Q=CLeHe3/2cap Q equals cap C cap L sub e cap H sub e raised to the 3 / 2 power : Discharge coefficient, typically around for ogee crests at design head. Lecap L sub e : Effective length, adjusted for contractions from piers ( Kpcap K sub p ) and abutments ( Kacap K sub a
: The ogee profile consists of two quadrants. The downstream profile often follows the equation are constants based on the upstream slope. ogee spillway designxls better
Let’s test the query: Is there any scenario where classic ".xls" is better? Q=CLeHe3/2cap Q equals cap C cap L sub
| Row | Description | Formula / Logic | | :--- | :--- | :--- | | | Unit Discharge ($q$) | =B3/B4 | | 11 | Design Head ($H_d$) | See Note 1 below | | 12 | Approach Velocity ($v_a$) | =B3/(B4*(B5-B6)) (Approximate) | | 13 | Velocity Head ($h_v$) | =(B12^2)/(2*9.81) | | 14 | Total Head ($H_0$) | =B11 + B13 | Let’s test the query: Is there any scenario
If you are currently using graph paper, a calculator, and a PDF of USBR Monograph No. 25, you are leaving efficiency on the table.
Better spreadsheets provide coordinates for the downstream profile (often following the USBR or WES standard shapes) to prevent sub-atmospheric pressure and cavitation.
In manual methods, adjusting ( H_d ) requires re-tabulating the entire crest profile and recomputing discharge. In Excel, change one cell and all downstream calculations—ordinates, velocities, Froude numbers, and energy balance—update instantly. This allows rapid optimization for site-specific hydrology.