B型和D型折坡水跃的水力计算

Hydraulic calculation of B Jump and D Jump

折坡水跃的水力计算是设计折坡水跃消力池时经常遇到的问题。为了得到计算 B型和 D型水跃第二共轭水深的简便有效的计算关系式 ,应用 Microsoft Excel 97和 Visual C++5 .0等软件 ,对坡度从 0 .0 5∶ 1到 0 .3∶ 1的 B型和 D型水跃试验数据进行了分析和研究。指出 B型水跃的第二共轭水深 Tw 与收缩断面水深 D1 、收缩断面佛氏数 F1 、坡角θ、水跃在斜坡上的长度 Ls 及 A型水跃的共轭水深 D2 有关 ,D型水跃的第二共轭水深 Tw 与收缩断面水深 D1 收缩断面佛氏数 F1 、坡角 θ有关。其中 ,在一定的坡角 θ下 ,B型水跃 ( Tw-D2 ) /D1 与 ( Ls/D1 ) 1 .1成正比 ,D型水跃Tw/D1 与 ( 0 .5 F21 + 1) 0 .3 5成正比。并进一步提出计算 B型和 D型水跃第二共轭水深的经验公式。

A systematic study of experimental data of B Jump,where the jump is formed partly in the sloping bortion and partly in the horizontal channel portion,and D jump,where the entire jump is formed on the slops,is made in this paper Several slopes are investiged:from 0 05∶1 to 0 3∶1 Microsoft Excel 97 and Visual C ++ 5 0 are used. The second sequent depth of B Jump can be obtained by means of the initial Froude number,the initial depth of jump,the angle of bed with horizontal and the length of jump on slope The second sequent depth of D Jump can be obtained by means of the initial Froude nmuber,the initial depth of jump and the angle of bed with horizontal New practical equations for the second sequent depth of B Jump and D Jump are proposed Satisfactory agreemant is found between the calculated and experimental results of B Jump and D Jump