焊接温度场中复合换热系数的分析

Analysis of the combined coefficient of heat transfer in the welding temperature field

在焊接温度场的模拟中,换热系数与焊件的冷却过程密切相关.根据传热学的相似理论,计算随时间变化的对流和辐射系数,将其转换为复合换热系数,实时地加入到温度场的计算过程中去,模拟得到焊件在空气中自然冷却时的温度场.与采用恒定换热系数得到的结果比较,文中提出的确定和施加换热系数的方法更为合理.

The coefficient of heat transfer is closely related to the cooling process while modeling welding temperature field. According to the classical heat transfer theory, the combined coefficient, i.e. convection coefficient adding with radiation coefficient, is determined by similarity theory in this paper. Because the combined heat transfer coefficient is expressed by a function of temperature, and the welding temperature fieM is time-dependent, it is surely to add the heat transfer loads timely. Compared with the model m which the constant transfer coefficient is used, it is found that the analysis method provided in this paper is more reasonable and suitable.