论文标题
在可压缩等温湍流的直接数值模拟中磁性螺旋度的反向转移：螺旋转移
Inverse transfer of magnetic helicity in direct numerical simulations of compressible isothermal turbulence: helical transfers
论文作者
论文摘要
通过傅里叶壳向壳转移分析研究了磁场和速度场不同螺旋成分在磁螺旋度的反光谱转移中的作用。磁性螺旋性和能量转移分析均在所选的数据上，从均质等温可压缩磁性水力动力动力湍流的直接数值模拟中进行，这既要受到大规模的机械强迫和小规模的螺旋电动电动驱动。作为初始条件的流体动力湍流稳态的均方根马赫数从0.1到11。可以在磁性螺旋向较大的空间尺度的光谱传递的一般情况下进行区分：局部反向传递，非局部逆转移和局部直接转移。壳分解允许将这三个现象与明显不同的速度尺度相关联，而螺旋分解允许建立不同的螺旋成分的作用以及速度场的压缩部分在不同的传输过程中。不同螺旋贡献的位置和相对强度主要由三合会螺旋几何因子确定。
The role of the different helical components of the magnetic and velocity fields in the inverse spectral transfer of magnetic helicity is investigated through Fourier shell-to-shell transfer analysis. Both magnetic helicity and energetic transfer analysis are performed on chosen data from direct numerical simulations of homogeneous isothermal compressible magnetohydrodynamic turbulence, subject to both a large-scale mechanical forcing and a small-scale helical electromotive driving. The root mean square Mach number of the hydrodynamic turbulent steady-state taken as initial condition varies from 0.1 to about 11. Three physical phenomena can be distinguished in the general picture of the spectral transfer of magnetic helicity towards larger spatial scales: local inverse transfer, non-local inverse transfer and local direct transfer. A shell decomposition allows to associate these three phenomena with clearly distinct velocity scales while the helical decomposition allows to establish the role of the different helical components and the compressive part of the velocity field on the different transfer processes. The locality and relative strength of the different helical contributions are mainly determined by the triad helical geometric factor.
