确定金属型铸造界面传热系数方法的研究

铸造凝固过程数值模拟中通常用界面传热系数表示热阻的影响,在诸多影响模拟精度的因素中,该系数起主导作用。为提高模拟精度,以ANSYS软件为平台,在测温试验的基础上,考虑铸件与铸型的不同接触位置以及不同界面传热系数对模拟结果的影响,采用0.618黄金分割法选取了该系数;应用最小二乘法建立起界面传热系数与时间关系的数学模型,并对金属型铸造凝固过程的温度场进行了模拟,将模拟结果与试验结果做了对比分析,得到了合理的温度分布。研究的结果为获得精确的界面传热系数提供了一种研究方法。

Methodological Research for Defining Interface Heat Transfer Coefficient in Metal Mould Casting

In the process of numerical simulation of casting solidification,the interface heat transfer coefficient was traditionally used to reflect the influence of the heat resistance.Among several factors to make the precision more precisely,this coefficient played an important role in affecting the precision.In order to determined a higher precision,the ANSYS software served as a platform.Basing on the experiment of temperature measurement,the 0.618 method was adopted to select the coefficient,considering the different meet places between the cast and the mould,and the effects made by different interface heat transfer coefficient.By using the least-squares method,a mathematic mode of the realization between time and the interface heat transfer coefficient was set up in order to simulate temperature fields of metal mould casting solidification.And then,a conclusion that a reasonable temperature distribution can be made by comparing the simulation result with the testing data.The result provides a method to get the accurate interface heat transfer coefficient.