COMPARISON OF HYDRAULIC MODEL EXPERIMENT AND 3-D NUMERICAL SIMULATION ON DISCHARGE CHARACTERISTICS RELATED TO GATELESS PROJECT OF DAM SPILLWAY

Abstract

In the gateless reconstruction of Myodani dam, constructed in 1931 and had become filled up with sediment, it was planned to remove the existing gate pier, raise the dam spillway, and enlarge the sediment flushing gate. In this study, a 1/25 scale hydraulic model experiment and a 3-D numerical simulation were conducted, and the water level distribution and flow velocity distribution upstream and downstream of the dam were measured. A comparison between the numerical results and the experimental data indicated that the calculation result could reproduce the water level from the upstream of the dam to the overflow with sufficient accuracy. Also it was confirmed that the difference of the velocity distribution between the current riverbed and the planned riverbed could be properly calculated.