SCI和EI收录∣中国化工学会会刊

Chin.J.Chem.Eng. ›› 2008, Vol. 16 ›› Issue (5): 686-692.

• TRANSPORT PHENOMENA & FLUID MECHANICS • Previous Articles     Next Articles

Calculation of Metzner Constant for Double Helical Ribbon Impeller by Computational Fluid Dynamic Method

ZHANG Minge1, ZHANG Lühong1, JIANG Bin1,2, YIN Yuguo1, LI Xingang1,2   

  1. 1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China;
    2. National Engineering Research Centre of Distillation Technology, Tianjin 300072, China
  • Received:2007-11-11 Revised:2008-07-10 Online:2008-10-28 Published:2008-10-28
  • Supported by:

    the Natural Science Foundation of Tianjin(07JCZDJC02600).

Calculation of Metzner Constant for Double Helical Ribbon Impeller by Computational Fluid Dynamic Method

张敏革1, 张吕鸿1, 姜斌1,2, 尹玉国1, 李鑫钢1,2   

  1. 1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China;
    2. National Engineering Research Centre of Distillation Technology, Tianjin 300072, China
  • 通讯作者: ZHANG Lühong,E-mail:zhanglvh@tju.edu.cn
  • 基金资助:

    the Natural Science Foundation of Tianjin(07JCZDJC02600).

Abstract: Using the multiple reference frames(MRF)impeller method,the three-dimensional non-Newtonian flow field generated by a double helical ribbon(DHR)impeller has been simulated.The velocity field calculated by the numerical simulation was similar to the previous studies and the power constant agreed well with the experimental data.Three computational fluid dynamic(CFD)methods,labeled I,Ⅱ and Ⅲ,were used to compute the Metzner constant ks.The results showed that the calculated value from the slop method(method I)was consistent with the experimental data.Method II,which took the maximal circumference-average shear rate around the impeller as the effective shear rate to compute ks,also showed good agreement with the experiment.However,both methods suffer from the complexity of calculation procedures.A new method(method Ⅲ)was devised in this paper to use the area-weighted average viscosity around the impeller as the effective viscosity for calculating ks.Method Ⅲshowed both good accuracy and ease of use.

Key words: computational fluid dynamic, double helical ribbon impeller, non-Newtonian fluid, Metzner constant

摘要: Using the multiple reference frames(MRF)impeller method,the three-dimensional non-Newtonian flow field generated by a double helical ribbon(DHR)impeller has been simulated.The velocity field calculated by the numerical simulation was similar to the previous studies and the power constant agreed well with the experimental data.Three computational fluid dynamic(CFD)methods,labeled I,Ⅱ and Ⅲ,were used to compute the Metzner constant ks.The results showed that the calculated value from the slop method(method I)was consistent with the experimental data.Method II,which took the maximal circumference-average shear rate around the impeller as the effective shear rate to compute ks,also showed good agreement with the experiment.However,both methods suffer from the complexity of calculation procedures.A new method(method Ⅲ)was devised in this paper to use the area-weighted average viscosity around the impeller as the effective viscosity for calculating ks.Method Ⅲshowed both good accuracy and ease of use.

关键词: computational fluid dynamic, double helical ribbon impeller, non-Newtonian fluid, Metzner constant