摘要
Lattice Boltzmann simulations of fully developed rotating turbulent flow in rectangular ducts are performed. The rectangular ducts are rotated along the spanwise direction at a constant angular speed ω. The Reynolds number Reτ=uτh/ν and rotation number Roτ=2ωh/uτ are fixed at 150 and 2.5, respectively, where uτ denotes the friction velocity and h is the half duct width. A rotating Boltzmann formulation is adopted combined with a shear-improved subgrid-scale model for large eddy simulation. In order to clarify the sidewall effect, the duct aspect ratio (AR) varies from 1 to 6 and then ∞ (channel). Code validations for a square duct (AR=1) are conducted by comparing the present results with previous direct numerical simulation data from Navier-Stokes solvers. Good agreement is found, which confirms the applicability of the rotating lattice Boltzmann model for predicting wall-bounded turbulent flows subject to rotation induced centrifugal and Coriolis forces. With increasing aspect ratio, it is further observed that there exists a critical AR=4, beyond or below which the peak of the mean velocity profile is skewed to the suction or pressure side. The same critical value of AR also appears in the anisotropic invariant map indicated by the turbulence state in the duct center. Furthermore, the Ekman layer transport is persistent temporally and spatially in all duct flows and its influence on the core region decreases with increasing AR.