Abstract With the rapid development of traffic infrastructure in China, the problem of crystal plugging of tunnel drainage pipes becomes increasingly salient. In order to build a mechanism that is resilient to the crystal plugging of flocking drainage pipes, the present study used the numerical simulation to analyze the two-dimensional flow field distribution characteristics of flocking drainage pipes under different flocking spacings. Then, the results were compared with the laboratory test results. According to the results, the maximum velocity distribution in the flow field of flocking drainage pipes is closely related to the transverse distance h of the fluff, while the longitudinal distance h of the fluff causes little effect; when the transverse distance h of the fluff is less than 6.25D (D refers to the diameter of the fluff), the velocity between the adjacent transverse fluffs will be increased by more than 10%. Moreover, the velocity of the upstream and downstream fluffs will be decreased by 90% compared with that of the inlet; the crystal distribution can be more obvious in the place with larger velocity while it is less at the lower flow rate. The results can provide theoretical support for building a mechanism to deal with and remove the crystallization of flocking drainage pipes.

中文翻译：

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隧道内植绒排水管二维流场分布特征

摘要 随着我国交通基础设施的快速发展，隧道排水管道晶体堵塞问题日益突出。为建立植绒排水管晶体堵塞的弹性机理，本研究采用数值模拟方法分析了不同植绒间距下植绒排水管的二维流场分布特征。然后，将结果与实验室测试结果进行比较。结果表明，植绒排水管流场中的最大速度分布与绒毛横向距离h密切相关，而绒毛纵向距离h影响不大；当绒毛横向距离h小于6.25D（D为绒毛直径）时，相邻横向绒毛之间的速度将提高10%以上。而且，上下游绒毛的速度比入口速度降低90%；晶体分布在流速较大的地方更明显，而在流速较低的地方则较少。研究结果可为建立处理和去除植绒排水管结晶的机制提供理论支持。