We investigates the effect of Taylor-Grtler vortex on the Reynolds stress transport in the rotating turbulent channel flow by direct numerical simulation. The Taylor-Grtler vortex is detected by longitudinal avera...We investigates the effect of Taylor-Grtler vortex on the Reynolds stress transport in the rotating turbulent channel flow by direct numerical simulation. The Taylor-Grtler vortex is detected by longitudinal average of velocity fluctuation in the channel and defined as TG fluctuation. It has been found that turbulent diffusion is significant in the Reynolds stress transportation at the suction side of rotating turbulent channel in contrast with the turbulent channel flow without rotation and Taylor-Grtler vortex plays an important role in the turbulent diffusion in Reynolds stress transport. The paper focuses on the low and moderate rotation number, but the effect of the rotation number on the Reynolds stress transport is also reported.展开更多
The supercritical flow states of the spherical Couette flow between two concentric spheres with the inner sphere rotating are investigated via direct numerical simulation using a three-dimensional finite difference me...The supercritical flow states of the spherical Couette flow between two concentric spheres with the inner sphere rotating are investigated via direct numerical simulation using a three-dimensional finite difference method.For comparison with experiments of Nakabayashi et al.And Wimmer,a narrow gap and a medium gap with clearance ratioβ=0.06 and 0.18 respectively areconsidered for the Reynolds number range covering the first Hopfbifurcation point.With adequate initial conditions and temporaryimposition of small wave-type perturbation,multiple periodicflow states with three different pair numbers of spiralTaylor-Gortler(TG)vortices have been simulated successfullyforβ=0.06,of which the 1-pair and 2-pair of spiral Tgvortices are newly obtained.Three different periodic flow stateswith shear waves,Stuart vortices or wavy outflow boundary,have been obtained forβ=0.18.Analysis of the numerical resultsreveals these higher flow modes in terms of fundamental frequency,wave number and spatial structure.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 10872109, 10828204 and 10925210)the sponsor from the Sino-French Laboratory LIAMA (97-03)
文摘We investigates the effect of Taylor-Grtler vortex on the Reynolds stress transport in the rotating turbulent channel flow by direct numerical simulation. The Taylor-Grtler vortex is detected by longitudinal average of velocity fluctuation in the channel and defined as TG fluctuation. It has been found that turbulent diffusion is significant in the Reynolds stress transportation at the suction side of rotating turbulent channel in contrast with the turbulent channel flow without rotation and Taylor-Grtler vortex plays an important role in the turbulent diffusion in Reynolds stress transport. The paper focuses on the low and moderate rotation number, but the effect of the rotation number on the Reynolds stress transport is also reported.
基金This work was supported by the State Key Basic Research Program(Grant No.G1999032801)the National Natural Science Foundation of China(Grant No.10172089).
文摘The supercritical flow states of the spherical Couette flow between two concentric spheres with the inner sphere rotating are investigated via direct numerical simulation using a three-dimensional finite difference method.For comparison with experiments of Nakabayashi et al.And Wimmer,a narrow gap and a medium gap with clearance ratioβ=0.06 and 0.18 respectively areconsidered for the Reynolds number range covering the first Hopfbifurcation point.With adequate initial conditions and temporaryimposition of small wave-type perturbation,multiple periodicflow states with three different pair numbers of spiralTaylor-Gortler(TG)vortices have been simulated successfullyforβ=0.06,of which the 1-pair and 2-pair of spiral Tgvortices are newly obtained.Three different periodic flow stateswith shear waves,Stuart vortices or wavy outflow boundary,have been obtained forβ=0.18.Analysis of the numerical resultsreveals these higher flow modes in terms of fundamental frequency,wave number and spatial structure.
