Efficient numerical simulation of injection mold filling with the lattice Boltzmann method

Abstract

Purpose Lattice Boltzmann method (LBM) has made great success in computational fluid dynamics, and this paper aims to establish an efficient simulation model for the polymer injection molding process using the LBM. The study aims to validate the capacity of the model for accurately predicting the injection molding process, to demonstrate the superior numerical efficiency in comparison with the current model based on the finite volume method (FVM). Design/methodology/approach The study adopts the stable multi-relaxation-time scheme of LBM to model the non-Newtonian polymer flow during the filling process. The volume of fluid method is naturally integrated to track the movement of the melt front. Additionally, a novel fractional-step thermal LBM is used to solve the convection-diffusion equation of the temperature field evolution, which is of high Peclet number. Through various simulation cases, the accuracy and stability of the present model are validated, and the higher numerical efficiency verified in comparison with the current FVM-based model. Findings The paper provides an efficient alternative to the current models in the simulation of polymer injection molding. Through the test cases, the model presented in this paper accurately predicts the filling process and successfully reproduces several characteristic phenomena of injection molding. Moreover, compared with the popular FVM-based models, the present model shows superior numerical efficiency, more fit for the future trend of parallel computing. Research limitations/implications Limited by the authors’ hardware resources, the programs of the present model and the FVM-based model are run on parallel up to 12 threads, which is adequate for most simulations of polymer injection molding. Through the tests, the present model has demonstrated the better numerical efficiency, and it is recommended for the researcher to investigate the parallel performance on even larger-scale parallel computing, with more threads. Originality/value To the authors’ knowledge, it is for the first time that the lattice Boltzmann method is applied in the simulation of injection molding, and the proposed model does obviously better in numerical efficiency than the current popular FVM-based models.

Multi-Scale Numerical Approach to the Polymer Filling Process in the Weld Line Region

“…Recent decades had seen the fast progress in computer simulation methods, and now the numerical simulation has become a powerful method to improve the quality and processing of polymer products [12][13][14][15][16][17][18][19][20][21]. Wang et al [12] adopted FEM and the arbitrary Lagrangian-Eulerian (ALE) method to track the free surface of a polymer melt flow in the filling processing.…”

“…Li, et al [15] and Cao, et al [16] used FEM/FVM and FEM to solve the flow-induced stress, respectively. Deng, et al [17] pointed out that the Lattice Boltzmann method (LBM) can predict the injection molding process accurately. Farahani, et al [18] applied the smoothed particle hydrodynamics (SPH) technology to study numerically the hybrid process of sheet metal forming and injection molding.…”

Multiple-relaxation-time lattice Boltzmann simulation for adsorption processes of carbon dioxide in a fixed-bed

“…Comparing with the time-consuming and economical undesirable experimental method, the numerical simulation method, as a popular research tool from the microscopic to macroscopic scales (Huang et al , 2015; Deng et al , 2017a, 2017b; Ahmed et al , 2017), has attracted much interest for describing the dynamic adsorption behaviors in the fixed bed because of its simplification and high efficiency (Xu et al , 2013). Using the numerical solution of the coupling momentum-, mass-, and energy-conservation equations, the mathematical simulation studies have been applied to predict the complete dynamic processes including the flow, mashe/sheat transfer and adsorption behaviors in the fixed bed (Shafeeyan et al , 2014).…”

“…In the past decades, lattice Boltzmann (LB) model has been used to solve the complex fluid flow and heat/mass transfer problems successfully, because of several significant advantages compared with the conventional numerical methods, such as the simplicity of the algorithm, the linear convective operator, and the high efficiency for parallel performance (Kefayati et al , 2012; Deng et al , 2017a, 2017b). Recently, many attempts have been made to study the fluid transport and adsorption behaviors in the microscopic pore scale.…”

Simulation of dispersed phase evolution for immiscible polymer blends in injection molding

“…The morphological evolution mainly occurs in the blends preparation and product forming during the injection molding process. During this process, the morphology is determined by fluid properties and flow history, and finally, it affects the mechanical, optical and transport properties of the product (Zhang et al , 2015; Deng et al , 2017). There are already many studies on the morphological evolution during the compounding process (Lee and Chang, 2000); however, its impact in the latter injection molding process is not thoroughly understood (Fellahi et al , 1996; Son et al , 2001; Ghiam and White, 2004).…”