Transfer of energy to two-dimensional large scales in forced, rotating three-dimensional turbulence
Transfer of energy to two-dimensional large scales in forced, rotating three-dimensional turbulence
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DOI：
10.1063/1.870022
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发表时间：
1999-05
影响因子：
4.6
通讯作者：
L. Smith;F. Waleffe
中科院分区：
文献类型：
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作者：
L. Smith;F. Waleffe
采用三周期箱的数值模拟方法研究了旋转框架内的强迫湍流。随机强迫是三维的，局部化在一个中间波数kf左右。结果表明，当转速足够大时，能量传递到比强迫尺度更大的尺度上。当k<kf时，能谱的标度趋于E(k)∝k−3。k<kf的几乎所有能量都存在于垂直于旋转z轴的二维平面上，因此大尺度运动是准二维的，E(k)≈E(kh,kz=0)，其中kh和kz分别是波矢量的水平分量和垂直分量。大尺度由气旋涡旋组成。讨论了造成二维化的可能机制。二维谱E(kh,kz=0)∝kh−3的发展类似于β平面湍流动力学导致的莱茵谱E(ky,kx=0)∝ky−5。
Forced turbulence in a rotating frame is studied using numerical simulations in a triply periodic box. The random forcing is three dimensional and localized about an intermediate wavenumber kf. The results show that energy is transferred to scales larger than the forcing scale when the rotation rate is large enough. The scaling of the energy spectrum approaches E(k)∝k−3 for k<kf. Almost all of the energy for k<kf lies in the two-dimensional (2D) plane perpendicular to the rotation z-axis, and thus the large-scale motions are quasi-2D with E(k)≈E(kh,kz=0), where kh and kz are, respectively, the horizontal and vertical components of the wavevector. The large scales consist of cyclonic vortices. Possible mechanisms responsible for the two-dimensionalization are discussed. The development of the 2D spectrum E(kh,kz=0)∝kh−3 is analogous to the dynamics of β-plane turbulence leading to the Rhines spectrum E(ky,kx=0)∝ky−5.