Field theoretic calculation of energy cascade rates in non-helical magnetohydrodynamic turbulence

Pramana

Mahendra K Verma1¹ 

[1] Department of Physics, Indian Institute of Technology, Kanpur 208 016, India$$

关键词: Magnetohydrodynamics;    turbulence;    field theory.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

Energy cascade rates and Kolmogorov’s constant for non-helical steady magnetohydrodynamic turbulence have been calculated by solving the flux equations to the first order in perturbation. For zero cross helicity and space dimension 𝑑 = 3, magnetic energy cascades from large length-scales to small length-scales (forward cascade). In addition, there are energy fluxes from large-scale magnetic field to small-scale velocity field, large-scale velocity field to small-scale magnetic field, and large-scale velocity field to large-scale magnetic field. Kolmogorov’s constant for magnetohydrodynamics is approximately equal to that for fluid turbulence (≈ 1.6) for Alfvén ratio 0.5 ≤ 𝑟A ≤ ∞. For higher space-dimensions, the energy fluxes are qualitatively similar, and Kolmogorov’s constant varies as 𝑑1/3. For the normalized cross helicity 𝜎c → 1, the cascade rates are proportional to (1-𝜎c)/(1+𝜎c), and the Kolmogorov’s constants vary significantly with 𝜎c.

【 授权许可】

Unknown