Chaotic mixing performance in rigid-flexible impeller stirred tank with eccentric air jet

被引：0
|
作者：
Qiu F. [1 ]
Liu Z. [1 ]
Liu R. [1 ]
Quan X. [1 ,3 ]
Chen J. [1 ]
Gu D. [1 ]
Li B. [1 ]
Wang Y. [2 ]
机构：
[1] School of Chemistry and Chemical Engineering, Chongqing University, Chongqing
[2] State Key Laboratory of Chemical Engineering, Tsinghua University, Beijing
[3] College of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing
来源：
Huagong Xuebao/CIESC Journal | 2018年 / 69卷 / 02期
基金：
中国国家自然科学基金;
关键词：
Chaos; Eccentric air jet; Largest Lyapunov exponent; Multi-scale entropy; Rigid-flexible impeller;
D O I：
10.11949/j.issn.0438-1157.20171041
中图分类号：
学科分类号：
摘要：
Isolated mixing regions exist widely in the stirred tank, which is a major obstacle for efficient mixing. In order to increase the mixing efficiency, the method of multiple flow fields coupling, which can bring out fluid chaos, is used to increase fluid mixing efficiency by reducing the isolated mixing regions. The largest Lyapunov exponent and multi-scale entropy are investigated with the aid of Matlab in the coupling of eccentric air jet and rigid-flexible combined impeller system. Meanwhile, the effects of impeller types, impeller off-bottom clearances, air jet flow rates, and the impeller speeds on the mixing performance are analyzed at different eccentricities. The results show that the flow field coupling of the rigid-soft-flow of multi-body motion of rigid-flexible combined impeller and eccentric air jet destroy the symmetry flow in the process of fluid mixing and made more fluid into the chaotic state. The LLE of rigid-flexible combined impeller is larger than that of rigid impeller. The LLE of rigid-flexible combined impeller compared with the other three types agitators (IRDT, RDT, RF-IRDT) increases 42.8%, 27.0%, and 6.9%. When the eccentricity of the air jet is equal to 0.6, the maximum LLE value is 6.5%, 2.4%, 17.6% and 25.1% which is higher than the other eccentricity (0.8, 0.4, 0.2, 0). The results of this study can provide the theoretical basis for the optimal design of rigid-flexible agitator. © All Right Reserved.
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页码：618 / 624
页数：6
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