平直管段不同宽度动边界环隙流场特性

为进一步探讨不同因素对动边界环隙流场水力特性的影响，采用试验和理论分析相结合的方法，对环隙宽度条件分别为25,20,15,10 mm的动边界环隙流场水力特性进行研究，试验采用筒装料管道水力输送管道车模型在管路系统平直段部分完成，流量条件为60 m3/h，管道车模型质量为750 g．研究结果表明:平直管段动边界环隙内部水流为紊流形态；环隙断面内各测点压力值随环隙宽度增大趋于集中，且同一断面内动边界管道车壁附近压力值较小，固定管道边壁处压力值较大；同一宽度条件下，轴向速度在车中断面内分布较车前、车后断面更为均匀，且呈现动边界附近速度值较大，固定边界附近值较小的环绕车体层状分布；环隙宽度为20 mm时，断面内轴向速度分布均匀性最好；各环隙宽度条件下，车身沿程各测试断面内周向速度均呈现不均匀分布．

Characteristics of annulus moving boundary flow in straight pipe segments of different widths

To further explore the influence of different factors on the hydraulic characteristics of the moving boundary annulus flow, through tests and theoretical analyses, annuluses with widths of 25,20,15,10 mm respectively were studied. The test was carried out in the straight pipe segment of the pipeline system, whose control volume is 60 m3/h, using barreled feed pipe carriage weighted 750 g. The research shows that the moving boundary annulus flow in straight pipe segment is turbulent morphology. Pressure values of measurement points in the annulus cross section tend to cluster as the width of the annulus increases. In the same section, pressure around the moving boundary of carriage is lower and pressure around the fixed pipe wall is higher. With the same width, the axial velocity sectional distribution is more uniform in the middle section than in the back or front. And the distribution is a layered one around the carriage body of which higher around the dynamic boundary and lower around the fixed border. When the width is 20mm, the axial distribution uniformity is best. Circumferential velocity shows uneven distribution in sections along the carriage under various conditions of different annulus widths.