Large Eddy Simulation of Turbulent Flow and Mixing Time in a Gas-Liquid Stirred Tank
Large Eddy Simulation of Turbulent Flow and Mixing Time in a Gas-Liquid Stirred Tank
复制标题
气液搅拌槽内湍流与混合时间的大涡模拟
DOI：
10.1021/ie202447n
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发表时间：
2012-07
期刊：
影响因子：
--
通讯作者：
Mu, Junjuan
中科院分区：
文献类型：
--
作者：
Zhang, Qinghua;Yang, Chao;Mao, Zai-Sha;Mu, Junjuan
搅拌时间是影响搅拌反应器放大和设计的关键参数。虽然用计算流体力学(CFD)方法预测搅拌槽内混合时间的论文已经很多，但基于大涡模拟(LES)的气液搅拌槽内混合时间预测的报道却很少。本文提出了一种基于欧拉-欧拉模型的大涡模拟方法，用于预测Rushton涡轮搅拌气液搅拌槽内的混合时间。为了验证模拟结果，采用电导法进行了混合时间实验。在目前的大涡模拟中，使用了Smagorinsky次网格尺度模式来模拟次网格尺度对分辨率的影响。考察了进料位置、叶轮转速、气体流量等操作参数对混合时间的影响。结果表明，用大涡模拟方法预测的示踪剂浓度分布更加不规则和逼真。搅拌时间随叶轮转速的增加而缩短。但是，随着气体流量的增加，混合时间先增加后趋于平稳。用大涡模拟方法预测的混合时间与实测值吻合较好。
Mixing time is a key parameter relevant to the scale-up and design of agitated reactors. Although there have been many published papers on mixing times in stirred tanks predicted by computational fluid dynamics (CFD), there are few reports on the large eddy simulation (LES) based prediction of the mixing time in a gas liquid stirred tank. In this work, an LES method based on an Eulerian-Eulerian model is presented for predicting the mixing time in a gas liquid stirred tank agitated by a Rushton turbine. In order to verify the simulated results, mixing time experiments were carried out using a conductivity technique. In the present LES, the Smagorinsky subgrid scale model was used to model the effect of subgrid scale on the resolved scales. The concentration distributions and operating parameters such as feed positions, impeller speeds, and gas flow rates on the mixing time were examined. It is shown that the predicted concentration distributions of tracers are more irregular and realistic by using LES. Also, the mixing time decreases with the increase of impeller speed. However, with increasing gas flow rate, the mixing time first increases and then levels off. The predicted mixing time by the LES method shows good agreement with the measured values.
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影响因子：
3.8
作者：
Yanhong Zhang;Chao Yang;Z. Mao
通讯作者：
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影响因子：
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作者：
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DOI：
10.1016/s0255-2701(00)00128-8
发表时间：
2001-03-01
影响因子：
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作者：
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作者：
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影响因子：
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作者：
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