Rädler Karl-Heinz, Stepanov Rodion
Astrophysical Institute Potsdam, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 May;73(5 Pt 2):056311. doi: 10.1103/PhysRevE.73.056311. Epub 2006 May 24.
The mean electromotive force caused by turbulence of an electrically conducting fluid, which plays a central part in mean-field electrodynamics, is calculated for a rotating fluid. Going beyond most of the investigations on this topic, an additional mean motion in the rotating frame is taken into account. One motivation for our investigation originates from a planned laboratory experiment with a Ponomarenko-type dynamo. In view of this application the second-order correlation approximation is used. The investigation is of high interest in astrophysical context, too. Some contributions to the mean electromotive are revealed which have not been considered so far, in particular contributions to the effect and related effects due to the gradient of the mean velocity. Their relevance for dynamo processes is discussed. In a forthcoming paper the results reported here will be specified to the situation in the laboratory and partially compared with experimental findings.
在平均场电动力学中起核心作用的、由导电流体湍流引起的平均电动势，针对旋转流体进行了计算。超越了关于该主题的大多数研究，考虑了旋转参考系中的附加平均运动。我们进行这项研究的一个动机源自一项计划中的关于Ponomarenko型发电机的实验室实验。鉴于此应用，采用了二阶相关近似。该研究在天体物理学背景下也具有很高的研究价值。揭示了一些迄今为止尚未被考虑的对平均电动势的贡献，特别是由于平均速度梯度对该效应及相关效应的贡献。讨论了它们与发电机过程的相关性。在即将发表的一篇论文中，这里报告的结果将针对实验室情况进行细化，并部分与实验结果进行比较。
