Kleeorin Nathan, Rogachevskii Igor
Department of Mechanical Engineering, Ben-Gurion University of the Negev, P. O. Box 653, Beer-Sheva 84105, Israel.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Apr;73(4 Pt 2):046303. doi: 10.1103/PhysRevE.73.046303. Epub 2006 Apr 5.
We studied the effect of the turbulent heat flux on the Reynolds stresses in a rotating turbulent convection. To this end we solved a coupled system of dynamical equations which includes the equations for the Reynolds stresses, the entropy fluctuations, and the turbulent heat flux. We used a spectral tau approximation in order to close the system of dynamical equations. We found that the ratio of the contributions to the Reynolds stresses caused by the turbulent heat flux and the anisotropic eddy viscosity is of the order of approximately 10(L rho/l0)2, where l0 is the maximum scale of turbulent motions and L rho is the fluid density variation scale. This effect is crucial for the formation of the differential rotation and should be taken into account in the theories of the differential rotation of the Sun, stars, and planets. In particular, we demonstrated that this effect may cause the differential rotation which is comparable with the typical solar differential rotation.
我们研究了旋转湍流对流中湍流通量对雷诺应力的影响。为此，我们求解了一个动力学方程组，该方程组包括雷诺应力、熵涨落和湍流通量的方程。我们使用谱τ近似来封闭动力学方程组。我们发现，由湍流通量和各向异性涡粘性对雷诺应力的贡献之比约为10(Lρ/l0)²，其中l0是湍流运动的最大尺度，Lρ是流体密度变化尺度。这种效应对于较差自转的形成至关重要，在太阳、恒星和行星的较差自转理论中应予以考虑。特别是，我们证明了这种效应可能导致与典型太阳较差自转相当的较差自转。
