Abstract: The direct discontinuous Galerkin (DG) method was applied to calculate the soil instable temperature field of underground heated pipeline. This method applied partial integration from each computational cell for the heat transfer equation and obtained weak formulation.The direct DG was obtained by building appropriate numerical flux. The ordinary differential equations were gained by solving spatial discretization by means of the explicit Euler method. Through the calculation of the radial temperature field of heated pipeline ,its results coincide with other references'. Thus means that the direct discontinuous Galerkin method is an efficient and accurate numerical method for the calculation of instable temperature field.

Key words: rect discontinuous galerkin method , Oil transmission pipeline , Soil temperature field

摘要： 采用直接间断有限元方法(直接间断Galerkin(DG)方法)计算了埋地输油管道周围的非稳态温度场。
该方法在每个单元对热传导方程分部积分得到弱形式,通过构建合适的数值流量得到直接间断Galerkin格式;用显
式Euler方法求解空间离散得到常微分方程组。对热油管道径向温度场进行了计算,其结果与其他文献的结果相吻
合,说明直接间断有限元方法在计算非稳态温度场中是一个有效的、精确的数值方法。

关键词: 直接间断有限元方法 , 输油管道 , 土壤温度场