壁面微沟槽对输油管道阻力特性影响的数值研究

Numerical Study on the Influence of Wall Surface Microgroove on the Resistance of Oil Transmission Pipeline

针对壁面微沟槽的减阻问题,通过数值模拟的方式,探究减阻效果出现的原因。首先对数值模拟的相关参数进行了描述,对常见的2种尺寸三角形沟槽进行了减阻效果对比,从而优选出最佳的三角形沟槽尺寸;然后对最佳的三角形沟槽尺寸和最佳流动速度进行流场分析,并与光滑壁面输油管道的流场进行了对比,查找出三角形沟槽具有减阻效果的原因。研究表明:当三角形沟槽尺寸为h=s=0.15mm、流速为1.6m/s时,管道的减阻效果达到最佳,最大减阻率可以达到7.8%;三角形沟槽位置处流动平稳、速度脉动相对较小、存在二次涡以及雷诺应力相对较小是三角形沟槽具有减阻效果的主要原因。

In view of the drag reduction problem of wall surface micro- groove, the reasons for the drag reduction effect are explored by numerical simulation. The relevant parameters of numerical simulation are first described, and the common two- dimensional triangular grooves are compared from the respect of drag reduction effect, and the optimal triangular groove size is selected. Then the best triangular groove size and optimal flow rate are used to analyze flow field,and compared with the flow field of smooth wall oil transmission pipeline, and the reason for the drag reduction effect of triangular groove is found. The research shows that when the size of triangular groove is h=s=0.15 mm and the flow rate is 1.6 m/s,the drag reduction effect of pipeline is optimal,and the maximum drag reduction rate can reach 7.8%. The flow at the triangular groove is stable, the velocity pulsation is relatively small, the presence of secondary vortices and the relatively small Reynolds stress are the main reasons for the drag reduction effect of triangular grooves.