综合式消力池常用设计方法存在的问题和应用条件研究

发布时间：2019-01-20 09:03

【摘要】：综合式消力池第三种设计方法为常用设计方法,但在下游水深较大、弗劳德数较小时计算的消力坎高度较大,甚至出现消力坎高度远大于下游水深且消力池深度出现负值的不合理现象。分析综合式消力池常用设计方法存在的问题和应用条件对于工程设计具有重要的指导意义。根据综合式消力池的消力坎后可能发生的水跃现象,分析常用设计方法出现问题的原因,主要是假设消力坎后发生临界水跃与实际水流条件不符。常用设计方法应用的条件为消力坎后下游河床的水流弗劳德数Fr_t大于某一临界弗劳德数Fr_c、或下游水深h_th_k/Fr_c~(2/3),给出了消力坎流速系数ф=0.75~0.98时临界弗劳德数Fr_c的计算公式。探讨了消力坎的极限高度和最小坎高,消力坎的极限高度等于下游水深;给出了最小坎高的计算公式。通过与其它三种计算方法的比较,表明在符合综合式消力池应用条件的情况下,常用设计方法得出的计算结果与其它方法一样具有可靠性。
[Abstract]:The third design method of the integrated stilling pool is a common design method, but the height of the stilling ridges calculated with a small Froude number is larger than that of the lower water depth. There is even unreasonable phenomenon that the height of the stilling bar is much higher than the downstream water depth and the depth of the stilling pool is negative. It is of great significance for engineering design to analyze the problems and application conditions of common design methods of integrated stilling pool. According to the possible water jump after the stilling of the integrated stilling tank, the causes of the problems in the common design methods are analyzed. The main assumption is that the critical water jump after the stilling is not in accordance with the actual flow conditions. The condition that the common design method is applied is that the Froude number Fr_t of the downstream riverbed behind the stilling bar is greater than that of a certain critical Froude number Fr_c, or the downstream water depth HSP / FRP / Frc2 / 3. The formula for calculating the critical Froude number Fr_c when the velocity coefficient of the stilling bar is 0.75 ~ 0.98 is given. The limit height and the minimum height of the stilling ridge are discussed. The limit height of the stilling ridge is equal to the downstream water depth, and the calculation formula of the minimum canister height is given. By comparing with the other three calculation methods, it is shown that the calculation results obtained by the common design methods are as reliable as those obtained by other methods under the condition that the application conditions of the integrated stilling pool are satisfied.
【作者单位】：中国水电建设集团十五工程局有限公司第四工程公司;西安理工大学水利水电学院;浙江省水利水电勘测设计院;
【分类号】：TV653

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