Large-eddy simulation for decaying magnetohydrodynamic turbulence at low magnetic Reynolds number
文献类型：期刊论文
| 作者 | Fan, YuChang3; Chen, Long1,2; Ni MJ(倪明玖)1,2,3 |
| 刊名 | JOURNAL OF FLUID MECHANICS
 |
| 出版日期 | 2025-06-05 |
| 卷号 | 1012页码:28 |
| 关键词 | MHD turbulence |
| ISSN号 | 0022-1120 |
| DOI | 10.1017/jfm.2025.10184 |
| 通讯作者 | Ni, Ming-Jiu(mjni@ucas.ac.cn) |
| 英文摘要 | Large-eddy simulations have been conducted to investigate the decay law of homogeneous turbulence influenced by a magnetic field within a cubic domain, employing periodic boundary conditions. The initial integral Reynolds number is approximately 1000, while the initial interaction number $N$ ranges from 0.1-100. The results reveal that the Joule cone angle $\theta$ , half of the Joule cone, decays as $\cos \theta \sim t<^>{-1/2}$ when $N \gg 1$ . In the nonlinear stage, small-scale vortices gradually recover and restore three-dimensionality. Moreover, the corresponding critical state at small scales, marking the transition from quasi-two-dimensional structure to the onset of three-dimensionality, has been quantitatively defined. During the linear stage, based on the true magnetic damping number ( $\tau _t = \rho / (\sigma {\boldsymbol{B}}<^>2 \cos <^>2 \psi )$ , where $\sigma$ , $\boldsymbol{B}$ and $\psi$ denote the electrical conductivity, magnetic field and the angle between the wavevector and $\boldsymbol{B}$ in Fourier space, respectively), Moffatt's decay law, $K \sim t<^>{-1/2}$ , manifests at distinct times and zones in the Fourier space, with $K$ signifying turbulent kinetic energy. In the nonlinear stage, for $N \gg 1$ , a $-3$ slope in the energy power spectrum is prominently observed over an extended period. The near-equivalence of the characteristic time scales of inertial and Lorentz forces in the inertial subrange suggests a quasiequilibrium state between energy transfer and Joule dissipation in Fourier space, thereby corroborating the hypothesis proposed by Alemany et al. 1979 Journal de Mecanique 18(2): 277-313. Additionally, it is observed that pressure mediates energy transfer from horizontal kinetic energy ( $K_{\parallel }$ ) to vertical kinetic energy ( $K_{\bot }$ ), accelerating the decay of $K_{\parallel }$ . Notably, concurrent inverse and direct energy transfers emerge during the decay process. Our analysis reveals that the ratio $R$ of the maximum inverse to maximum direct energy flux correlates with the dimensionality of the turbulence, following the scaling law $R\sim (\cos \theta )<^>{-2.2}$ . |
| 分类号 | 一类/力学重要期刊 |
| WOS关键词 | MHD TURBULENCE ; ENERGY-TRANSFER ; NUMERICAL-SIMULATION ; DUCT FLOW ; SCALE ; VORTEX |
| 资助项目 | CAS[YSBR-087] ; CAS[XDB0790103] |
| WOS研究方向 | Mechanics ; Physics |
| 语种 | 英语 |
| WOS记录号 | WOS:001502320700001 |
| 资助机构 | CAS |
| 其他责任者 | Ni, Ming-Jiu |
| 源URL | [http://dspace.imech.ac.cn/handle/311007/101754]  |
| 专题 | 力学研究所_非线性力学国家重点实验室 |
| 作者单位 | 1.Chinese Acad Sci, State Key Lab Nonlinear Mech, Beijing 101408, Peoples R China 2.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 101408, Peoples R China; 3.Xi An Jiao Tong Univ, Sch Aerosp, State Key Lab Strength & Vibrat Mech Struct, Xian 710049, Shannxi, Peoples R China; |
| 推荐引用方式 GB/T 7714 | Fan, YuChang,Chen, Long,Ni MJ. Large-eddy simulation for decaying magnetohydrodynamic turbulence at low magnetic Reynolds number[J]. JOURNAL OF FLUID MECHANICS,2025,1012:28. |
| APA | Fan, YuChang,Chen, Long,&倪明玖.(2025).Large-eddy simulation for decaying magnetohydrodynamic turbulence at low magnetic Reynolds number.JOURNAL OF FLUID MECHANICS,1012,28. |
| MLA | Fan, YuChang,et al."Large-eddy simulation for decaying magnetohydrodynamic turbulence at low magnetic Reynolds number".JOURNAL OF FLUID MECHANICS 1012(2025):28. |
入库方式： OAI收割
来源：力学研究所
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