Automated design and optimisation of dynamic mixing and shear elements for single-screw extruder

单螺杆挤出机动态混合和剪切元件的自动化设计和优化

基本信息

批准号：
327074219
负责人：
Professorin Dr.-Ing. Stefanie Elgeti
金额：
--
依托单位：
Institut für Kunststoffverarbeitung (IKV) in Industrie und Handwerk an der RWTH Aachen
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/327074219?language=en
关键词：
Automated design optimisation dynamic mixing

项目摘要

Mixing and shear elements are increasingly used in single-screw extruders due to the demand for ever higher throughputs while maintaining plastics melt homogeneity. The task of mixing and shear elements is to disperse and distribute additives and fillers evenly in the plastics melt and homogenise the melt thermally. To date, the design of mixing elements is based on the experience of the designer. By contrast, a much more detailed insight into the mixing process can be achieved via three-dimensional simulations. However, available approaches for the computation of mixing operations in extruders often have great limitations and are generally used only for exemplary evaluation of individual mixing elements. Difficulties arise on the one hand in the choice of a suitable mixing index. On the other hand, the high effort in the numerical optimisation of mixing elements is an obstacle to the use of flow simulations in the design phase. So far, there is no software for the automated optimisation of mixing elements available.Against this background, it is the goal of this project to develop an optimisation framework that enables the automated simulative design and optimisation of mixing and shear elements in single-screw extruders. With this framework knowledge about the ideal mixing element geometry in dependence of the mixing task will be acquired. For this purpose, the existing in-house flow solver of the applicant CATS will be modified in order to enable the non-isothermal simulation of the mixing processes in the melt zone of the extruder. The modified solver will then be integrated into an optimisation routine. Meanwhile, the IKV will identify suitable boundary conditions for a realistic three-dimensional simulation of complex mixing elements using a comparison of simulation results and experimental reference data. In the next step, the IKV will simulatively compare different mixing indexes and identify those indexes that are particularly well suited for the design of mixing elements. These mixing indexes are combined into a single objective function in the optimisation framework. In addition, the IKV will simulatively analyse and characterise the cause-effect relationships between the mixing element geometry and the resulting flow conditions. This gain in knowledge will be incorporated into the optimisation framework and facilitate the identification of suitable mixing element sections that will be enabled for the optimisation. Following its successful implementation, the optimisation framework will be used by IKV and CATS in order to design and optimise a mixing element sequence, which is suitable for a very wide range of applications. Thedeveloped mixing element sequence will finally be manufactured and used for the practical validation of the optimisation framework.

由于对更高的吞吐量的需求在维持塑料融化的同质性的同时，混合和剪切元件越来越多地用于单螺钉挤出机中。混合和剪切元件的任务是将添加剂和填充物均匀地分散和分配到塑料中，并热使融化。迄今为止，混合元素的设计基于设计师的经验。相比之下，可以通过三维模拟获得对混合过程的更详细的见解。但是，用于计算挤出机中混合操作的可用方法通常具有很大的局限性，通常仅用于对单个混合元件的示例性评估。一方面，在选择合适的混合指数时出现了困难。另一方面，混合元素的数值优化的高度努力是在设计阶段使用流程模拟的障碍。到目前为止，还没有用于自动优化混合元素的软件。在此背景下，该项目的目的是开发优化框架，该框架可以实现单螺旋式挤出机中的混合和剪切元素的自动模拟设计以及优化。借助有关理想混合元素几何形状的框架知识，将获得混合任务的依赖性。为此，将修改申请人猫的现有内部流动求解器，以实现挤出机熔体区域中混合过程的非等温模拟。然后，修改后的求解器将集成到优化例程中。同时，IKV将使用模拟结果和实验参考数据的比较来确定对复杂混合元件进行现实的三维模拟的合适边界条件。在下一步中，IKV将模拟比较不同的混合索引，并识别特别适合设计混合元素的索引。这些混合索引在优化框架中合并为单个目标函数。此外，IKV将模拟分析和表征混合元件几何形状与所得流条件之间的原因效应关系。知识中的增益将纳入优化框架中，并促进将启用合适的混合元件部分的识别，以进行优化。成功实施后，IKV和CAT将使用优化框架，以设计和优化混合元件序列，该序列适用于非常广泛的应用程序。最终将制造并将其用于优化框架的实际验证。