https://scholars.lib.ntu.edu.tw/handle/123456789/80906
標題: | 以重整群分析耦合場紊流模式 | 作者: | 張建成 | 關鍵字: | 重整群分析;磁流紊流場;Alfvén效應;等效渦漩黏滯係數;磁阻係數;Renormalization group analysis;magnetohydrodynamic turbulence;Alfvén effect;effective eddy viscosity;magnetic resistivity. | 公開日期: | 31-七月-2004 | 出版社: | 臺北市:國立臺灣大學應用力學研究所 | 摘要: | 本研究旨在以重整群分析方法研究不 可壓縮之耦合磁流場紊流模式,在(1)平均 磁導相較於平均流速為可忽略及(2)Alfvén 效應成立的假設下,我們可以建立一個遞 迴重整群的程序,而建構出重整群轉換, 在此轉換下得到一具有換尺不變性的耦合 磁流場方程組,此轉換的固定點在數學上 可被等價成渦漩黏滯力在Fourier 空間中的 積微分方程組,藉由此積微分方程組的求 解,發現流場能量光譜與波數的-5/3 次方 呈正比關係。 In this study, we continue with a recursive renormalization group (RG) analysis of incompressible turbulence, aiming at investigating various turbulent properties of three-dimensional magneto- hydrodynamics (MHD). In particular, we are able to locate the fixed point (i.e. the invariant effective eddy viscosity) of the RG transformation under the following conditions. (i) The mean magnetic induction is relatively weak compared to the mean flow velocity. (ii) The Alfvén effect holds, that is, the fluctuating velocity and magnetic induction are nearly parallel and are approximately equal in magnitude. It is found under these conditions that re-normalization does not incur an increment of the magnetic resistivity, while the coupling effect tends to reduce the invariant effective eddy viscosity. Both the velocity and magnetic energy spectra are shown to follow the Kolmogorov k-5/3 in the inertial subrange; this is consistent with some laboratory measurements and observations in astronomical physics. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/21706 | 其他識別: | 922212E002045 | Rights: | 國立臺灣大學應用力學研究所 |
顯示於: | 應用力學研究所 |
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922212E002045.pdf | 70.85 kB | Adobe PDF | 檢視/開啟 |
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