Spectral method and spectral element method are both used in the present dns . the flow is developed from an initial velocity field whose mean and root mean square values are fitted to the experimental data . the reynolds number of the flow is 2250 based on the mean velocity and the radius of the pipe 本文在空间离散上采用谱方法和谱元法的结合，通过在圆管层流速度剖面上叠加随机扰动作为初始场的方法，计算了管长为，平均雷诺数为2250的光滑圆管内的湍流流动，建立了圆管内较低雷诺数下速度场和压力场的数据库。
