泥沙对泄洪建筑物高速水流空化空蚀影响的机理

研究意义：高速水流空化空蚀关系到泄洪建筑物的安全运行。迄今，关于泄洪建筑物中高速水流空化空蚀的研究基本上是在清水中进行的，然而实际泄洪建筑物中的高速水流均为挟沙水流，并且含沙量高、泥沙颗粒级配和矿物成分复杂，泥沙对泄洪建筑物中高速水流的空化空蚀有何影响？其机理何在？迄今尚未明了。本项目旨在揭示泥沙对泄洪建筑物中高速水流空化空蚀影响的机理，对泄洪建筑物的设计、运行和管理具有重要的指导意义。.研究内容：在循环式水洞中，试验研究含沙量（低含沙量、中等含沙量、高含沙量）、泥沙粒径（细颗粒、中等颗粒、粗颗粒）、泥沙颗粒级配、泥沙矿物成分（如石英、长石、方解石、白云石、角闪石、粉粘土类等）对高速水流空化区压力和消失空化数、空蚀区压力和空蚀率的影响，揭示含沙量、粒径、颗粒级配及矿物成分对空化空蚀影响的机理；取典型天然河流沙样，试验研究其含沙量、粒径、颗粒级配及矿物成分对空化空蚀的影响，以资比较。

Cavitation and cavitation erosion of high-velocity flow directly affects the safe operation of flood release structures. So far, the studies of cavitation and cavitation erosion of high-velocity flow in flood release structures have been basically carried out in clear water. However, actual high-velocity flows in flood release structures are all sediment-laden flows with high sediment concentration, complicated sediment grain gradations and mineral constituents. How on earth does sediment affect cavitaton and cavitation erosion of high-velocity flow in flood release structures? And what is the mechanism? These issues have not clearly understood yet. This proposal aims at uncovering the mechanism of effect of sediment on cavitation and cavitation erosion of high-velocity flow in flood release structures, which are of very important guidance to design, operation and management of flood release structures.. In a looped water tunnel, effects of sediment concentration (low, medium and high), sediment grain size (fine, medium and coarse grains), sediment gradation, mineral constituents (quartz, feldspar, calcite, dolomite, hornblende, silt and clay etc.) on pressure and desinent cavitation number within cavitation zone, and pressure and cavitation erosion rate within cavitation erosion zone in high-velocity flow will be experimentally studied. Effect mechanism of sediment concentration, grain size, grain gradation and mineral constituent on cavitation and cavitation erosion will be uncovered. Also, effects of sediment concentration, grain size, grain gradation and mineral constituent of sediment samples from typical natural rivers, on pressure and desinent cavitation number within cavitation zone, and pressure and cavitation erosion rate within cavitation erosion zone in high-velocity flow will be experimentally carried out to make comparisons with the above-mentioned experimental results.