Mininni Pablo D, Montgomery David C
National Center for Atmospheric Research, P.O. Box 3000, Boulder, Colorado 80307, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Nov;72(5 Pt 2):056320. doi: 10.1103/PhysRevE.72.056320. Epub 2005 Nov 18.
We present direct numerical simulations of dynamo action in a forced Roberts flow. The behavior of the dynamo is followed as the mechanical Reynolds number is increased, starting from the laminar case until a turbulent regime is reached. The critical magnetic Reynolds for dynamo action is found, and in the turbulent flow it is observed to be nearly independent on the magnetic Prandtl number in the range from approximately 0.3 to approximately 0.1. Also the dependence of this threshold with the amount of mechanical helicity in the flow is studied. For the different regimes found, the configuration of the magnetic and velocity fields in the saturated steady state are discussed.
我们展示了在强迫罗伯茨流中发电机作用的直接数值模拟。随着机械雷诺数的增加，从层流情况开始直至达到湍流状态，跟踪发电机的行为。找到了发电机作用的临界磁雷诺数，并且在湍流中观察到它在大约0.3到大约0.1的范围内几乎与磁普朗特数无关。还研究了该阈值与流中机械螺旋度的量之间的依赖性。对于所发现的不同状态，讨论了饱和稳态下磁场和速度场的配置。
