双螺杆捏合机转子型线设计与数值模拟

Rotor Profiles Design Method and Numerical Simulation for Twin-screw Kneader

利用曲面共轭原理建立双螺杆捏合机转子型线设计与螺杆转子共轭曲面啮合方程的数学模型,提出一种可对高黏度物料进行输送、混合及塑化作用的新型双螺杆捏合机螺杆转子型线,给出转子螺旋副组成齿型线参数方程,进行转子结构设计。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理论,对非牛顿流体流动进行三维、等温稳态有限元数值分析,研究其在不同转速及中心距条件下流场压力场分布、速度场分布、最大切应力、物料流动速率等特性;依据流固耦合理论,求解捏合机内部流体和双螺杆转子结构耦合方程,研究不同工况下流体压力和扭矩对螺杆转子应力和变形影响的变化规律。研究结果为双螺杆捏合机转子型线、结构参数的设计以及工艺参数的合理设定提供理论依据。

The profile curve design method and the mathematical model of conjugate surfaces of twin-screw kneader used for high viscosity material mixing, transportation and malaxating are established according to principle of gear engagement. One novel twin-screw kneader and the equations of the profile curves of the rotors as well as the rotor design are put forward, and the female and male rotor structures are designed. The working principles of the twin screw kneader are analyzed. The numerical simulation for dynamic characteristics of the flow field of the twin-screw kneader is carried out. The numerical simulation model of twin-screw kneader is established, and the three-dimensional, isothermal and steady numerical analysis of non-newtonian fluid is 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. Based on Fluid-solid coupling theory, the effect of different working conditions, such as fluid pressure, torque, on the twin-screw rotors＇ stress and deformation is studied by solving the fluid solid coupling equations between internal fluid of kneader and the twin-screw rotors. The results provide a theoretical basis for reasonable designing and optimization of technical parameters for the novel twin-screw kneader.