中文摘要：

针对一种新型双螺杆捏合机流场动力学特性进行数值模拟,建立双螺杆捏合机流场数值仿真模型,依据计算流体动力学（CFD）理论,对非牛顿流体进行三维、等温稳态数值分析,研究其在不同转速及中心距条件下压力场分布、速度场分布、最大剪切应力、物料流动速率等特性。研究结果表明：随着转速不断提高,流场最大压力、流量流动速率、最大剪切应力都会随之增大;螺杆转子对流场的最大剪切应力值随中心距的增加先增大后减小,而流动速率随中心距的增加不断增加,但当中心距增加到一定值后,流动速率会出现负值,物料出现严重回流,导致捏合机无法正常工作。研究结果为双螺杆捏合机结构参数的设计优化以及性能预测提供理论依据。

英文摘要：

The numerical simulation for dynamic characteristics of the flow field of a novel twin-screw kneader is carried out.The numerical simulation model of twin-screw kneader is established,and the three-dimensional,isothermal and steady numerical analyses of non-newtonian fluid are presented based on computational fluid dynamics（CFD）theory,and the characteristics under the conditions of different speeds and center distances,such as the distribution of pressure and velocity field,the maximum shear stress,the mass flow rate and so on,are studied.The research results show that：with increasing speed,the maximum flow pressure,the mass flow rate and the maximum shear stress increase;the maximum shear stress increases first and then decreases with increasing of center distance of the screw rotors,while the mass flow rate increases with increasing of center distance;but when the center distance reaches a certain degree,the mass flow rate is negative and the material appears serious reflux which can make the kneader stop working.The results provide a theoretical basis for performance prediction and reasonable designing for the novel twin-screw kneader.