Numerical investigation on the influence of air flow in a die filling process
Numerical investigation on the influence of air flow in a die filling process
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模具填充过程中气流影响的数值研究
DOI：
10.1016/j.jtice.2017.11.031
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
M. Sakai
中科院分区：
文献类型：
--
作者：
H. Yao;Y. Mori;K. Takabatake;X. Sun;M. Sakai
充模是化工材料科学与技术中广泛涉及的一个重要制造过程。在优化模具填充过程中需要应用数值技术。离散单元法（DEM）被广泛用于模拟颗粒在模具中的流动。然而，现有的DEM有一个问题，关于在移动鞋系统中的空气流的计算，即使DEM与计算流体动力学（CFD）耦合。这是因为模拟具有移动边界的气固流动需要非常复杂的算法。为了解决这一问题，提出了先进的DEM-CFD方法来计算颗粒在整个充型过程中与空气的相互作用。在先进的DEM-CFD方法中，采用紧凑算法来模拟移动边界系统中的气固流动，其中壁面边界采用符号距离函数和浸没边界方法来模拟固相和液相。验证测试进行，以显示先进的DEM-CFD方法的充分性。结果表明，模拟结果与实验结果吻合较好，因此，我们的数值方法是足够的再现实际的模具填充过程。
Die filling is an important manufacturing process that is widely involved in material science and technology in chemical engineering. Application of numerical technologies is desired in optimizing a die filling process. The Discrete Element Method (DEM) is widely used to simulate granular flows in die filling. However, the existing DEM has a problem regarding the computation of air flow in a moving shoe system, even though the DEM is coupled with computational fluid dynamics (CFD). This is because that the simulation of a gas-solid flow with a moving boundary requires an extremely complex algorithm. In order to solve this problem, The Advanced DEM-CFD method is proposed to calculate granular particles interacting with air meanwhile during the whole die filling process. In the Advanced DEM-CFD method, a compact algorithm is employed to simulate a gas-solid flow in a moving boundary system, where wall boundary is modeled by Signed Distance Function and Immersed Boundary Method for solid phase and fluid phase. Validation tests are performed to show the adequacy of the Advanced DEM-CFD method. The results show that the simulations well agree with the experiments, and hence our numerical approach is adequate to reproduce actual die filling processes.