Buzzicotti Michele, Clark Di Leoni Patricio, Biferale Luca
Department of Physics & INFN, University of Rome "Tor Vergata", Via della Ricerca Scientifica 1, 00133, Rome, Italy.
Eur Phys J E Soft Matter. 2018 Nov 12;41(11):131. doi: 10.1140/epje/i2018-11742-4.
Rotating turbulence is an example of a three-dimensional system in which an inverse cascade of energy, from the small to the large scales, can be formed. While usually understood as a byproduct of the typical bidimensionalization of rotating flows, the role of the three-dimensional modes is not completely comprehended yet. In order to shed light on this issue, we performed direct numerical simulations of rotating turbulence where the 2D modes falling in the plane perpendicular to rotation are removed from the dynamical evolution. Our results show that while the two-dimensional modes are key to the formation of a stationary inverse cascade, the three-dimensional degrees of freedom play a non-trivial role in bringing energy to the larger scales also. Furthermore, we show that this backwards transfer of energy is carried out by the homochiral channels of the three-dimensional modes.
旋转湍流是一个三维系统的例子，在该系统中可以形成从小尺度到大尺度的能量反向级联。虽然通常被理解为旋转流典型二维化的副产品，但三维模式的作用尚未被完全理解。为了阐明这个问题，我们对旋转湍流进行了直接数值模拟，在动力学演化中去除了垂直于旋转平面的二维模式。我们的结果表明，虽然二维模式是形成稳定反向级联的关键，但三维自由度在将能量传递到更大尺度方面也起着重要作用。此外，我们表明这种能量的反向传递是由三维模式的同手性通道进行的。
