الفهرس | Only 14 pages are availabe for public view |
Abstract In this research an experimental wok was carried out to study the new roughness shape (U-shape), and showing the efficiency of the stilling basin with this roughness. The results of the work are analyzed and discussed. And we got the following conclusions. 1- We can show from the water surface configuration that, the initial water depth of the jump almost constant for all roughness intensities and lengths. And the sequent depth changes slightly by increasing the roughness intensity and roughness length. 2- Empirical formulas were obtained in dimensionless forms, for each roughness intensity and length tested. Each form was found to be related to the initial Froude number F1 by a straight line function for the relative jump length (Lj/Y1) and the relative sequent depth (Y2/Y1), and by a logarithmic function for the relative energy loss (EL/E1). 3- The best roughness intensity which gives minimum jump length, minimum relative sequent depth, and maximum energy loss is 12.5%. 4- The best roughness length which gives minimum jump length, minimum sequent depth, and maximum energy loss is 18.33. 5- The U- shape roughness decreases the relative jump length compared with the rectangular shape approximately by 45%. 6- The U-shape roughness decreases the relative sequent depth compared with the rectangular shape approximately by 11%. 7- The U-shape roughness increases the relative energy loss compared with the rectangular shape approximately by 8%. 8- The U- shape increased the total volume of materials required for the stilling basin roughness elements by 25%. 9- The U-shape stilling basin increases the number of roughness elements that needed for the basin by 58%. 10- The U- shape is more effective than the rectangular shape, but it will needed more accurate workers to make it plus it increase the number of roughness elements and the length of basin. |