Transitional Flow in a Rushton Turbine Stirred Tank
Transitional Flow in a Rushton Turbine Stirred Tank
复制标题
Rushton 涡轮搅拌槽中的过渡流
DOI：
10.1002/aic.15809
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Derksen J. J.
中科院分区：
文献类型：
--
作者：
Zhang Yulong;Gao Zhengming;Li Zhipeng;Derksen J. J.
在Rushton涡轮搅拌槽中，牛顿液体在叶轮附近的单相流动经历层流-湍流过渡的方式已经通过实验（用粒子图像测速）和计算进行了详细的研究。当雷诺数等于或大于6000时，平均速度和速度波动水平与叶顶转速成正比，即表现出与雷诺数无关的特性。令人惊讶的流动结构被测量出来——并通过独立的重复实验得到证实——雷诺数在1300左右。当雷诺数从完全紊流状态降低后，叶轮后尾涡系统减弱，且上涡减弱的程度远大于下涡。用各种方法（直接数值模拟、过渡湍流建模）和软件实现（ANSYS‐Fluent商业软件、lattice‐Boltzmann内部软件）进行的模拟仅部分成功地代表了实验观察到的层流-湍流过渡。©2017美国化学工程学会化工学报，63:3610-3623,2017
The way in which the single phase flow of Newtonian liquids in the vicinity of the impeller in a Rushton turbine stirred tank goes through a laminar‐turbulent transition has been studied in detail experimentally (with Particle Image Velocimetry) as well as computationally. For Reynolds numbers equal to or higher than 6000, the average velocities and velocity fluctuation levels scale well with the impeller tip speed, that is, show Reynolds independent behavior. Surprising flow structures were measured—and confirmed through independent experimental repetitions—at Reynolds numbers around 1300. Upon reducing the Reynolds number from values in the fully turbulent regime, the trailing vortex system behind the impeller blades weakens with the upper vortex weakening much stronger than the lower vortex. Simulations with a variety of methods (direct numerical simulations, transitional turbulence modeling) and software implementations (ANSYS‐Fluent commercial software, lattice‐Boltzmann in‐house software) have only partial success in representing the experimentally observed laminar‐turbulent transition. © 2017 American Institute of Chemical EngineersAIChE J, 63: 3610–3623, 2017