Large amplitude flow hydraulic characteristics of the spillway under Study
|Course||Hydraulic Structure Engineering|
|Keywords||Spillway Shockwave T-shaped pier stilling basin Anti- pick the cover Shape Optimization|
The main purpose of the spillway is designed to meet the requirements of discharge and energy dissipation , T-shaped pier stilling basin structure and stability, not only can significantly improve the energy dissipation rate , but also reduce the pool length , increase economic efficiency. This paper proposes a new energy dissipator : Let pick cover with anti- T-shaped pier, the fortification pick cover prevents high water hit T-shaped pier after pier before soaring , this new energy dissipator , can solve large Change traffic flow under the bottom dissipation problem . Based on the model test , based on the theoretical analysis , in addition to checking the spillway discharge capacity , the emphasis on the T-shaped pier structure improvement and shape optimization are studied. Major research achievements are: 1 . Gives the weir when the reservoir water level and flow curve , when the number of different openings gate opening and flow curves , for practical engineering reference . Studied the diamond shock wave under the influence of surface line chute variation ; and hydraulic parameters derived diamond shock wave calculation formula . 2 T-shaped pier deduced stilling basin water jump equation, drag coefficient , drag and Hom pier energy dissipation rate calculation formula , and verified , the test conditions, can be used in practical engineering calculations . This energy dissipation rate calculation formula for rectangular, trapezoidal stilling basin , rear elevation and bottom sill elevation equal, not equal to apply. 3 to determine the experimental conditions of this model , T-shaped pier stilling basin optimal cell length 52.5 m.. T-shaped pier optimal structure and parameters : (1) T -shaped pier fortification pick the cover , the cover is given anti- pick the optimal parameters ; (2) T -shaped pier pier optimal type : leg ladder , the former pier arc shape. And gives the specific type and dimensions . ( 3 ) T-shaped pier derived impact energy dissipation effect of the important factors: the blocking rate , relative pier , the former pier maximum water blocking area should not be more than 50 % and the relative position pier stilling basin entrance to the T-shaped pier pier before the distance and pool length ratio should be 0.73 . Froude number into the pool is a major impact on the rate of energy dissipation hydraulic parameters , gives a T-shaped pier stilling basin energy dissipation rate and the Froude number into the pool relationship . 4 shows the T-shaped pier plunge pool velocity distribution . By analyzing the flow rate of the T-shaped pier possibility of cavitation , cavitation from the perspective of optimization are given relative pier type . Cavitation number σ is given calculation formula , and the proposed setting chute segment elevation position aerator .