凝固过程中热传导的反问题

Inverse Problems of Heat Conduction during Solidification Process

在铸件的凝固过程中，铸件／铸型界面的热交换行为是影响凝固速度的关键因素、在讨论了几种求解热传导反问题的方法后，着重介绍了非线性估计法（Ｎｏｎｌｉｎｅａｒ ＥｓｔｉｍａｔｉｏｎＭｅｔｈｏｄ（ＮＥＭ）），同时也讨论了优化试验方案。以ＮＥＭ为理论基础，开发了两个程序并成功地应用到求解凝固过程中随时间而变化的金属／铸型界面热交换系数以及铸件、铸型中的温度场。

During solidification process of castings, the heat transfer behaviour at the metal-mold interface is a key factor which influences the solidification rate and hence the internal quality of castings. On the basis of discussion several methods of solving inverse problems of heat conduction, the-Nonlinear Estimation Method(NEM) is introduced in more detail and the optimum design of experiments is also discussed. Based on NEM principle, two programs were developed and applied successfully to compute the time-variable interfacial heat transfer coefficient at the interface between metal and mold during the solidification of castings as well as the temperature fields in castings and molds.