On the Conductivity of a Magnetoactive Turbulent Plasma

基于磁活性 GES 的太阳等离子体湍流不稳定性的理论分析

A theoretic analysis of magnetoactive GES-based turbulent solar plasma instability

本文应用引力-静电鞘（GES）模型研究双流体太阳等离子体的磁活性日震振荡，通过数值平台揭示了不同参数下波动的色散特征及稳定性变化规律。

Electrodynamics of turbulent fluids with fluctuating electric conductivity

The influence of fluctuating conductivity on the coefficients known from the mean-field electrodynamics is considered. If the conductivity fluctuations are assumed as uncorrelated with the turbulent velocity field then only the effective magnetic diffusivity of the fluid is reduced and the decay time of a large-scale magnetic field is increased. If the fluctuations of conductivity and flow are correlated in a certain direction then an additional diamagnetic pumping effect results transporting magnetic field in opposite direction to the resistivity flux vector $\langle η'\vec{u}'\rangle$. Even …

Conductivity spectrum and dispersion relation in solar wind turbulence

Magnetic turbulence in the solar wind is treated from the point of view of electrodynamics. This can be done based on the use of Poynting's theorem attributing all turbulent dynamics to the spectrum of turbulent conductivity. For two directions of propagation of the turbulent fluctuations of the electromagnetic field with respect to the mean plus external magnetic fields an expression is constructed for the spectrum of turbulent dissipation. Use of solar wind observations of electromagnetic power spectral densities in the inertial subrange then allows determination of the conductivity spectrum…

Magnetic Reconnection in Turbulent Diluted Plasmas

We study magnetic reconnection events in a turbulent plasma within the two-fluid theory. By identifying the diffusive regions, we measure the reconnection rates as function of the conductivity and current sheet thickness. We have found that the reconnection rate scales as the squared of the inverse of the current sheet's thickness and is independent of the aspect ratio of the diffusive region, in contrast to other analytical, e.g. the Sweet-Parker and Petscheck, and numerical models. Furthermore, while the reconnection rates are also proportional to the square inverse of the conductivity, the …

Poynting's theorem in magnetic turbulence

Poynting's theorem is used to obtain an expression for the turbulent power-spectral density as function of frequency and wavenumber in low-frequency magnetic turbulence. No reference is made to Elsasser variables as is usually done in magnetohydrodynamic turbulence mixing mechanical and electromagnetic turbulence. We rather stay with an implicit form of the mechanical part of turbulence as suggested by electromagnetic theory in arbitrary media. All of mechanics and flows is included into a turbulent response function which by appropriate observations can be determined from knowledge of the tur…

洛伦兹力对湍流发电机转变的调节作用

Lorentz force mediation of turbulent dynamo transitions

本研究通过改变磁普朗特数调节洛伦兹力，发现其强度决定恒星对流发电机转变，包括较差自转模式切换，并受局部磁罗斯比数控制。