黏性泥沙含沙量对高速水流空化空蚀的影响  

Effect of cohesive sediment concentration on cavitation erosion in high velocity flow

作　　者：董志勇[1] 曾团 贾代鲁 韩岩 DONG Zhiyong;ZENG Tuan;JIA Dailu;HAN Yan(College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310023,China)

机构地区：[1]浙江工业大学土木工程学院,浙江杭州310023

出　　处：《浙江工业大学学报》2023年第3期349-354,共6页Journal of Zhejiang University of Technology

基　　金：国家自然科学基金资助项目(51979248)。

摘　　要：为探究黏性泥沙含沙量对高速水流空化空蚀影响的机理,在小型循环式水洞中配制了不同含沙量的挟沙水流,用红外测沙仪测定了挟沙水流的含沙量,用压力数据采集系统量测了空化区及空蚀区各测点的压强,并求出空化数以分析空化发生的条件。为研究不同含沙量和不同流速情况下砼试件的空蚀情况,制作了7 d龄期、配合比为水灰比W/C=0.4,灰砂比C/S=1.5的砼试件,进行4 h的空蚀试验,空蚀量以砼试件每小时重量损失表示。试验结果表明:在黏性泥沙含沙量S=0~50 kg/m^(3)情况下,含沙量对空化空蚀的影响存在一个临界含沙量S=30 kg/m^(3),当含沙量S<30 kg/m^(3)时,砼试件的空蚀量随含沙量的增加而增大,表明含沙量对空蚀具有促进作用;当含沙量S>30 kg/m3时,砼试件的空蚀量则随含沙量的进一步增加而减小,表明含沙量对空蚀具有抑制作用。当流速增大时,空蚀程度也随之增大。In order to explore the influential mechanism of sediment concentration on cavitation and cavitation erosion in high velocity flow,different sediment-laden flows are prepared in a small circulating water tunnel.The sediment concentration of sediment-carrying flow is measured with an infrared sand meter,a pressure data acquisition system is used to measure the pressure at each measuring point in the cavitation zone and the cavitation erosion zone,and the cavitation number is calculated to analyze the cavitation level.To test the cavitation erosion of concrete specimens with different sediment concentrations and different velocities,the concrete specimens with mix proportion of W/C=0.4 and C/S=1.5 at a age of 7 days are cast for the four-hour cavitation erosion experiment and the cavitation erosion rate is represented by the weight loss of concrete specimens per hour.The experimental results show thatthere is a critical sediment concentration of S=30 kg/m^(3) as S=0-50 kg/m^(3) are carried out to investigate the effect of cohesive sediment concentration on cavitation erosion.When S<30 kg/m^(3),the cavitation erosion rate of concrete specimens increases with the increase in sediment concentration,indicating that the sediment concentrationpromotes cavitation erosion.When S>30 kg/m 3,the cavitation erosion rate decreases with a further increase in sediment concentration,exhibitingthat the sediment concentration inhibits cavitation erosion.With an increase in flow velocity,the cavitation erosion degree also increases.

关 键 词：空化空蚀 黏性泥沙 含沙量 高速水流 砼试件 

分 类 号：TV131.3[水利工程—水力学及河流动力学]