摘要
采用计算流体力学方法对双螺带-螺杆搅拌桨在层流域内的搅拌流场进行了数值模拟,考察流体为高黏牛顿流体和假塑性非牛顿流体.数值模拟计算得到的功率值与实验测量值吻合较好;双螺带-螺杆搅拌桨的功率常数为162.7,Metzner常数为19.0;搅拌雷诺数以及流体的流变指数对非牛顿流体搅拌流场的无因次速度、循环量数均有不同程度的影响;与双螺带搅拌桨相比,双螺带-螺杆搅拌桨能在一定程度上提高全槽平均剪切速率和平均速度.研究进一步认识了双螺带-螺杆搅拌桨的混合性能特点,为高黏流体搅拌桨的设计、应用以及开发新型搅拌桨提供了指导和参考.
The laminar flow field stirred by a double helical ribbon and screw impeller in a cylindrical vessel with computational fluid dynamics （CFD） was studied. The liquids are highly viscous Newtonian fluid and pseudoplastic non-Newtonian fluid. Good agreement between numerical simulation and experimental measurement of power consumption was obtained. The power constant of the double helical ribbon and screw impeller was 162.7 and the Metzner constant was 19.0. The Reynolds number and rheological index had some influence on the normalized velocity and circulation number for non- Newtonian fluid. Compared with double helical ribbon impeller,the double helical ribbon and screw impeller can increase the average shear rate and average velocity in the stirred tank to some extent. The research results promote the understanding of the mixing performance of the double helical ribbon and screw impeller and provide valuable instructions and references for the design, application and development of new type impeller in highly viscous fluid.
出处
《天津大学学报》
EI
CAS
CSCD
北大核心
2009年第10期884-890,共7页
Journal of Tianjin University(Science and Technology)
基金
天津市重点基金资助项目(07JCZDJC02600)
关键词
双螺带-螺杆搅拌桨
功率常数
轴向速度
流变指数
平均剪切速率
double helical ribbon and screw impeller
power constant
axial velocity
rheological index
average shear rate
