东庄水利枢纽无碰撞泄洪消能体型优化研究

发布时间：2018-08-18 13:49

【摘要】：高拱坝泄洪消能的显著特点是窄河谷、高水头、大单宽流量,高速水流及其泄洪消能问题十分突出,消能防护成为关键技术难题之一。二滩工程的消能模式充分表明了空中碰撞消能的优点,但其最大问题在于使泄洪雾化大大增强,对坝体及下游岸坡造成威胁甚至破坏,表中孔空中无碰撞消能是解决这一问题的有效途径,本文结合东庄水利枢纽工程,利用模型试验及数值模拟方法对无碰撞泄洪消能体型进行了优化研究,具体研究工作如下:(1)研究了17种表孔宽尾墩体型方案下表孔的泄流能力、水舌空中扩散特性、水垫塘时均冲击动压等水力特性,并总结了不同体型参数对表孔水力特性的影响规律。与常规宽尾墩体型方案相比,表孔边墙外伸后,水舌纵向扩散长度最大增幅为21.5m,水舌空中形态稳定,冲击压强最大降幅73.9%。(2)提出3种表孔新体型,并与不同中孔体型组合运用于联合泄洪模型试验,得到了不同方案下表孔的泄流能力,表中孔空中无碰撞消能效果,水垫塘时均冲击压强,脉动压强。经过不同方案水力特性比较分析,得出体型方案3水头应用范围最广,表中孔水舌间隙明显,能形成较好的水舌空中无碰撞效果;水垫塘底板最大时均冲击压强值与前2种体型相比最大降幅分别为39.0%、18.1%;脉动压强均方根最大值与前2种体型相比最大降幅分别为58.6%、40.1%,确定了体型方案3为最优方案。(3)采用RNG k-ε三维紊流模型对设计工况下3种体型方案表中孔联合泄洪消能水力特性进行了数值模拟,结果表明计算值与试验值基本吻合,随后用该数值方法研究了不同二道坝高程和位置下水垫塘时均压强分布特性,得出二道坝高度取为34m,位置向上游移动40m为最优化方案。
[Abstract]:The characteristics of high arch dam flood discharge energy dissipation are narrow valley, high water head, large single wide flow, high speed flow and its energy dissipation. Energy dissipation and protection become one of the key technical problems. The energy dissipation mode of Ertan Project fully shows the advantages of collision energy dissipation in the air, but its biggest problem is that the atomization of flood discharge is greatly enhanced, which threatens and even destroys the dam body and the downstream bank slope. Non-collision-free energy dissipation is an effective way to solve this problem. In this paper, the model test and numerical simulation method are used to optimize the energy dissipation type of non-collision-free flood discharge in the Dongzhuang Water Control Project. The specific research works are as follows: (1) the discharge capacity of surface hole under 17 kinds of surface hole wide tail pier configuration scheme, the characteristics of water tongue diffusion in the air, the hydraulic characteristics such as the impact dynamic pressure of water cushion pond, etc., are studied. The influence of different shape parameters on the hydraulic characteristics of the surface hole is summarized. Compared with the conventional wide-tail pier shape scheme, the maximum increase of longitudinal diffusion length of the water tongue is 21.5 m after the sidewall extension of the surface hole, and the air shape of the water tongue is stable, and the maximum drop of the impact pressure is 73.9%. (2) three new types of surface hole are proposed. Combined with different mesopore shapes, the combined flood discharge model test shows that the discharge capacity of the surface hole under different schemes is obtained, the energy dissipation effect of the surface hole in the air without collision, the impact pressure and the pulsating pressure in the water cushion pond are obtained. Through the comparison and analysis of hydraulic characteristics of different schemes, it is concluded that the water head of body type scheme 3 has the most extensive application range, and the gap between the holes in the water tongue is obvious, which can form a better non-collision effect of the water tongue in the air. Compared with the first two types, the maximum impact pressure of the bottom plate is 39.0 and 18.1.The maximum RMS of pulsating pressure is 58.6% and 40.1, respectively. It is determined that the shape scheme 3 is the best. (3) the maximum RMS value of fluctuating pressure is 58.6% and 40.1%, respectively, compared with the former two types of body shape. (3) the maximum RMS value of fluctuating pressure is 58.6% and 40.1% respectively compared with the former two types. RNG k- 蔚 three-dimensional turbulent model is used to simulate the hydraulic characteristics of combined energy dissipation with holes in three types of configuration table under design conditions. The results show that the calculated values are in good agreement with the experimental values. Then, the distribution characteristics of the average pressure at different elevation and location of the second dam are studied. The optimum scheme is that the height of the second dam is 34 m, and the position moving upstream is 40 m.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV653;TV135.2

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