高速水流冲磨与空蚀耦合作用下过流壁面蚀损机理研究

项目名称： 高速水流冲磨与空蚀耦合作用下过流壁面蚀损机理研究

项目编号： No.51479124

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 水利工程

项目作者： 王新

作者单位： 水利部交通运输部国家能源局南京水利科学研究院

项目金额： 84万元

中文摘要： 泄水建筑物的冲磨和空蚀破坏一直是水利水电工程中有待妥善解决的关键技术难题，尤其近年来高坝巨型水电站的建设使泄流速度大幅提高，冲磨和空蚀问题愈加突出。本文针对目前相关研究存在的不足，开展高速水流冲磨与空蚀耦合作用机理研究。利用水力学Bernulli原理实现水沙自动混掺、引入突扩体型抗空蚀措施，发明冲磨与空蚀耦合作用试验装置；借助先进的高速摄像系统捕捉含沙水流空化气泡溃灭瞬间冲击形态，综合水动力特性、振动与噪声、蚀损特征，揭示冲磨与空蚀耦合作用机理；采用环境扫描电镜和数字图像技术研究不同性质材料的蚀损机制，提出冲磨与空蚀耦合作用下融合水流空化数、含沙量、粒径、材料力学特性等参数的蚀损模型；选择合适的边界条件和破坏准则，在有限元框架内建立高速挟沙水流与泄水结构非线性瞬态动力接触分析方法，预测过流壁面的蚀损进程。研究成果将为抗蚀新材料研发和泄水建筑物抗蚀设计提供科技支撑。

中文关键词： 高速水流；冲磨与空蚀；耦合机理；蚀损模型；数值预测

英文摘要： Abrasion and cavitation damage of discharge structures is always one critical technical problem need to be well solved in the hydropower projects. Several large hydropower stations with high dam are built in recent years, whose discharge flow velocity increases obviously, then the erosion of abrasion and cavitation are becoming more serious. Faced to the present shortcomings of correlation research, the mechanism study of coupling effect between abrasion and cavitation will be conducted here. Bernulli principle of hydraulic engineering is employed to make the water and sand mixed automatically, and the cavitation defense technology of sudden expansion body type is adopted to develop the test equipment that can simulate the coupling effect between abrasion and cavitation of high speed flow. The advanced high speed camera system is taken to capture the impulse impact shape of the cavitation flow with sand. Synthesize hydrodynamic characteristics, erosion feature, vibration and sound, the coupling effect mechanism between abrasion and cavitation is revealed. The environmental scanning electron microscope and digital image technology are applied to study the erosion mechanism of different materials, and the erosion model considering the flow cavitation number, sand ratio, sand diameter and the mechanics parameters of the material is proposed. The suitable boundary condition and failure criteria are selected, in the FEM frame, nonlinear transit dynamic contact method is set to simulate the interaction between the high speed flow with sand and the discharge structure to predict the erosion process of the overcurrent wall. The results will present science and technology support for the development of new erosion resistance material and the erosion resistant design of the projects.

英文关键词： high speed flow;abrasion and cavitation;coupling effect mechanism;erosion model;numerical prediction