Download or read book Hydraulic Model Studies of Yellowtail Afterbay Dam Spawning Channel, Stilling Basin and Diffuser Chamber, Missouri River Basin Project, Montana written by G. L. Beichley and published by . This book was released on 1965 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: LIC MODEL STUDIES OF THE SPAWNING CHANNEL STILLING BASIN AND DIFFUSER CHAMBER AT Yellowtail Afterbay Dam in Montana resulted in the use of a slotted baffle near the intake conduit to provide satisfactory stilling action and good flow distribution. Flow enters the spawning channel through a 4-ft-dia intake conduit, passes through a stilling basin, and upward through a diffuser grating into the resting pool at the upstream end. Of the 150-cfs design flow, 30 will be discharged through a 24-in. bypass pipe to lower part of the fish ladder, 20 into the upstream end of the fish ladder, and the rest into the spawning channel. The slotted baffle diffuser was developed for the stilling basin to replace floor block and stepped end sill of the original design. This provided a relatively stable water surface in the basin and good flow distribution from the diffuser chamber into the resting pool, so that flow into and through the pool was quiet. The modified stilling basin and diffuser chamber performed well for any possible operating combination of head and tailwater. To quiet flow from the bypass pipe from main stilling basin before discharging it at right angles into the fish ladder, the bypass diffuser chamber was widened and a seawall-type cover was provided at the downstream end to reduce turbulence. (Author).