http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Relativistic Force-Free MHD Turbulence in a Black Hole's Magnetosphere
Jungyeon Cho 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.4
In a black hole's magnetosphere, the magnetic energy density can be larger than that of matter. In the extremely strong magnetic .eld limit, the Alfven speed approaches the speed of light, and the inertia of charge carriers can be neglected. We discuss magnetohydrodynamic (MHD) turbulence in this limit. The MHD turbulence in this limit shows the following scaling relations: First, the energy spectrum is consistent with a Kolmogorov spectrum: E(k) ≫ k¡5=3. Second, the turbulence shows a Goldreich-Sridhar type anisotropy: kk / k2=3 ? , where kk and k? are wavenumbers along and perpendicular to the local mean magnetic .eld directions, respectively. These scalings are in agreement with earlier theoretical predictions by Thompson & Blaes.aD
Simulations on Incompressible MHD Turbulence
CHO JUNGYEON The Korean Astronomical Society 2001 Journal of The Korean Astronomical Society Vol.34 No.4
The study of incompressible magnetohydrodynamic (MHD) turbulence gives useful insights on many astrophysical problems. We describe a pseudo-spectral MHD code suitable for the study of incompressible turbulence. We review our recent' works on direct three-dimensional numerical simulations for MHD turbulence in a periodic box. In those works, we use a pseudo-spectral code to solve the incompressible MHD equations. We first discuss the structure and properties of turbulence as functions of scale. The results are consistent with the scaling law recently proposed by Goldreich & Sridhar. The scaling law is based on the concept of scale-dependent isotropy: smaller eddies are more elongated than larger ones along magnetic field lines. This scaling law substantially changes our views on MHD turbulence. For example, as noted by Lazarian & Vishniac, the scaling law can provide a fast reconnection rate. We further discuss how the study of incompressible MHD turbulence can help us to understand physical processes in interstellar medium (ISM) by considering imbalanced cascade and viscous damped turbulence.