Conduits and Howell-Bunger Valves, Narrows Dam, Little Missouri River, Arkansas: Model Investigation
Abstract
The purpose of this investigation was to examine the over-all performance of the conduits and 84-in. Howell-Bunger valves to be used to regulate flow through the outlet conduits of Narrows Dam, with particular attention to discharge coefficients, velocities in the exit area, and pressures on the end sill of the stilling basin. Tests, which were conducted on a 1:16-scale model, demonstrated the need for some type of hood over the valves to prevent flow from being projected onto the access road along the right side of the stilling basin. Hoods having semicircular tops of 8.75-ft radius supported by vertical walls from the basin floor gave satisfactory results. The coefficient of discharge for the combination of the valves without the hoods and the contraction immediately above the valves was found to vary between 0.87 and 0.88. The use of a hood on the valves did not impair the discharge capacity. It was necessary to replace the sloping end sill of the original design with a vertical-faced end sill to maintain a cushion of water in the stilling basin. Pressures on the end sill were not of serious proportions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1951
- Accession Number
- ADA637751