关键词: 注塑, 充填, 温度, 三维数值模拟

Abstract:

In the filling stage of plastic injection molding, the energy equation is dominated by convection.The simulation of temperature with the classical Galerkin finite element method in a fixed element might be unstable and oscillatory if time step is unreasonable.To get the reliable solution, the algorithm must deal with both convection and conduction, which requires highly different time scales.For this reason, the energy equation was solved by an operator-splitting method. First, the convective part of the problem was solved, and then the conduction term and source term were solved.In this way, particularly effective numerical schemes were used.As this approach used sub-time steps for the convection term, which was much smaller than that for the conduction term, the unstable result caused by convection could be solved consequently.In addition, the lumped mass heat capacity matrix was used to deal with the transient item, which reduced non-physical oscillations that the consistent mass heat capacity matrix possibly led to.For the given examples, the simulation results illustrated that the scheme in this paper had better accuracy.

Key words: 注塑, 充填, 温度, 三维数值模拟