【作者】 陈华；

【导师】 袁新明； 陈锡林；

【作者基本信息】 扬州大学 ， 水利水电工程， 2003， 硕士

【摘要】 在水利水电工程建设中，面广量大的中小型闸坝工程在我国四化建设中起着重要的作用。但这些工程一般都为低佛汝德数水跃消能，如果消能问题解决不好将影响建筑物的正常运行，甚至危及闸坝工程的安全。本论文针对目前中小型水利工程中低佛汝德数底流消能存在的一系列问题提出一种新的消能形式，利用闸下铺设通路形成对冲水流，一方面与闸下正向出流碰撞消能，另一方面降低第二共轭水深，同时抬高消力池尾水高度使水流能在消力池内发生淹没水跃进行消能。本文分别从水力学方法、水力试验、数值模拟计算对此消能形式进行了探讨和研究，分析了对冲消力池中的水流流态及对下游的影响。本文的主要内容有： 1．对底流消能状况进行了总结。 2．利用水力学方法对对冲消力池进行了理论分析，推导了消能效率等基本公式。并分析了对冲消力池优于常规消力池的原因。 3．对对冲消力池进行了多组试验，测量计算了对冲消力池在不同工况下的消能率、速度场、压力场，对实验数据进行了整理，拟合了如消能率、佛汝德数等水流参数之间的关系，并与理论值进行了比较，结果吻合较好。 4．在直角坐标系下建立控制方程，对对冲消力池流场进行二维数值模拟，计算结果说明RNG k-ε紊流模型较适合于对冲消力池的流场模拟，计算结果与实验资料较为吻合。 研究表明，对冲消力池消能率高，在低佛汝德数工况下消能效率平均提高15％左右，且具有水流稳定，易于控制成淹没水跃，减轻对下游的冲刷和减少消力池长度及防冲槽长度的优点，对下游河床的演变也起着可调控作用，从而节省工程投资，也可节约河道防冲的维修费用，对工程具有实用价值。同时对底流消能的理论有重要意义，其研究成果可为工程设计提供可靠的设计依据。这种消能形式对高水头泄水建筑物及箱式消力池中的消能也值得借鉴，对泄水建筑物的工程布置也有重要的意义。更多还原

【Abstract】 A large number of medium and small size sluices and dams are playing important roles on the hydraulic structures for the modernization of our nation. However, the hydraulic jumps are often used in these structures to dissipate energy under low Froude number. If the problem is not well solved, it would influence the normal operation, even to endanger the safety of the hydraulic structures. In the view of the problems in energy dissipation with hydraulic jump of traditional sluices and dams, a kind of new form is introduced in this paper, which uses of the access placed under the floor of sluice gate to form opposed jet flow, on the one hand it bumped with the direct outflow to dissipate energy; on the other hand it heightens tailwater which makes the flow to form stability hydraulic jump to dissipate energy in the stilling basin. This article approaches a subject on this type of energy dissipator from different aspects, such as hydraulic method, hydraulic experiments and mathematic stimulation. Furthermore it analyses the flow patterns of fluid in the stilling basin and the effect on downstream. The main tasks of this paper are the follows:1. The recent research works about Energy dissipation of hydraulic structures have been summarized.2. The flow of convective stilling basin is theoretically analyzed in hydraulic method. Then basic formula for energy dissipation rate and some other equations are derived. Moreover the causes why the energy disspation of convective stilling basin is superior to that of normal ones are analyzed in theory.3. Many groups of experiments on convective stilling basin are carriedout, and the ratio of energy dissipation, velocity field, pressure field are measured and calculated. According to experimental data, the relation between the ratio of energy dissipation and Froude number is established. The theoretical values are well coincided with the experimental results.3. The governing equations are formulated in rectangular coordinate system, The flow fields of convective stilling basin are simulated by RNG k- ε and k- ε turbulent models. The computed results show that RNG k- ε turbulent model is more successfully used to predict flow field.The research work shows that convective stilling basin has high ratio of energy dissipation. For low Froude numbers the ratio of energy dissipation can averagely be risen by 15% or so; The flow is stable and is easily to be controlled as submerged jump so that it can decrease scouring on downstream and can shorten the length of the stilling basin ; it also can adjust and control the development of the bed river, So it can reduce investment of the project and save maintenance and repair cost of the strand. It has practical values on hydraulic project, as well as important significance in energy dissipation of the hydraulic jump. The examples in this paper provide valuable reference for the design of the facilities of energy dissipator. This type of energy dissipator is applicable not only for outlet structures of low water head but also for outlet structures of high water head or box stilling basin, and also important to arrangement plan of the project.更多还原