Ogee Spillway Designxls Better

An ogee spillway features an S-shaped (or ogee) curve. The upper curve conforms closely to the profile of the underside of a nappe—the sheet of water flowing over a sharp-crested weir—at a specific design head ( Hdcap H sub d

: The smooth curve minimizes turbulence and vibrations, making it ideal for concrete gravity, arch, and buttress dams. ogee spillway designxls better

For ultra-high-head dams (typically exceeding 30-40 meters), sub-atmospheric pressure distributions along the profile must be verified using CFD modeling or physical scale models to prevent structural cavitation damage. An ogee spillway features an S-shaped (or ogee) curve

) based on whether the upstream energy head is above or below the design head. It should account for values ranging from approximately in free-flow to in submerged conditions. Profile Precision ) based on whether the upstream energy head

Using Excel's or Goal Seek , the spreadsheet can instantly compute

Engineers who skip the spreadsheet and go straight to 3D modeling often end up with a spillway that looks good but has negative pressure zones (cavitation risk) because their curve didn't perfectly match the nappe. The XLS fixes this first.

Q=C⋅Le⋅He3/2cap Q equals cap C center dot cap L sub e center dot cap H sub e raised to the 3 / 2 power (PDF) Ogee Spillway Profile: Spreadsheet - ResearchGate