Spillway Designxls Better: Ogee
[ L_e = L' - 2 \cdot (N \cdot K_p + K_a) \cdot H_e ]
To build or evaluate an effective ogee spillway design spreadsheet, one must understand the core geometric and hydraulic parameters that the file must calculate. The profile of an ogee spillway is divided into two main zones relative to the apex (the highest point of the crest): the upstream curve and the downstream curve. 1. The Design Head ( Hdcap H sub d ogee spillway designxls better
Many free XLS files floating online use the simplified "WES Standard Shape" (P/H_d = Infinity). They fail when you have a submerged crest (low P/H_d ratio < 1.0). [ L_e = L' - 2 \cdot (N
These values ensure that the spillway profile is hydraulically efficient for the specified slope. The Design Head ( Hdcap H sub d
yHd=−K(xHd)nthe fraction with numerator y and denominator cap H sub d end-fraction equals negative cap K open paren the fraction with numerator x and denominator cap H sub d end-fraction close paren to the n-th power
Piers and abutments cause flow contraction, reducing the effective crest length. If ignored, this could lead to overtopping and failure. According to USACE EM 1110-2-1603 guidelines, the effective length ( L_e ) is calculated as:
The "designxls" approach to ogee spillways offers distinct advantages that make it demonstrably better than traditional methods:
[ L_e = L' - 2 \cdot (N \cdot K_p + K_a) \cdot H_e ]
To build or evaluate an effective ogee spillway design spreadsheet, one must understand the core geometric and hydraulic parameters that the file must calculate. The profile of an ogee spillway is divided into two main zones relative to the apex (the highest point of the crest): the upstream curve and the downstream curve. 1. The Design Head ( Hdcap H sub d
Many free XLS files floating online use the simplified "WES Standard Shape" (P/H_d = Infinity). They fail when you have a submerged crest (low P/H_d ratio < 1.0).
These values ensure that the spillway profile is hydraulically efficient for the specified slope.
yHd=−K(xHd)nthe fraction with numerator y and denominator cap H sub d end-fraction equals negative cap K open paren the fraction with numerator x and denominator cap H sub d end-fraction close paren to the n-th power
Piers and abutments cause flow contraction, reducing the effective crest length. If ignored, this could lead to overtopping and failure. According to USACE EM 1110-2-1603 guidelines, the effective length ( L_e ) is calculated as:
The "designxls" approach to ogee spillways offers distinct advantages that make it demonstrably better than traditional methods: