铸铝件凝固过程三维瞬态温度场的数值模拟

Numerical simulation of 3D transient temperature field in aluminum alloy solidification process

采用有限元数值算法,针对一具体铝合金砂型铸造工艺,充分考虑材料和边界条件等参数的非线性特征,使用等价比热容法处理结晶潜热,对凝固过程进行了三维瞬态温度场的数值模拟。通过铸造测温实验,得到了不同位置的测温曲线,且每个位置的测温曲线与相应的计算温度曲线基本吻合,从而证明数值模拟的精度和有效性;对于各测温点的计算温度与测量温度的偏差情况,从测温误差和有限元模型两方面进行分析,提出降低热电偶测温误差和提高数值模拟精度的具体措施。

The 3D transient temperature field was solved to the aluminum alloy solidification process by employing finite element method. The nonlinear feature of material properties and boundary condition was considered and the equivalent specific heat method was adopted to treat the latent heat. The temperature measurement experiment was done and the temperature measurement curves were acquired in different location, and the measurement temperatures were basically identical with the corresponding calculated ones. Thus, it verifies the accuracy and validity of numerical simulation. The errors between the measurement temperatures and the calculated ones were analyzed from the viewpoint on both the measurement error and the finite element model. Moreover, the detailed measurements were proposed to decrease the measurement errors and improve the simulation accuracy.