Numerical study of turbulent magnetohydrodynamic channel flow
Numerical study of turbulent magnetohydrodynamic channel flow
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DOI：
10.1017/s0022112006003673
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发表时间：
2007-01
影响因子：
3.7
通讯作者：
By Thomas Boeck;D. Krasnov;E. Zienicke
中科院分区：
文献类型：
--
作者：
By Thomas Boeck;D. Krasnov;E. Zienicke
采用高分辨率直接数值模拟方法研究了具有电绝缘壁的磁流体动力学槽道湍流的平均流动特性。在准静态近似下计算了均匀壁面法向磁场所产生的洛伦兹力。对于强磁场，平均速度分布显示出一个明确的三层结构，包括一个粘性区域附近的每个壁和一个高原在中间连接对数层。这种结构反映了粘性，湍流和电磁应力的意义，在流向的动量平衡主导的粘性，对数和高原地区，分别。对数层的宽度随雷诺数和哈特曼数的比值而变化。湍流应力通常比混合长度模型预测的更快地远离壁衰减。
Mean flow properties of turbulent magnetohydrodynamic channel flow with electrically insulating channel walls are studied using high-resolution direct numerical simulations. The Lorentz force due to the homogeneous wall-normal magnetic field is computed in the quasi-static approximation. For strong magnetic fields, the mean velocity profile shows a clear three-layer structure consisting of a viscous region near each wall and a plateau in the middle connected by logarithmic layers. This structure reflects the significance of viscous, turbulent, and electromagnetic stresses in the streamwise momentum balance dominating the viscous, logarithmic, and plateau regions, respectively. The width of the logarithmic layers changes with the ratio of Reynolds- and Hartmann numbers. Turbulent stresses typically decay more rapidly away from the walls than predicted by mixing-length models.