Particle Simulation for the Conveying Behavior of Granules in Grooved Bushing Extruders

提出的研究项目的目标是重新制定的数学描述的输送行为的沟槽衬套区的数值模拟的基础上。这使得能够在3D环境中检测进料部中颗粒的复杂运动，从而提高计算精度。在以往的研究项目中，它表明，无论是输送机制和充满活力的过程中的固体输送区的行为，可以很好地表示使用离散元方法。因此，该方法为该应用提供了依据。在模拟中，工艺和材料参数在中心组合设计的帮助下以及在螺杆通道和凹槽中的几何参数变化。通过改变槽角，还考虑了轴向或螺旋加工槽。在数值模拟支持的验证研究之后，将进行物理边界检测。因此，在使用光滑衬套区域进行模拟的情况下，可以看出，尽管反压导致颗粒积压，但第一螺杆螺纹可以部分填充。这导致了移位的压力分布，使得压力在整个进料段上不再增加。在足够高的旋转速度下，预计类似的槽系统。这也需要对现有的计算模型进行新的表述。所获得的结果最终将得到系统验证。在这里，已经开发了一个测试台，它将被调整到所需的槽衬套系统。通过现有的验证，可以对沟槽衬套区的输送过程进行广泛的描述。

The goal of the proposed research project is to reformulate the mathematical description of the conveying behavior in grooved bushing zones based on numerical simulations. This enables the possibility to detect the complex movements of the granules in the feed section in a 3D environment and thus improves the calculation accuracy. In previous research projects, it was shown that both, the conveying mechanisms and the energetic process behavior in the solids conveying area, can be well represented using the Discrete Element Method. Therefore, this method provides the basis for this application. In the simulations, process and material parameters are varied with the aid of a centrally composed design as well as geometrical parameters in the screw channel and grooves. Also axially or spiral machined grooves are taken into account by varying the groove angle. Next to verification studies supported by numerical simulations, a detection of physical boundaries will be performed. Thus, in the case of simulations with a smooth bushing zone, it can be seen that, despite a particle backlog, caused by the backpressure, the first screw flights can be partially filled. This leads to a displaced pressure profile, so that the pressure does not increase anymore over the entire feed section. Analogies are expected at sufficiently high rotational speeds on grooved systems. This also requires a new formulation of existing calculation models. The results obtained, will finally be systematically validated. Here, a test stand has been developed which will be adjusted to the desired grooved bushing system. With an existing validation, an extensive description of the conveying processes in grooved bushing zones is possible.