同步转子密炼机流体非线性流动和混合机理研究

The internal batch mixer with synchronous rotors is a new type equipment for polymer processing, in which the flow and mixing mechanisms are very complex. From current researches, we have known that the fluid in the internal batch mixer has typical nonlinear characteristics of flowing and mixing. Therefore, based on the traditional linear analysis, the present project focus on the study of the nonlinear flow and mixing mechanism in the internal batch mixer with synchronous rotors using the nonlinear dynamics theory. The project contents cover: the complex nonlinear dynamic behaviors of the fluid particles with typical trajectories in the mixer, such as periodic, quasi-periodic, chaotic or bifurcation will be studied by using nonlinear dynamics method. Moreover, the chaotic mixing characteristics and their evolutions in the internal batch mixer will be employed by means of Poincaré section, Lyaponuv index and area stretch and so on. The effect of the rotor geometries on the local and overall chaotic mixing of the internal batch mixer will be also studied. Especially, the relationship between the nonlinear dynamic characteristics of fluid particles and chaotic mixing intensity in the internal batch mixer will be revealed. A new design method for the rotor system of the internal batch mixer will be put forward based on the nonlinear theory. The significance of this project covers: the dynamic and nonlinear mechanisms of flowing and mixing in the internal batch mixer will be revealed. Furthermore, the new theory system of the design, optimization and scale-up for the internal batch mixer will be enlarged based on the nonlinear dynamic theory.

同步转子密炼机是一种新型聚合物加工设备，其流动和混合机理非常复杂。当前研究表明，密炼机流体的流动和混合均具有典型非线性特征。本课题拟在传统的密炼机流体线性分析的基础上，引入非线性动力学理论，开展同步转子密炼机流体非线性流动和混沌混合机理的理论和实验研究。内容包括：追踪具有典型运动轨迹的流体粒子的瞬时特征量场，采用非线性动力学分析方法，研究密炼机流体粒子经历的周期、拟周期、混沌或分岔等复杂非线性动力学行为。在此基础上，采用Poincaré截面、Lyaponuv指数和拉伸指数等研究密炼机流体的混沌混合特征和混沌演变过程，找出转子几何构型对密炼机局部和全局混沌混合的影响；揭示流体粒子的非线性动力学特性与密炼机内混沌混合强度之间的内在关联，提出基于非线性理论的密炼机转子设计新方法。研究意义：从本质上揭示密炼机内部动态的、非线性的流动和混合机制, 丰富基于线性技术的密炼机设计、优化和放大的理论体系。

同步转子密炼机是一种重要的聚合物加工设备，其流动和混合机理非常复杂。本项目在密炼机流体线性分析的基础上，引入非线性动力学理论，开展同步转子密炼机流体非线性流动和混沌混合的基础研究。①建立了多种转子密炼机流体流动和传热理论模型，采用粒子示踪法，利用分离尺度、混合指数、累积最大剪切和拉伸速率分布、停留时间分布（RTD）以及瞬时和平均混合效率等参数对不同转子密炼机内流体流动和混合特性进行对比分析。对双转子扰动下的密炼机流体的典型粒子的运动形态进行分析，计算了典型运动流体粒子（质点）的动态位移、速度、温度、压力、剪切速率等特征量。②采用非线性动力学分析方法，利用特征量的时程曲线、功率谱图、相图、Poincaré 截面等参数，分析了密炼机流体粒子的复杂非线性动力学行为，研究了流体粒子运动形态、受力状态和混合状态的突变机理以及对密炼机的分散混合和分布混合效率的影响机制。③采用Poincaré截面、Lyaponuv 指数和拉伸指数等研究了密炼机流体的混沌混合特征和混沌演变过程，分析了密炼机流体Smale马蹄映射的演变机理；找出了转子几何构型对密炼机局部和全局混沌混合的影响；揭示了流体粒子的非线性动力学特性对密炼机内混沌混合强度的影响关系。此外，采用拉格朗日拟序结构(LCS)的分析方法，对密炼机流体的输运和混合特性进行了初步探讨。