Spillway models are used to:
- Evaluate the capability of the structure to pass flood flows as well as normal discharges
- Rate the spillway crest
- Determine the effect of approach flow conditions on the theoretical discharge rating of the crest
- Measure discharge chute, discharge channel, and stilling basin performance
- Determine water depths and wave patterns (to ensure that wall heights are sufficient to contain the flow)
- Identify local pressures at the surface of structures (to determine the potential for cavitation)
- Develop optimum stilling basin design and heights of baffle blocks and sills
Discharge structures with regulating gates are modeled to:
- Measure headloss
- Identify flow patterns
- Determine local pressures (often approaching cavitation pressure)
Structures discharging into a tunnel are modeled to:
- Identify free surface flows and hydraulic jumps
- Measure the air demand of the jump to ensure stability and prevent fluctuations in the flow
Models can also be used to:
- Determine the need for erosion control to prevent damage to a discharge structure (e.g., spillway)
- Confirm that the capacity of a critical discharge structure is equal to the required design flows so that the integrity of the structure is maintained
