泥沙性质对高速水流消失空化数的影响  

Effect of sediment properties on desinent cavitation numberin high velocity flow

作　　者：董志勇[1] 李丹[1] 徐瀚冉 黄桢蕾 DONG Zhiyong;LI Dan;XU Hanran;HUAN Zhenlei(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310023

出　　处：《浙江工业大学学报》2024年第5期473-478,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：消失空化数是表征高速水流空化状态的重要判别数,水流含泥沙后对消失空化数的影响引起了研究者的关注。利用自主研发的小型循环式水洞试验装置,对不同含泥沙条件下与清水介质下的水洞喉部(即空化区)消失空化数进行了试验研究。通过配制不同泥沙质量浓度、泥沙粒径、泥沙颗粒级配和泥沙矿物成分等挟沙水流,调节分流阀门降低水流流速,由动态压力数据采集系统(YE6263)实时测量空化区压强,直到压强由负压变为正压的临界压强(相应的消失空化数压强)。研究结果表明:在不同泥沙质量浓度的条件下,循环式水洞喉部的消失空化数随泥沙质量浓度的增加先增大后减小,与清水对比,表现出先促进后抑制空化的发生;在不同泥沙粒径的条件下,喉部消失空化数随粒径的增大而增大,说明泥沙粒径的增大促进了空化的提前发生;在不同泥沙级配的条件下,喉部消失空化数随小于某一粒径泥沙质量分数的增大而增大,表现出随着小于某一粒径泥沙质量分数的增大越容易发生空化;在不同泥沙矿物成分条件下,喉部消失空化数随矿物成分摩氏(Mohs)硬度的增大而增大,说明矿物成分硬度越大越促进空化的发生。The desinent cavitation number is an important discriminant number to represent the cavitation status of high velocity flow,and much attention is currently paid to the influence of sediment-laden flow on the desinent cavitation number.In order to study the effects of different sediment concentrations,sediment grain sizes,sediment gradations and sediment mineral compositions on the desinent cavitation number in high velocity flow,a self-developed small circulating water tunnel test device was used to experimentally investigate the desinent cavitation number of the throat(cavitation zone)in the tunnel under different sediment-laden conditions and clear water medium.By preparing the sediment-laden flows with different sediment concentrations,sediment grain sizes,sediment grain gradations,and sediment mineral compositions,the dividing valve was adjusted to reduce the flow velocity,and a dynamic pressure data acquisition system(YE6263)was used to real-timely measure the pressure in the cavitation zone until the pressure turns from negative to positive,which was the corresponding pressure of desinent cavitation number.The results show that under the conditions of different sediment concentrations,the desinent cavitation number in the throat of the tunnel first increases and then decreases with the increase in sediment concentration,which shows that the occurrence of cavitation is first promoted and then inhibited compared with clear water.Under the conditions of different sediment grain sizes,the desinent cavitation number in the throat increases with the increase in grain size,indicating that the early occurrence of cavitation is promoted with the increase in sediment grain size.Under the conditions of different sediment gradations,the desinent cavitation number in the throat increases with the increase in mass fraction less than a certain grain size,exhibiting that cavitation was easier to occur with the increase in mass fraction less than a certain grain size.Under the conditions of different mineral compositions,th

关 键 词：消失空化数 矿物成分 颗粒级配 泥沙质量浓度 中值粒径 

分 类 号：TV131.3[水利工程—水力学及河流动力学]