Selective Withdrawal Riser for Cave Run Lake

摘要

Tests were conducted to determine the hydraulic and selective withdrawal characteristics of the proposed selective withdrawal riser for Cave Run Lake. A 1:18-scale model was used to investigate the hydraulic performance of the proposed add-on riser. Upper limits for satisfactory riser operation were found to depend on (a) submerged orifice flow, (b) adverse pressures, (c) turbulence within the riser, (d) pool or flow control oscillation, and (e) vortices. Pressures within the proposed riser were positive for all discharges up to 2,500 cfs, indicating that adverse pressure conditions will not have as significant an effect on riser discharge as will the other factors. Performance of the stilling basin for single gate operation was evaluated. Selective withdrawal studies were conducted in a 1:41. 1-scale model. Various density profiles were used to study the withdrawal patterns of the proposed riser for different operating regimes. The top riser port nearest the embankment was found to have essentially the same selective withdrawal characteristics as the other ports. (Author)