用交替方向隐式迭代法计算铸件凝固过程的温度场

Alternative Direction Implicit Iteration Applied to Calculate Temperature Field for Casting in Solidification Process

为了提高薄壁、复杂铸件凝固过程数值模拟时的计算速度 ,将整个计算域分为砂型和铸件两个分区 ,用显式差分格式计算砂型中的温度场 ,用交替方向隐式迭代法计算铸件中的温度场 ;基于热焓法 ,采用源项线性化技术处理凝固潜热 ,以提高铸件温度场的收敛速度 ,采用变时间步长以提高铸件温度场的计算效率 .通过一个算例 ,证实本算法可提高薄壁铸件凝固过程数值模拟的计算效率 .

Efficiency of numerical simulation on solidification process for thin wall castings with complex shape can be improved by dividing the calculation domain into the casting and the sand mold regions. The temperature field in the latter is calculated by using the explicit FDM (Finite Difference Method), and that in the former by using the ADI (Alternative Direction Implicit Iteration). The nonlinear problem caused by latent heat release during solidification is solved by a linearization technique of source term based on the enthalpy method. The time step used in the casting region is increased stepwise to decrease the consumption of CPU time. The proposed method is validated by a calculation of temperature field for a real casting.