The program online_wes_spillway designs the shape of a WES spillway. The U.S. Army Corps of Engineers has developed several standard shapes at its Waterways Experiment Station. These shapes are referred to as the WES standard spillway shapes. Four types of WES spillways are considered: (1) Type A, 0 H : 3 V, (2) Type B, 1 H : 3 V, (3) Type C, 2 H : 3 V, and (4) Type D, 3 H : 3 V (Fig. 1).
Fig. 1 WES standard spillway shapes.
The computation procedures follow Section 9.2 of "Open-channel Hydraulics," by V. M. Ponce (2014).
The WES shapes follow the equation: X n = K Hd n-1 Y, in which X and Y are the coordinates of the crest profile, with the origin of coordinates at the highest point of the crest; Hd is the design head excluding the velocity head of the approach flow; K and n are parameters which depend on the slope of the upstream face. The values of K and n are shown in Table 1.
Table 1 Values of K and n .
|3 V : 1 H
|3 V : 2 H
|3 V : 3 H
The input data is subject to the following restrictions:
If any of these conditions is not satisfied, execution stops.
- Q > 0
- L > 0
- Ews > Ecf