3D Flow Simulation for Viscous Nonisothermal Incompressible Fluid in Injection Molding

Abstract

The major drawbacks of the Hele-Shaw approximation, commonly used today as a means of simplifying the simulation of the injection molding process, are the inherent loss of the ability to predict important physical phenomena and the ambiguity involved in the definition of a midplane. With the objective of eliminating many of these problems, a fully three-dimensional mold filling simulation program has been developed. The governing equations are in terms of Navier-Stokes problems for the viscous, incompressible, nonisothermal, and non-Newtonian fluid. To avoid the simultaneous determination of the coupled velocity and pressure, this article introduces an iterative method that at any given time step solves the components independently. This method reduces memory needs in simulation and enhances the stability of numerical scheme. In addition, this article also presents a mixed implicit and ''up-wind'' scheme to discrete the energy equation. It can overcome the spatial oscillations of temperature in numerical simulation. Good agreements with both analytic solution and the actual processes are found in the current investigation. This method can successfully predict the flow features in injection molding.

Modeling and Optimization of the Injection‐Molding Process: A Review

“…It is intended to focus on the main features of the methods, instead of giving deep and detailed descriptions of the models previously published in the literature. Filling, Packing-Holding, and Cooling 24 No No Yes 2D Chung and Kwon 27 Yes No No 2D Chiang et al 9 Yes Yes Yes 2D Wang et al 29 Yes 37 Yes No No 3D Zheng et al 38 Yes Yes Yes 3D Chang and Yang 40 Yes No No 3D Rajupalem et al 43 Yes Yes No 3D Talwar et al 44 Yes Yes No 3D Ilinca and Hétu 10 Yes Yes Yes 3D Yang et al 41 Yes Yes Yes 3D Khayat et al 45 Yes No No 3D Cao et al 46 Yes No No 3D Hassan et al 42 No No Yes 3D…”

“…Different 2D and 3D examples were suggested to validate the approaches presented and to illustrate its capabilities. 10,[43][44][45][46] Summarizing, it is generally recognized that computer aided engineering (CAE) simulations for IM can be outlined back to the 49 No Yes Donovan 50 Yes Yes Lipshitz et al 51 No Yes Rauwendaal 52 No Yes Potente et al 53 Yes Yes Yung and Xu 54 No Yes Yung et al 55 No Yes Steller and Iwko 56 No Yes Fernandes et al 58 Yes Yes pioneering research done by Kamal and Kenig 8 on the developments of the theoretical principles and fluid mechanics models. To apply 1D flow representations to simulate polymer flow in typically complex mold cavities, a "branching flow" approach was proposed and implemented.…”

“…In these works, both finite‐element and finite volume methods were used to predict velocities, pressure, temperature fields, position of the flow front, and residual stresses for the 3D mold filling, packing, and cooling of the IM process. Different 2D and 3D examples were suggested to validate the approaches presented and to illustrate its capabilities …”