低水头水利枢纽泄水闸闸前冲刷研究  

Scouring Mechanism in Front of the Sluice of Low-Head Hydro-Projects

作　　者：方森松[1] 刘晓平[1] 吴国君[1] 周千凯[1] 乾东岳[1] 

机构地区：[1]长沙理工大学水利工程学院,长沙410076

出　　处：《长江科学院院报》2011年第6期25-29,54,共6页Journal of Changjiang River Scientific Research Institute

基　　金：湖南省自然科学基金项目(04JJ3036);湖南省交通厅科技创新项目(200732)

摘　　要：针对低水头水利枢纽坝前附近的冲刷问题,建立了用于研究闸前三元流的泄水闸物理及数学模型,利用动床物理模型观测了闸前冲坑发展过程,然后采用定床物理模型和三维数学模型研究了闸前冲刷初始时刻、中期时刻及稳定时刻的三维流场。结果表明:冲刷初期水流受挡水闸阻水作用,在闸前近壁区水流下潜形成漩涡,闸前呈现复杂的三元流流态,从而造成闸前床面泥沙大量启动,迅速形成冲坑。在冲刷中后期,下潜水流流速在冲坑内部沿水深方向逐渐减弱,漩涡现象不明显,冲坑发展变缓,最终达到平衡。To elaborate on the river bed scouring in front of the sluice of low-head hydro-projects,physical and mathematical models are built to study the three dimensional flow in front of the sluice.Movable bed physical model is used to observe the development process of the scouring pit.Furthermore,fixed bed physical model and threedimensional turbulence model are employed to simulate the 3-D flow field at the initial,middle and steady period of the scouring.The main conclusion is obtained as follows： at the beginning of scouring,as the flow is obstructed by the sluice,vortexes are formed by the diving flow and a complicated three dimensional flow is generated,thereby causing a large amount of sediment activating in front of the sluice structures.Accordingly,it results in scouring in front of sluice structures rapidly.During the middle and later period,the diving flow in the scouring pit is gradually weakened along the water depth direction,hence the vortex disappears,and the development of the scouring pit slows down and finally reaches equilibrium.

关 键 词：低水头 泄水闸 冲坑 下潜水流 

分 类 号：TV66[水利工程—水利水电工程]