欢迎访问过程工程学报, 今天是

›› 2014, Vol. 14 ›› Issue (1): 23-29.

• 流动与传递 • 上一篇    下一篇

最大叶片式桨流体动力学性能的数值模拟

李健达 苏红军 张庆 徐世艾   

  1. 烟台大学化工学院 烟台大学化工学院 烟台大学化工学院 烟台大学化工学院
  • 收稿日期:2013-11-05 修回日期:2013-12-24 出版日期:2014-02-20 发布日期:2014-02-20
  • 通讯作者: 李健达

Numerical Simulation on Hydrodynamic Performance of the Maxblend Impeller

LI Jian-da SU Hong-jun ZHANG Qing XU Shi-ai   

  1. Chemicals Manufacture Engineering Key Lab of Shandong Universities, Shandong Provincial Key Lab of Chemical Engineering and Process Chemicals Manufacture Engineering Key Lab of Shandong Universities, Shandong Provincial Key Lab of Chemical Engineering and Process Chemicals Manufacture Engineering Key Lab of Shandong Universities, Shandong Provincial Key Lab of Chemical Engineering and Process Chemicals Manufacture Engineering Key Lab of Shandong Universities, Shandong Provincial Key Lab of Chemical Engineering and Process
  • Received:2013-11-05 Revised:2013-12-24 Online:2014-02-20 Published:2014-02-20
  • Contact: LI Jian-da

PDF

摘要： 运用CFD方法研究了最大叶片式桨在层流区域内的流体动力学性能，模拟体系为高粘度牛顿流体和非牛顿流体，主要考察桨叶的功耗特性、Metzner常数、剪切性能和排液性能. 结果表明，功耗计算值与文献实验值基本一致；桨叶的Metzner常数ks=10与流变行为指数n无关；搅拌形成双循环流型，釜中部桨叶所在区剪切速率大、排液量大，产生的漩涡流也大，导致剪切效率低于0.5；随雷诺数增加(Ren=1.4, 5.0, 7.6)，全釜平均剪切速率(3.40, 9.91, 15.05 s-1)和全釜平均排液量(0.0014, 0.0033, 0.0052 m3/s)逐渐增加，尤其是桨叶下端两翼区平均剪切速率(4.36, 11.48, 16.35 s-1)和平均排液量(0.0026, 0.0064, 0.0095 m3/s)增加相对较大. 说明Ren增加，搅拌混合作用加强，剪切速率大产生的界面积大，排液量大使高低剪切区内流体快速循环，有利于流体高效混合.

关键词: 最大叶片式桨, 牛顿流体, 非牛顿流体, 功耗, 流体混合

Abstract: The hydrodynamic characterization of Maxblend impeller in the laminar regimes is studied by CFD simulation in the systems of viscous Newtonian and non-Newtonian pseudoplastic fluids. The power consumption, Metzner constant (ks), shear performance and axial pumping are examined. The results indicate that the power curve is consistent with the experimental data. ks=10 remains almost constant for a wide range of rheological behavior indices. The Maxblend impeller presents a flow pattern structure of double circulation. The region of impeller has high shear rate and large discharge quantity. And large vortex flow is generated, which results in the shear efficiency lower than 0.5. As the Reynolds number increases (Ren=1.4, 5.0, 7.6), the average shear rate (3.40, 9.91, 15.05 s-1) and pumping (0.0014, 0.0033, 0.0052 m3/s) of the tank increase, especially in the wing area at the bottom of impeller, the increase of average shear rate (3.40, 9.91, 15.05 s-1) and pumping (0.0014, 0.0033, 0.0052 m3/s) is relatively large. The mixing effect is strengthened and large junction area generated by high shear rate. Rapid cycling is induced by strong pumping between high and low areas of shear rate, and the fluid reaches high mixing efficiency as a result.

Key words: Maxblend impeller, Newtonian fluid, non-Newtonian fluid, power consumption, fluid mixing

中图分类号: