cv -- 52.35.Ra -- 52.65.Kj; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/18/12/125008
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We investigate the scaling behavior of longitudinal and transverse structure functions in homogeneous and isotropic magneto-hydrodynamic (MHD) turbulence by means of an exact hierarchy of structure function equations as well as by direct numerical simulations of two- and three-dimensional MHD turbulence. In particular, rescaling relations between longitudinal and transverse structure functions are derived and utilized in order to compare different scaling behavior in the inertial range. It is found that there are no substantial differences between longitudinal and transverse structure functions in MHD turbulence. This finding stands in contrast to the case of hydrodynamic turbulence which shows persistent differences even at high Reynolds numbers. We propose a physical picture that is based on an effective reduction of pressure contributions due to local regions of same magnitude and alignment of velocity and magnetic field fluctuations. Finally, our findings underline the importance of the pressure term for the actually observed scaling differences in hydrodynamic turbulence.