摘要
目的在明渠条件下分析挟沙水流对金属波纹管内表面镀层的冲蚀情况,明确冲蚀的机理及特征。方法采用自主搭建的循环试验水槽平台对金属波纹管涵进行挟沙水流的冲蚀试验。将波纹管设计为A、B、C管段,根据水的流速变化,选取各管段波纹截面及测点。根据不同粒径区间,在0.12、0.24、0.47 mm工况下,冲蚀时间达到200、400、600 h时分别测量各测点,得到内表面镀层在不同工况、不同位置的冲蚀量。结果采用扫描电镜观察0.47 mm工况下B2波纹段的冲蚀形貌,结果表明,波峰和迎水面位置的冲蚀坑紧密分布,镀层的冲蚀现象最为严重。在1个波纹周期内,沿着水流方向,波峰位置的冲蚀量相对最大,且迎水面镀层的冲蚀量比对称位置背水面的冲蚀量大;在垂直于水流方向的横断面上,中轴线位置的冲蚀量相对最大,两侧逐渐减小。在同等条件下,沙粒粒径为0.47 mm工况下的冲蚀率相对最大,其中T_(0)断面处的最大冲蚀速率达到了6.31μm/100 h。结论波纹管内表面镀层因颗粒冲蚀,镀层减薄,直至消失,进而导致波纹管的失效速率加快。波峰位置的冲蚀速率相对最大,以波峰为对称轴,迎水面的冲蚀速率大于对应位置背水面的冲蚀速率。冲蚀速率与沙粒粒径呈线性关系,冲蚀速率随着沙粒粒径的增大而增大。壁面冲蚀速率与近壁面沙粒速度呈幂指数关系,不同横断面的速度指数不同,速度指数最大值出现在波峰断面。
Corrugated metal pipe is a corrugated pipe with steel as the base and galvanized,aluminum and other materials on the surface.Because it has the characteristics of light weight and strong resistance to foundation deformation,it is widely used in drainage systems such as bridges and culverts.The recent failure cases of corrugated metal pipe at home and abroad show that the erosion damage of the inner wall coating under the condition of gentle slope will also seriously affect the service life of the pipe.This work aims to study the erosion problem of sediment laden flow on the inner surface coating of corrugated metal pipe under the condition of open channel through the physical model test,so as to clarify the erosion mechanism and characteristics.In this paper,the self-built circulating test tank platform was used to carry out the erosion test of sediment laden flow in corrugated metal pipe.The bellows was designed as three parts of pipe section A,B,and C.According to the change of flow velocity,the corrugated cross section and measuring point of each pipe section were selected.When the erosion time reached 200 h,400 h and 600 h under the working conditions of 0.12 mm,0.24 mm and 0.47 mm,the erosion amount of the inner surface coating at different positions under different working conditions was obtained.Scanning electron microscope was used to observe the erosion morphology of the B2 section under the 0.47 mm working condition,and it was found that the erosion pits at the wave crest and the upstream surface were closely distributed,and the erosion of the coating was the most serious.Due to the influence of the velocity of sand particles near the wall and the uneven sand content,in a ripple period along the direction of the water flow,the erosion amount at the wave crest was the largest.On the upstream and downstream surfaces with the wave crest as the symmetry axis,the erosion rate of the upstream surface was greater than that of the downstream surface at the corresponding position.On the cross-section perpendicul
作者
陈智华
仝玉栋
张传杰
刘延波
陈荣旗
CHEN Zhi-hua;TONG Yu-dong;ZHANG Chuan-jie;LIU Yan-bo;CHEN Rong-qi(Harbin Engineering University,Harbin 150001,China;Offshore Oil Engineering Co.,Ltd.,Tianjin 300451,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2022年第11期205-214,共10页
Surface Technology
基金
科技部重点研发计划(2018YFC0.10500)。
关键词
金属波纹管
冲蚀磨损
挟沙水流
明渠条件
回归拟合
冲蚀试验
corrugated metal pipe
erosion wear
sediment-laden flow
open channel flow condition
regression fitting
erosion experiment
