突扩管中高分子聚合物溶液湍流减阻的数值模拟  

Numerical simulation of turbulent drag reduction of polymer solution in a sudden expansion

作　　者：石若冉 张浩[1,2] 张志 李茂林 SHI Ruoran;ZHANG Hao;ZHANG Zhi;LI Maolin(School of Thermal Engineering,Shandong Jianzhu University,Jinan 250101,China;Shandong Co-innovation Center of Green Building,Jinan 250101,China)

机构地区：[1]山东建筑大学热能工程学院,山东济南250101 [2]山东省绿色建筑协同创新中心,山东济南250101

出　　处：《山东建筑大学学报》2023年第6期31-38,共8页Journal of Shandong Jianzhu University

基　　金：山东省专业学位研究生教学案例库项目(SDYAL20162);山东省研究生优质课程建设项目(SDYKC19117)。

摘　　要：高分子聚合物添加剂减阻是实现管道减阻的重要方法之一,突扩管是管道系统中常见的管件,研究添加剂在其中的流动特性对流动减阻和节能减排有着重要意义。文章利用数值模拟法通过Cross模型模拟高分子聚合物聚丙烯酰胺(Polyacry lamide,PAM)溶液在突扩管中的湍流流动,分析其流场、减阻规律以及回流区变化。结果表明:相同雷诺数时,PAM溶液工况的压力恢复最大值大于纯水工况的;随着雷诺数的增加,上游直管的减阻率先增大后减小;PAM溶液工况下突扩处局部阻力系数随着雷诺数的增加而增加,并表现出减阻效果,但其减阻率相较于直管段有明显减小;相同雷诺数下,PAM溶液中的回流区长度相比纯水的增加,这种变化及减阻效果的产生皆与湍动能的改变有关。The utilization of polymer additives for drag reduction stands as a crucial method in achieving reduced resistance in pipelines.As a common pipe fitting in the pipeline system,the study of the sudden expansion pipe flow holds significant importance for flow drag reduction and energy conservation.The numerical simulation method is used to examine the turbulent flow of the polymer PAM(polyacrylamide)solution in a sudden expansion pipe through the Cross model,and the flow field,drag reduction patterns and the variations in the recirculation zone are also analyzed.Results indicate that,the pressure recovery maximum of PAM solution is greater than that of water under the same Reynolds number.The drag reduction rate in the upstream straight pipe exhibits an initial increase followed by a decrease with the rise of Reynolds number.The local resistance coefficient of sudden expansion in PAM solution increases with the increase of Reynolds number,and shows a drag reduction effect,but the drag reduction rate is noticeably lower than that of the straight pipe.Furthermore,under the same Reynolds number,the length of the recirculation zone in PAM solution experiences an increased length compared to pure water.This alteration and the observed drag reduction effect are related to the change of turbulent kinetic energy.

关 键 词：突扩管 高分子聚合物 减阻 

分 类 号：TV134[水利工程—水力学及河流动力学]