摘要：在高黏高固含量同步糖化与水解发酵反应中，随着反应进行，体系黏度逐渐降低，本文针对上述复杂变黏反应，设计了一种新型双轴异速搅拌桨。本文采用流体力学计算法，利用ANSYS分析软件对异速复合叶轮搅拌槽内的流体运动情况进行仿真模拟。选择以转速比、黏度和桨叶旋转方向为研究因素，分别设置转速比条件为0.5，1，2，4，6，10，14，18，黏度条件为1，3，4，6，10，14，16，20Pa·s，螺带桨旋转方向为顺时针、逆时针的条件（内外桨叶同向旋转），得到各种条件下的流体流场速度分布、剪切速率分布、最大剪切率等数据。计算结果表明，异速复合叶轮搅拌槽内在不同转速比的情况下，转速比越高，流体流动速度越快，平均剪切速率也越高；黏度越低，流体流动速度越快，平均剪切速率也越高，但并非呈线性变化；内外桨叶旋转方向的变化会影响流体流动的速度方向，且随着转速比的增大，流体运动方向会发生改变。

关键词： 异速复合；转速比；计算流体力学；流场特性；黏度

Numerical Simulation of Flow Field Characteristics in Coaxial Stirred Tanks 

Abstract：In the simultaneous high-viscosity and high-solid saccharification and hydrolysis reaction, the viscosity of the system gradually decreases with the progress of the reaction. In this paper, a new type of dual-axis all-speed stirring paddle is designed for the complex and viscous reaction. In this paper, the fluid dynamics calculation method is used to simulate the fluid movement in the agitator tank with all-speed compound impeller using ANSYS software. The speed ratio was set at 0.5,1,2,4,6,10,14,18, and the viscosity at 1,3,4,6,10,14,16, 20 Pa·s,. The direction of HR was set at clockwise and counterclockwise. The fluid flow velocity distribution, shear rate distribution, the maximum shear rate and other data under various conditions were obtained. The calculated results show that under different speed ratios in the coaxial agitator tanks, the higher the speed ratio is, the faster the fluid flow speed is, and the higher the average shear rate; the lower the viscosity, the faster the fluid flow rate is and the average shear strain rate is also higher, but it is not a linear change; changes in the impeller rotation direction affect the velocity of fluid, The direction of the fluid flow changed as the 

speed ratio increases.

Key Words：coaxial；speed ratio；computational fluid dynamics；flow field characteristics；viscosity

目  录

1  绪论 1

1.1  计算流体力学(CFD)技术概况 1

1.2  反应器的数值模拟方法 1

1.2.1  多重参考坐标系法（MRF） 1

1.2.2  滑移网格法（SM） 2

1.3  搅拌器计算流体力学研究现状 2

1.4  小结 3

1.5  研究的目的、意义和内容 4

1.5.1  研究目的 4

1.5.1  研究意义 4

1.5.3  研究内容 4

2  数值模拟方法 4

2.1  控制方程 4

2.1.1  连续性方程 5

2.1.2  动量方程 6

2.2  旋转桨叶的模拟 7

2.3  数值方法 ANSYS异速复合叶轮搅拌槽内流场特性的数值模拟:http://www.chuibin.com/jixie/lunwen_205604.html