Model-Prototype Conformity: Boulder Dam Outlet Works

The principal hydraulic model tests of the dam outlet works (34), which included flow through the intake tower, penstock turbine, and outlet-valve manifolds, were made on a 5⅝-in. (1 : 64 scale), extremely smooth, sheetmetal model which had a friction coefficient of f = 0.021 at a Reynolds number R of 80,000 and used a maximum of 2 cu ft per sec of water. Performance and efficiency tests of the 30-ft diameter prototype, utilizing a maximum discharge of 20,000 cu ft per sec with measured velocities up to 90 ft per sec and at a Reynolds number of from 40 to 70 × 10⁶, made it possible to obtain data from which various hydraulic features of the model and prototype could be compared.