Iyer Kartik P, Mazzitelli Irene, Bonaccorso Fabio, Pouquet Annick, Biferale Luca
University of Rome and INFN, 00133, Tor Vergata Rome, Italy.
Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, 80303, Boulder, CO, USA.
Eur Phys J E Soft Matter. 2015 Dec;38(12):128. doi: 10.1140/epje/i2015-15128-x. Epub 2015 Dec 7.
The effects of changing the orientation of the rotation axis on homogeneous turbulence is considered. We perform direct numerical simulations on a periodic box of 1024(3) grid points, where the orientation of the rotation axis is changed (a) at a fixed time instant (b) regularly at time intervals commensurate with the rotation time scale. The former is characterized by a dominant inverse energy cascade whereas in the latter, the inverse cascade is stymied due to the recurrent changes in the rotation axis resulting in a strong forward energy transfer and large-scale structures that resemble those of isotropic turbulence.
考虑了改变旋转轴方向对均匀湍流的影响。我们在一个具有1024(3)个网格点的周期性盒子上进行直接数值模拟，其中旋转轴的方向在以下两种情况下发生改变：(a) 在固定时刻；(b) 以与旋转时间尺度相称的时间间隔定期改变。前者的特征是存在主导的反向能量串级，而在后者中，由于旋转轴的反复变化，反向能量串级受到阻碍，导致强烈的正向能量传递以及类似于各向同性湍流的大尺度结构。
