注塑成型三维流动的数值模拟

建立了非等温、粘性、不可压缩、非牛顿流体流动的控制方程。为了避免同时求解耦合的压力场、速度场，本文通过修改Galerkin方法的变分方程，导出了关于压力场的拟Poisson方程，用迭代法独立地求解连续性方程、动量方程，并进行速度一粘度迭代求出最终的压力场、速度场。由于直接使用Galerkin方法求解能量方程容易引起温度场的振荡，本文采用隐式格式及“上风”法离散能量方程，用超松驰迭代法求解温度场的代数方程组。比较了模拟结果与等温管道流动的解析解及法兰的实际注射结果，算例表明本文方法可以预测注射成型流动过程中的一些重要特征。与传统Galerkin方法相比，本文方法可以减少内存，提高数值方法的稳定性。

Numerical simulation for 3D flow in injection molding

The governing equations are established for the viscous,incompressible,non-Newtonian fluid under non-isothermal conditions.In order to avoid the simultaneous determination of the coupled velocity and pressure,this paper deduces a Poisson-like equation about pressure by modifying the variational formulation and solves the components independently at any given time step.The iterative procedure is employed both for velocity-pressure and velocity-viscosity solutions of the coupled equations.Traditional Galerkin method may brings oscillations of temperature solution when directly applied to energy equation.A mixed implicit and up-wind approach is proposed to discrete the energy equation.The over relax iteration is employed to get the solution of the discreted algebraic liner equations.The proposed 3D technique is validated with analytic solutions of isothermal flow in pipe and also agreeable with the experimental results of flange filling.It can successfully predict the flow features in injection molding.The approach used in this paper can reduce memory needs in simulation,enhance the stability of numerical scheme compared with conventional Galerkin method.