Physical modeling of flow over an Ogee spillway and investigation of scale effects by using Froude similarity

Ogee spillways are used to control the discharges and water levels in reservoir. In
some cases, steps and baffle blocks are placed at the stilling basin to change flow
regime supercritical to subcritical and improve energy dissipation. Physical models
are built in the laboratories to represent its real-world prototype; however some
scale effects may arise between models. Two open channel setups, called as model
and prototype, are used in this study. The experiments of the study are performed on
these channels using identical Froude Numbers and geometric scaling ratio of 4:1.
The flow depths at four different points are measured from model and prototype for
28 total head. The results showed that there is 92% consistency between model and
prototype, whereas this consistency was not observed at turbulence existing regions
due to scale effects.