水沙条件变化对河型河势影响的三维数值模拟研究  

3-D numerical simulation of impacts of flow and sediment regime changes on fluvial processes in conceptual channel

作　　者：假冬冬[1,2] 邵学军[2] 周建银[2] 张幸农[1] 

机构地区：[1]南京水利科学研究院水文水资源与水利工程科学国家重点实验室,南京210029 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《水力发电学报》2014年第5期108-113,共6页Journal of Hydroelectric Engineering

基　　金：国家973计划资助项目(2012CB417002);十二五国家科技支撑计划资助项目(2012BAB04B03);国家自然科学基金资助项目(51109140);中央级公益性科研院所基本科研业务费专项(Y213009);交通运输部重大科技专项项目(20113287640)

摘　　要：以概化水槽为例,采用考虑岸滩崩塌变形的三维水沙模型,对不同水沙及岸滩抗冲性条件下的河型河势变化特征进行了数值模拟研究。模拟结果表明:不同流量过程对河床的塑造作用存在显著差异,大水的造床作用往往大于长时期小流量的造床效果,不同的流量过程甚至可能产生不同的河型;黏性细沙的加入有助于稳固边滩(临界剪切应力增加),从而促进曲流的形成;边岸抗冲性弱、大量加入床沙时,主流易散乱,有助于游荡型河道的形成与发展。考虑岸滩崩塌变形的三维水沙模型为河型河势变化的深入研究提供了一有效技术手段。Responses of planform evolution in a conceptual channel to different flow and sediment regimes and different bank resistance against scour were investigated with a 3-D mathematical model, which integrates a 3-D flow and sediment transport module and a bank erosion module. The simulations demonstrate substantial effects of flow process on fluvial processes. Planform evolution in high flow period was much more significant than that in low flow period, and even different channel patterns may develop at different discharge duration curves. Stable channel bends often formed in the condition of enough cohesive sediments featured with greater critical shear stress, while wandering channels tended to form and develop with a low bank resistance against scour and a large amount of bedload transport. A 3-D model considering bank failure is an effective device for investigation of river regime and channel pattem evolutions.

关 键 词：河床演变学 概化河道 水沙变化 河型河势 数值模拟 

分 类 号：TV147[水利工程—水力学及河流动力学]