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 Metzuer constant k5. 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 k5. Method Ⅲ showed both good accuracy and ease of use.
用多重参考框架(MRF ) impeller 方法，一条双螺旋状的带子(DHR ) 产生的三维的非牛顿的流动地 impeller 被模仿了。数字模拟计算的速度地类似于以前的研究，力量常数与试验性的数据同意了很好。三计算液体动态(CFD ) 方法，标记我， II 和 III，被用来计算 Metzner 经常的 ks。结果证明从 slop 方法的计算价值(方法我) 与试验性的数据一致。方法 II，它拿了最大的圆周一般水准砍在是的 impeller 附近的率有效砍计算 ks 的率，对实验的也显示出的好同意。然而，两个方法受不了计算过程的复杂性。一个新方法(方法 III ) 在这份报纸被设计为精明的 ks 在 impeller 附近把区域加权的平均粘性用作有效粘性。方法 III 显示出好精确性和容易使用。
基金
Supported by the Natural Science Foundation of Tianjin （07JCZDJC02600）.
